[PDF] - Deep Underground Neutrino Experiment (DUNE) 1 Technical Proposal 2 PDF Document

SLIDE 1

Deep Underground Neutrino Experiment (DUNE)

1

Technical Proposal

2

23 Feb 2018: First draft of the TP volumes due

3

Volume 2: The Single-Phase Far Detector

4

February 13, 2018

5

SLIDE 2

1

SLIDE 3

List of Figures

1

2.1 The field cages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2

3.1 APA diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

3

3.2 APA dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

4

3.3 APA bolted joint drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

5

3.4 APA full-size mesh drawing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

6

3.5 APA board stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

7

3.6 APA wire board connection to electronics . . . . . . . . . . . . . . . . . . . . . . . . . 11

8

3.7 APA side board model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

9

3.8 APA side board photo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

10

4.1

ptional caption for LoF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

17

11

5.1

ptional caption for LoF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

23

12

6.1 Cartoon schematic of the operation of a double-shift light guide. . . . . . . . . . . . . . 37

13

6.2 Drawing of two ARAPUCAs, each one read-out by 12 SiPMs. This design has been used

14

for the protoDUNE ARAPUCAs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

15

6.3 ARAPUCA and the schematic representation of the operating principle . . . . . . . . . 39

16

6.4 ARAPUCA test at LNLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

17

6.5 ARAPUCA array in protoDUNE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

18

6.6 X-ARAPUCA design (exploded view). . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

19

6.7 TPB-coated acrylic plates after spraying at Indiana University during fabrication of parts

20

for ProtoDUNE-SP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

21

6.8 EJ-280 light guide within darkbox for attenuation scan QA at Indiana University (pre-

22

pared for ProtoDUNE-SP). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

23

6.9 Mounting of the WLS plates to the EJ-280 bar. . . . . . . . . . . . . . . . . . . . . . 48

24

7.1 DAQ Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

25

7.2 Baseline Readout and Buffering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

26

7.3 Arrangement of Components in DUNE Timing System . . . . . . . . . . . . . . . . . . 77

27

7.4 Arrangement of components in Single Phase Timing System . . . . . . . . . . . . . . . 78

28

8.1

ptional caption for LoF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

84

29

8.2 sensor support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

30

8.3 sensorcable support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88

31

ix

SLIDE 12

1

x

SLIDE 13

List of Tables

1

2.1 TPC detection components, dimensions and quantities . . . . . . . . . . . . . . . . . . 3

2

3.1 Prelim physics requirements that motivate APA design parameters . . . . . . . . . . . . 5

3

3.2 APA design parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

4

3.3 Baseline bias voltages for APA wire layers . . . . . . . . . . . . . . . . . . . . . . . . . 8

5

3.4 CuBe wire tensile strength and CTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

6

4.1 Important requirements on the HV system design . . . . . . . . . . . . . . . . . . . . . 18

7

5.1 Important requirements on the TPC Electronics system design . . . . . . . . . . . . . . 24

8

6.1 Important requirements on the PD system design . . . . . . . . . . . . . . . . . . . . . 34

9

6.2 Shrinkage of Photon Detector Materials . . . . . . . . . . . . . . . . . . . . . . . . . . 49

10

6.3 Relative Shrinkage of PD components and APA frame, and mitigations . . . . . . . . . 50

11

7.1 Important requirements on the DAQ system design . . . . . . . . . . . . . . . . . . . . 65

12

8.1 Important requirements on the system design . . . . . . . . . . . . . . . . . . . . . . . 85

13 14

xi

SLIDE 14

Todo list

1

e.g. underground locale/construction, wrapped wires, etcâĂę . . . . . . . . . . . . . . . . . . . 1

2

e.g. brief accounting of each) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

3

Mitch, I (Anne) put this in here; do with what you like. The numbers in this chapter come from

4

ProtoDUNE-SP; fix them for DUNE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

5

Include an image of the entire module, indicating its parts. . . . . . . . . . . . . . . . . . . . . 2

6

Include an image of the overall system, indicating its parts. Show how the system fits into the

7

verall detector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4

8

Anne suggests: Within this section add ref to requirements document when it’s ready, and maybe

9

list the most important half dozen in a table here). E.g., . . . . . . . . . . . . . . . . . . . 5

10

By the end of the volume, for every requirement listed in this section, there should exist an

11

explanation of how it will be satisfied. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

12

Include an image of the subsystem (frame), indicating its parts. Show how the system fits into

13

the overall system (APA). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

14

Include an image of the subsystem (boards), indicating its parts. Show how the system fits into

15

the overall system (APA). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

16

Ideas from the QA plan - topics to address . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

17

It would be nice to coordinate with the interface documents; email to Jack F sent 12/20 . . . . . 14

18

Include an image of each interface in appropriate section. . . . . . . . . . . . . . . . . . . . . . 14

19

Points taken from doc 2145, dune mgmt plan . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

20

I asked Maxine about standardized org charts for each consortium. It would be nice to have these.

21

Anne . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

22

Include an image of the overall system, indicating its parts. Show how the system fits into the

23

verall detector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

17

24

Anne suggests: Within this section add ref to requirements document when it’s ready, and maybe

25

list the most important half dozen in a table here). E.g., . . . . . . . . . . . . . . . . . . . 17

26

By the end of the volume, for every requirement listed in this section, there should exist an

27

explanation of how it will be satisfied. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

28

Include an image of the subsystem, indicating its parts. Show how the system fits into the overall

29

system). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

30

Include an image of each interface in appropriate section. . . . . . . . . . . . . . . . . . . . . . 20

31

Add in appropriate subsections for the pieces that HV interfaces with. These initial ones may not

32

be right. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

33

Some initial text suggested by Anne (in fact the APA section in the protodune SP TDR has a lot

34

f good descriptive text) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

23

35

Include an image of the overall system, indicating its parts. Show how the system fits into the

36

verall detector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

23

37

xii

SLIDE 15

Anne suggests: Within this section add ref to requirements document when it’s ready, and maybe

1

list the most important half dozen in a table here). E.g., . . . . . . . . . . . . . . . . . . . 23

2

By the end of the volume, for every requirement listed in this section, there should exist an

3

explanation of how it will be satisfied. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

4

Whatever the items are... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

5

Include an image of the subsystem, indicating its parts. Show how the system fits into the overall

6

system). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

7

not sure what subsections are needed: power supplies, feedthroughs? . . . . . . . . . . . . . . . 24

8

Include an image of each interface in appropriate section. . . . . . . . . . . . . . . . . . . . . . 26

9

Add in appropriate subsections for the pieces that TPC Electronics interfaces with. These initial

10

nes may not be right. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

26

11

Chapter editor: Wilson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

12

(Length: TDR=10 pages, TP=3 pages) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

13

Content: Segreto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

14

Include an image of the overall system, indicating its parts. Show how the system fits into the

15

verall detector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

31

16

Include summary of simulation status? Szelc/Himmel . . . . . . . . . . . . . . . . . . . . . . . 31

17

Content: Segreto/Warner/Mualem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

18

Anne suggests: Within this section add ref to requirements document when it’s ready, and maybe

19

list the most important half dozen in a table here). E.g., . . . . . . . . . . . . . . . . . . . 33

20

By the end of the volume, for every requirement listed in this section, there should exist an

21

explanation of how it will be satisfied. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

22

Content: Segreto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

23

Content: Segreto/Warner/Mualem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

24

Whatever the items are... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

25

(Length: TDR=50 pages, TP=20 pages) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

26

Content: Conveners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

27

Include an image of the subsystem, indicating its parts. Show how the system fits into the overall

28

system). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

29

Content: Cavanna/Whittington/Machado . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

30

Content: Toups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

31

Content: Whittington . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

32

Content: A.A.Machado (?) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

33

May not have figures integrated yet (or bibliography) - LMM . . . . . . . . . . . . . . . . . . . 38

34

Content: Cavanna/Whittington/Machado . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

35

Content: (1 page) - Cavanna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

36

Content: (2 pages) - Zutshi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

37

Content: (3 pages) - Moreno/Franchi/Djurcic . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

38

rjw: Include comment whether there are differences between the photon collector options . . . . 46

39

Content: (1 page) - Warner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

40

(Length: TDR=40 pages, TP=8 pages) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

41

Content: Cavanna/Whittington/Machado . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

42

Content: (2 pages) - Warner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

43

Insert Dave’s PD Mounting rails in APA frame mpicture . . . . . . . . . . . . . . . . . . . . . . 49

44

Insert Dave’s PD Mounting screws mpicture . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

45

format table better? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

46

Needs better table formatting? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

47

xiii

SLIDE 16

Insert Dave’s 4 deflection pictures here . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

1

Same for bars and ARAPUCAs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

2

Content: (1 page) - Zutshi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

3

Just cold boards? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

4

Content: Cavanna/Whittington/Machado . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

5

Can we have a single section that describes how the bars and/or ARAPUCA are assembled into

6

PC modules or do we need a separate subsub(!)section for each? . . . . . . . . . . . . . . 51

7

Content: (2 pages) Moreno/Franchi/Djurcic . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51

8

Content: (2 pages) - Warner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

9

Content: Kemp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

10

(Length: TDR=10 pages, TP=2 pages) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

11

Include an image of each interface in appropriate section. . . . . . . . . . . . . . . . . . . . . . 52

12

Content: Kemp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

13

(Length: TDR=30 pages, TP=6 pages) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

14

Content: Warner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

15

(Length: TDR=10 pages, TP=2 pages) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

16

Content: Warner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

17

(Length: TDR=5 pages, TP=1 pages) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

18

Content: Segreto/Warner/Mualem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

19

(Length: TDR=20 pages, TP=4 pages) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

20

Content: Segreto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

21

Content: Segreto/Warner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

22

Content: Warner/Mualem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

23

Content: Warner/Mualem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

24

2 Pages - largely generic but some highlighting of SP-specifics. . . . . . . . . . . . . . . . . . . 64

25

Describe figure here. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

26

Include: Raw data rate from WIBs, Josh’s table of data volumes for each event type and the 30

27

PB/year offline limit. Space and thermal power limits. Note, this table may be better put

28

into Section

sec:fdsp-daq-design

7.2 to make this section more generic. . . . . . . . . . . . . . . . . . . . . . . 64

29

Anne suggests: Within this section add ref to requirements document when it’s ready, and maybe

30

list the most important half dozen in a table here). E.g., . . . . . . . . . . . . . . . . . . . 64

31

By the end of the volume, for every requirement listed in this section, there should exist an

32

explanation of how it will be satisfied. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

33

This section may also wish to refer to Fig.

fig:daq-overview

7.1. . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

34

Whatever the items are... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

35

16 Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

36

Describe how the data is received from the detector electronics, and buffered while awaiting a

37

trigger decision, together with any processing that affects stored data. The starting point

38

is data incoming from the WIBs and the end point is corresponding data sitting in memory

39

ready for event building. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

40

Below are from slides bv may show at the Jan WS. Content copied here and now as a starting

41

point. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

70

42

Matt: help! Each RCE consists of a .... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

43

Ideas? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

44

xiv

SLIDE 17

Describe the dataflow infrastructure. This should cover transport of data and trigger information,

1

infrastructure for generating local and global trigger commands (but not their algorithms,

2

that’s next), as well as what happens to the data once a trigger is generated (ie. event

3

building). Figure

fig:daq-readout-buffering-baseline

7.2 may be referenced . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

4

5 Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

5

Include an image of each interface in appropriate section. Can maybe refer to Fig.

fig:daq-overview

7.1 but it

6

currently lacks some of the interfaces. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80

7

Need to receive information on beam spills (Giles) , SNEWS (Alec). . . . . . . . . . . . . . . . . 81

8

1 Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

9

2 Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

10

1 Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

11

2 Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

12

Write a better description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

13

Include an image of the overall system, indicating its parts. Show how the system fits into the

14

verall detector. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

84

15

Anne suggests: Within this section add ref to requirements document when it’s ready, and maybe

16

list the most important half dozen in a table here). E.g., . . . . . . . . . . . . . . . . . . . 84

17

By the end of the volume, for every requirement listed in this section, there should exist an

18

explanation of how it will be satisfied. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

19

Whatever the items are... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

20

Include an image of the subsystem, indicating its parts. Show how the system fits into the overall

21

system). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85

22

provide overview and definition of required CFD, encompassing relevant WBS items for “Sim-

23

ulation studies of fluid dynamics within the cryostat” for the purity monitor system, the

24

temperature measurement system, and the level monitoring... . . . . . . . . . . . . . . . . 85

25

need this one? left out for now . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

26

Include an image of the subsystem, indicating its parts. Show how the system fits into the overall

27

system). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89

28

I am completely making up how many special purpose iFix machines there should be: need input

29

from the cryo people . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90

30

Is this the place for the laundry list of Things to Be Monitored? (but which are not cryo related) 90

31

Glenn’s talk from the parallel session @CERN is a great starting point here . . . . . . . . . . . . 90

32

need this one? not assigned . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

33

This section not needed? Not assigned; may be addressed in earlier sections. . . . . . . . . . . . 91

34

Include an image of each interface in appropriate section. . . . . . . . . . . . . . . . . . . . . . 91

35

Add in appropriate subsections for the pieces that this interfaces with. These initial ones may not

36

be right, or some interfaces may be missing. . . . . . . . . . . . . . . . . . . . . . . . . . 91

37

specify external interface of Cryo Inst. Systems with systems outside the cryostat (with LBNF),

38

detector Interface to LBNF design teams working on the design on cryogenic systems (in-

39

cluding cryogenic piping) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

40

describe interface with LBNF on environmental and building controls . . . . . . . . . . . . . . . 92

41

Describe interface with HV systems, including use of cameras for HV monitoring, and also drift

42

HV, current toroid, ground planes, and field cage pickoffs . . . . . . . . . . . . . . . . . . 92

43

Describe interface with DAQ system, including Interface with DAQ/Electronics groups for a slow

44

controls test facility at SURF, possibly as part of the DAQ test stand . . . . . . . . . . . . 93

45

structure under here is recommended . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

46

xv

SLIDE 18

Chapter 1: Design Motivation 1–1

Chapter 1

1

Design Motivation

2

ch:fdsp-apa-design

1.1 Introduction to Single-Phase Far Detector in DUNE/LBNF

3

sec:fdsp-design-intro

1.2 DUNE Physics

4

sec:fdsp-design-phys

1.2.1 Goals (Oscillation Physics, Supernova Neutrinos, Proton Decay)

5

sec:fdsp-design-goals

1.2.2 Requirements

6

sec:fdsp-design-reqs

1.3 Single-Phase LArTPC for DUNE

7

sec:fdsp-design-tpc

1.4 Operational Principle

8

sec:fdsp-design-op

1.5 Implementation of Single-Phase LArTPC Design at DUNE

9

sec:fdsp-design-impl

e.g. underground locale/construction, wrapped wires, etcâĂę

10

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SLIDE 19

Chapter 2: Overview of the Single-Phase Detector Module Design 2–2

Chapter 2

1

Overview of the Single-Phase Detector

2

Module Design

3

ch:fdsp-ov

2.1 Model of the TPC, and coordinate definitions

4

sec:fdsp-ov-model

2.2 Primary Detector Systems

5

sec:fdsp-ov-sys

e.g. brief accounting of each)

6

Mitch, I (Anne) put this in here; do with what you like. The numbers in this chapter come from ProtoDUNE-SP; fix them for DUNE

7

The elements composing a single-phase detector module, listed in Section

intro:detector

??, include the time

8

projection chamber (TPC), the cold electronics (CE), and the photon detection system (PDS).

9

The TPC components, e.g., anode planes, cathode planes and the field cage, are designed in a

10

modular way. The six APAs are arranged into two APA planes, each consisting of three side-by-

11

side APAs. Between them, a central cathode plane, composed of 18 CPA modules, splits the TPC

12

volume into two electron-drift regions, one on each side of the cathode plane. A field cage (FC)

13

completely surrounds the four open sides of the two drift regions to ensure that the electric field

14

within is uniform and unaffected by the presence of the cryostat walls and other nearby conductive

15

structures.

16

Figure

fig:fc-overview

2.1 illustrates how these components fit together.

17

Include an image of the entire module, indicating its parts.

18

Table

tab:tpc-components

2.1 lists the principal detection elements of the single-phase detector module along with their

19

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 20

Chapter 2: Overview of the Single-Phase Detector Module Design 2–3

Figure 2.1: A view of the TPC field cage and the central cathode plane (CPA). The APAs, which would be positioned at both open ends of the FC, are not shown.

fig:fc-overview

approximate dimensions and their quantities.

1

Table 2.1: TPC detection components, dimensions and quantities Detection Element Approx Dimensions Quantity APA 6 m H by 2.4 m W 3 per anode plane, 6 total CPA module 2 m H by 1.2 m W 3 per CPA column, 18 total in cathode plane Top FC module 2.4 m W by 3.6 m along drift 3 per top FC assembly, 6 total Bottom FC module 2.4 m W by 3.6 m along drift 3 per bottom FC assembly, 6 total End-wall FC module 1.5 m H by 3.6 m along drift 4 per end-wall assembly (vertical drift volume edge), 16 total PD module 2.2 m × 86 mm × 6 mm 10 per APA, 60 total

tab:tpc-components

2.2.1 APAs

2

sec:fdsp-ov-

2.2.2 HV

3

sec:fdsp-ov-

2.2.3 Electronics

4

sec:fdsp-ov-

2.2.4 Photon Detector

5

sec:fdsp-ov-

2.2.5 DAQ

6

sec:fdsp-ov-

2.2.6 Instrumentation: Slow Controls and Cryogenics

7

sec:fdsp-ov-instr

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SLIDE 21

Chapter 3: Anode Plane Assemblies 3–4

Chapter 3

1

Anode Plane Assemblies

2

ch:fdsp-apa

3.1 Anode Plane Assembly (APA) Overview

3

sec:fdsp-apa-ov

3.1.1 Introduction

4

sec:fdsp-apa-intro

Anode Plane Assemblies (APAs) are the far detector elements utilized to sense ionization created

5

by charged particles traversing the liquid argon volume inside the single-phase TPC. The planes

6

are interleaved with Cathode Plane Assemblies (CPAs), as shown in Figure..., to establish the

7

required electric fields and form drift volumes for the charged particles.

8

Include an image of the overall system, indicating its parts. Show how the system fits into the

verall detector.

9

The operating principle is illustrated in Figure... (add figure)

10

An APA consists of a rectangular framework with a fine wire mesh stretched across it, over which

11

are wrapped four layers of sense and shielding wires... ...

12

3.1.2 Design Considerations

13

sec:fdsp-apa-des-consid

The APA design must enable identification of minimum-ionizing particles (MIPs). This is a func-

14

tion of several detector parameters, including: argon purity, drift distance, diffusion, wire pitch,

15

and Equivalent Noise Charge (ENC). DUNE-SP requires that MIPs originating anywhere inside

16

the active volume of the detector be reconstructed with 100% efficiency. The choice of wire pitch,

17

f ∼5 mm, for the wire layers on the APA, combined with key parameters for other TPC sys-

18

tems (described in their respective sections of the TDR), is expected to enable the 100% MIP

19

identification efficiency.

20

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 22

Chapter 3: Anode Plane Assemblies 3–5

DUNE-SP requires that it be possible to determine the fiducial volume (via analysis) to <1%,

1

which in turn requires reaching a vertex resolution of ∼1.5 cm along each coordinate direction.

2

(The fiducial volume, among other factors, determines the number of target nucleons, which is

3

a component in cross section measurements.) The fine granularity of the APA wires enables

4

excellent precision in identifying the location of any vertices in an event, (e.g., the primary vertex

5

in a neutrino interaction or gamma conversion points in a π0 decay), which has a direct impact on

6

reconstruction efficiency. In practice, the resolution on the drift-coordinate (x) of a vertex or hit

7

will be better than that on its location in the y − z plane, due to the combination of drift-velocity

8

and electronics sampling-rate...

9

The size of the APAs is chosen for fabrication purposes, compatibility with over-the-road shipping,

10

and for eventual transport to the 4850 level at SURF and installation into the membrane cryostat

11

f a detector module. Sufficient shock absorption and clearances are taken into account at each

12

stage. The dimensions are also chosen such that an integral number of electronic readout channels

13

and boards fill in the full area of the APA. The modularity of the APAs allows them to be built and

14

tested at off-site production facilities, decoupling their manufacturing time from the construction

15

f the membrane cryostat. ...

16

Anne suggests: Within this section add ref to requirements document when it’s ready, and maybe list the most important half dozen in a table here). E.g.,

17

The initial physics performance requirements that drive the design of the APA are listed in Ta-

18

ble

tab:apaphysicsrequirements

3.1. These are chosen to enable high-efficiency reconstruction throughout the entire active

19

volume of the LArTPC.

20

Table 3.1: Preliminary physics requirements that motivate APA design parameters. Requirement Value MIP Identification 100% efficiency High efficiency for charge reconstruction >90% for >100 MeV Vertex Resolution (x,y,z) (1.5 cm, 1.5 cm, 1.5 cm) Particle Identification Muon Momentum Resolution <18% for non-contained <5% for contained Muon Angular Resolution <1◦ Stopping Hadrons Energy Resolution 1-5% Hadron Angular Resolution <10◦ Shower identification Electron efficiency >90% Photon mis-identification <1% Electron Angular Resolution <1◦ Electron Energy Scale Uncertainty <5%

tab:apaphysicsrequirements

By the end of the volume, for every requirement listed in this section, there should exist an explanation of how it will be satisfied.

21

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SLIDE 23

Chapter 3: Anode Plane Assemblies 3–6

3.1.3 Scope

1

sec:fdsp-apa-scope

The scope of the Anode Plane Assembly (APA) system includes the continued procurement of

2

materials for, and the fabrication, testing, delivery and installation of the following systems:

3

a framework of lightweight, rectangular stainless steel tubing;

4

a mesh layer attached directly to both sides of the APA frame;

5

layers of sense and shielding wires wrapped at varying angles relative to each other;

6

stacked head electronics boards, which are wire boards for anchoring the wires at the top

7

(head) of the APA;

8

capacitive-resistive (CR) boards that link the wire boards to the cold electronics (CE);

9

side and foot boards along the other three edges of the APA with notches and pins to hold

10

the wires in place;

11

modular boxes to hold the CE;

12

comb wire supports, mounted on cross braces distributed along the length of the APA, to

13

prevent wire deflection; and

14

pin/slot pairs on the side edges of adjacent APAs to maintain coplanarity.

15

3.2 APA Design

16

sec:fdsp-apa-design

An APA is constructed from a framework of lightweight, rectangular stainless steel tubing, with

17

a fine mesh covering the rectangular area within the frame, on both sides, that defines a uniform

18

ground across the frame. Along the length of the frame and around it, over the mesh layer, layers

19

f sense and shielding wires are strung or wrapped at varying angles relative to each other, as

20

illustrated in Figure

fig:tpc_apa1

3.1. The wires are terminated on boards that anchor them and also provide

21

the connections to the cold electronics. The APAs are 2.3 m wide, 6.3 m high, and 12 cm thick.

22

The principal design parameters are listed in Table

tab:apaparameters

3.2.

23

Starting from the outermost wire layer, there is first a shielding (grid) plane, followed by two

24

induction planes, and finally the collection plane. All wire layers span the entire height of the

25

APA frame. The layout of the wire layers is illustrated in Figure

fig:tpc_apa1

3.1.

26

The angle of the induction planes in the APA (±35.7◦) is chosen such that each induction wire

27

nly crosses a given collection wire one time, reducing the ambiguities that the reconstruction

28

must address. The design angle of the induction wires, coupled with their pitch, was also chosen

29

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 24

Chapter 3: Anode Plane Assemblies 3–7

Table 3.2: APA design parameters Parameter Value Active Height 5.984 m Active Width 2.300 m Wire Pitch (U,V) 4.669 mm Wire Pitch (X,G) 4.790 mm Wire Position Tolerance 0.5 mm Wire Plane Spacing 4.75 mm Wire Angle (w.r.t. vertical) (U,V) 35.7◦ Wire Angle (w.r.t. vertical) (X,G) 0◦ Number Wires / APA 960 (X), 960 (G), 800 (U), 800 (V) Number Electronic Channels / APA 2560 Wire Tension 5.0 N Wire Material Beryllium Copper Wire Diameter 150 µm Wire Resistivity 7.68 µΩ-cm @ 20◦ C Wire Resistance/m 4.4 Ω/m @ 20◦ C Frame Planarity 5 mm Photon Detector Slots 10

tab:apaparameters

Figure 3.1: Sketch of a ProtoDUNE-SP APA. This shows only portions of each of the three wire layers, U (green), V (magenta), the induction layers; and X (blue), the collection layer, to accentuate their angular relationships to the frame and to each other. The induction layers are connected electrically across both sides of the APA. The grid layer (G) wires (not shown), run vertically, parallel to the X layer wires; separate sets of G and X wires are strung on the two sides of the APA. The mesh is not shown.

fig:tpc_apa1

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 25

Chapter 3: Anode Plane Assemblies 3–8

such that an integer multiple of electronics boards reads out one APA.

1

The wires of the grid (shielding) layer, G, are not connected to the electronic readout; the wires

2

run parallel to the long edge of the APA frame; there are separate sets of G wires on the two sides

3

f the APA. The two planes of induction wires (U and V) wrap in a helical fashion around the

4

long edge of the APA, continuously around both sides of the APA. The collection plane wires (X)

5

run vertically, parallel to G. The ordering of the layers, from the outside in, is G-U-V-X, followed

6

by the mesh.

7

The operating voltages of the APA layers are listed in Table

tab:bias

3.3. When operated at these voltages,

8

the drifting ionization follows trajectories around the grid and induction wires, ultimately termi-

9

nating on a collection plane wire; i.e., the grid and induction layers are completely transparent

10

to drifting ionization, and the collection plane is completely opaque. The grid layer is present for

11

pulse-shaping purposes, effectively shielding the first induction plane from the drifting charge and

12

removing the long leading edge from the signals on that layer; again, it is not connected to the

13

electronics readout. The mesh layer serves to shield the sense planes from pickup from the Photon

14

Detection System and from “ghost” tracks that would otherwise be visible when ionizing particles

15

have a trajectory that passes through the collection plane.

16

Table 3.3: Baseline bias voltages for APA wire layers Anode Plane Bias Voltage Grid (G)

665 V

Induction (U)

370 V

Induction (V) 0 V Collection (X) 820 V Mesh (M) 0 V

tab:bias

The wrapped style allows the APA plane to fully cover the active area of the LArTPC, minimizing

17

the amount of dead space between the APAs that would otherwise be occupied by electronics and

18

associated cabling.

19

In the current design of the DUNE-SP far detector module, a central row of APAs is flanked by

20

drift-fields, requiring sensitivity on both sides. The wrapped APAs allow the induction plane wires

21

to sense drifting ionization originating from either side of the APA. This double-sided feature is

22

not strictly necessary for the ProtoDUNE-SP arrangement, which has APAs located against the

23

cryostat walls and a drift field on one side only, but it is compatible with this setup as the grid

24

layer facing the wall effectively blocks any ionization generated outside the TPC from drifting in

25

to the wires on that side of the APA.

26

The choices of wire tension and wire placement accuracy are made to ensure proper operation of

27

the LArTPC at voltage, and to provide the precision necessary for reconstruction. The tension of

28

5 N, when combined with the intermediate support combs (described in Section

subsec:apa_combs

??) ensure that the

29

wires are held taught in place with no sag. Wire sag can impact the precision of reconstruction,

30

as well as the transparency of the TPC. The tension of 5 N is low enough that when the wires

31

are cooled, which increases their tension due to thermal contraction, they will stay safely below

32

the break load of the beryllium copper wire, as described in Section

subsec:apa_wires

??. To further mitigate wire

33

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 26

Chapter 3: Anode Plane Assemblies 3–9

breakage and its impact on detector performance, each wire in the APA is anchored twice on both

1

ends, with both solder and epoxy.

2

3.2.1 Frame and Mesh

3

sec:fdsp-apa-frames

Include an image of the subsystem (frame), indicating its parts. Show how the system fits into the overall system (APA).

4

The stainless steel frame of the APA (Figure

fig:tpc_apa_frame

3.2) is 6.06 m long, not counting electronics and

5

mounting hardware, and 2.30 m wide. It is 76.2 mm thick, made from imperial size 3-in × 4-in ×

6

0.120-in wall rectangular tubing. The cross pieces have a cross-sectional area of 2 in × 3 in, and are

7

connected to edge pieces using joints, as in Figure

fig:tpc_apa_boltedjointdrawing

3.3. It is mounted in the cryostat with its long

8

axis vertical; multiple APAs are mounted edge-to-edge to form a continuous plane. An electron

9

deflection technique, described in Section

sec:apa:electrondiverter

??, is used to ensure that electrons drawn towards a

10

joint between two APAs will be deflected to one or the other, and not lost.

11

Figure 3.2: An APA showing overall dimensions and main components.

fig:tpc_apa_frame

Figure 3.3: A model of the bolted joint. The holes on the top of the tube are for access to tighten the

screws. The heads actually tighten against the lower hole, inside the tube.

fig:tpc_apa_boltedjointdrawing

A fine mesh screen is glued directly to the steel frame surface, over the frame on both sides. It

12

creates a uniform ground layer beneath the wire planes.

13

The mesh is clamped around the perimeter of the opening and then pulled tight (by opening and

14

closing clamps as needed during the process). When the mesh is taut, a 25-mm-wide strip is

15

masked off around the opening and glue is applied through the mesh to attach it to the steel.

16

Although measurements have shown that this gives good electrical contact between the mesh and

17

the frame, a deliberate electrical connection is also made. Figure

fig:tpc_apa_fullsizemeshdrawing

3.4 depicts the mesh application

18

setup for a full-size ProtoDUNE-SP APA.

19

Figure 3.4: The mesh clamping jig for the full size APA.

fig:tpc_apa_fullsizemeshdrawing

3.2.2 Anchoring Elements and Wire Boards

20

sec:fdsp-apa-boards

Include an image of the subsystem (boards), indicating its parts. Show how the system fits into the overall system (APA).

21

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 27

Chapter 3: Anode Plane Assemblies 3–10

Head Electronics Boards

1

At the head end of the APA, stacks of electronics boards (referred to as “wire boards”) are arrayed

2

to anchor the wires. They also provide the connection between the wires and the cold electronics.

3

All APA wires are terminated on the wire boards, which are stacked along the electronics end of the

4

APA frame; see Figure

fig:tpc_apa_boardstack

3.5. Attachment of the wire boards begins with the X plane (innermost).

5

After the X-plane wires are strung top to bottom along each side of the APA frame, they are

6

soldered and epoxied to their wire boards and trimmed. The remaining wire board layers are

7

attached as each layer is wound. The main CR boards (capacitive-resistive), which provide DC

8

bias and AC coupling to the wires, are attached to the bottom of the wire board stack.

9

Figure 3.5: Left: View of the APA wire board stack, as seen from the top/side. The wire board layers can be seen at the bottom-left of the illustration, X on the bottom (it doesn’t go all the way back, but extends farther forward and has the main CR board attached), followed by U, V, then G (which doesn’t go all the way forward, and has its own CR board attached). Right: the same stack viewed from below.

fig:tpc_apa_boardstack

The outermost G-plane wire boards connect adjacent groups of four wires together, and bias each

10

group through an R-C filter whose components are placed on special CR boards that are attached

11

after the wire plane is strung. The X, U and V layers of wires are connected to the CE (housed

12

in boxes mounted on the APA) either directly or through DC-blocking capacitors. The X and U

13

planes have wires individually biased through 50-MΩ resistors. Electronic components for the X-

14

and U-plane wires are located on a common CR board.

15

Mill-Max pins and sockets provide electrical connections between circuit boards within a stack.

16

They are pressed into the circuit boards and are not repairable if damaged. To minimize the

17

possibility of damaged pins, the boards are designed so that the first wire board attached to the

18

frame has only sockets. All boards attached subsequently contain pins that plug into previously

19

mounted boards. This process eliminates exposure of any pins to possible damage during winding,

20

soldering, or trimming processes.

21

Ten stacks of wire boards are installed across the width of each side along the head of the APA.

22

The X-layer board in each stack has room for 48 wires, the V layer has 40 wires, the U layer 40

23

wires and the G layer 48 wires. Each board stack, therefore, has 176 wires but only 128 signal

24

channels since the G wires are not read out. With a total of 20 stacks per APA, this results in

25

2,560 signal channels per APA and a total of 3520 wires starting at the top of the APA and ending

26

at the bottom. There is a total of ∼23.4 km of wire on the two surfaces of each APA. Many of the

27

capacitors and resistors that in principle could be on these wire boards are instead placed on the

28

attached CR boards to improve their accessibility in case of component failure. Figure

fig:tpc_apa_electronics_connectiondiagram

3.6 depicts

29

the connections between the different elements of the APA electrical circuit.

30

At the head end of the APA, the wire-plane spacing is set by the thickness of these wire boards.

31

The first layer’s wires solder to the surface of the first board, the second layer’s wires to the surface

32

f the second board, and so on. For installation, temporary toothed-edge boards beyond these wire

33

boards align and hold the wires until they are soldered to pads on the wire boards. After soldering,

34

the extra wire is snipped off.

35

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 28

Chapter 3: Anode Plane Assemblies 3–11

Figure 3.6: Diagram of the connection between the APA wires, viewed from the APA edge. The set of wire boards within a stack can be seen on both sides of the APA, with the CR board extending further to the right, providing a connection to the cold electronics, which are housed in the boxes at the far right of the figure.

fig:tpc_apa_electronics_connectiondiagram

CR Boards

1

sec:crboards

The CR boards carry a bias resistor and a DC-blocking capacitor for each wire in the X and U

2

planes. These boards are attached to the board stacks after fabrication of all wire planes. Electrical

3

connections to the board stack are made though Mill-Max pins that plug into the wire boards.

4

Connections from the CR boards to the CE are made through a pair of 96-pin Samtec connectors.

5

Surface-mount bias resistors on the CR boards have resistance of 50 MΩ are constructed with a

6

thick film on a ceramic substrate. Rated for 2.0-kV operation, the resistors measure 0.12 × 0.24

7

inches. Other ratings include operation from −55 to +155 C, 5% tolerance, and a 100-ppm/C

8

temperature coefficient. Performance of these resistors at LAr temperature is verified through

9

additional bench testing.

10

The selected DC-blocking capacitors have capacitance of 3.9 nF and are rated for 2.0-kV operation.

11

Measuring 0.22 × 0.25 inches across and 0.10 inches high, the capacitors feature flexible terminals to

12

comply with PC board expansion and contraction. They are designed to withstand 1,000 thermal

13

cycles between the extremes of the operating temperature range. Tolerance is also 5%.

14

In addition to the bias and DC-blocking capacitors for all X- and U-plane wires, the CR board

15

includes two R-C filters for the bias voltages. The resistors are of the same type used for wire

16

biasing except with a resistance of 2 MΩ. Capacitors are 47 nF at 2 kV. Very few choices exist for

17

surface-mount capacitors of this type, and they are exceptionally large. Polyester or Polypropylene

18

film capacitors that are known to perform well at cryogenic temperatures are used.

19

Side and Foot Boards

20

The boards along the sides and foot of the APA have notches, pins and other location features to

21

hold the wires in the correct position as they wrap around the edge from one side of the APA to

22

the other.

23

G10 circuit board material is ideal for these side and foot boards due to its physical properties

24

alone, but it has an additional advantage: a number of hole or slot features in the edge boards

25

provide access to the underlying frame. In order that these openings are not covered by wires,

26

the sections of wire that would go over the openings are replaced by traces on the boards. After

27

the wires are wrapped, the wires over the opening are soldered to pads at the ends of the traces,

28

and the section of wire between the pads is snipped out (Figure

fig:tpc_apa_sideboardmodel

3.7). These traces are easily and

29

economically added to the boards by the many commercial fabricators who make circuit boards.

30

The placement of the angled wires are fixed by pins as shown in the right-hand picture of Figure

fig:tpc_apa_sideboardphoto

3.8.

31

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 29

Chapter 3: Anode Plane Assemblies 3–12

Figure 3.7: Model of board with wires showing how traces connect wires around openings in the side

boards. The wires are wound straight over the openings, then soldered to pads at the ends of the traces.

After soldering the sections between the pads are trimmed away.

fig:tpc_apa_sideboardmodel

Figure 3.8: Boards with injection molded tooth strips glued on. The left shows an end board with teeth for fixing the position of the longitudinal wires. The teeth there form small notches. The right is a side board for fixing the position of the angled wires where the wires are angled around a pin. (These boards are prototype test pieces and are not used in the production APAs.)

fig:tpc_apa_sideboardphoto

The wires make a partial wrap around the pin as they change direction from the face of the APA

1

to the edge. The X- and G-plane wires are not pulled to the side so they cannot be pulled against

2

a pin. Their positions are fixed by teeth with slots, as shown in the left-hand picture in Figure

fig:tpc_apa_sideboardphoto

3.8.

3

The polymer used for the strips is Vectra e130i (a trade name for 30% glass filled liquid crystal

4

polymer or LCP). It retains its strength at cryogenic temperature and has a CTE similar enough

5

to G10 that differential expansion/contraction is not a problem.

6

Glue and Solder

7

The ends of the wires are soldered to pads on the edges of the wire boards. Solder provides both

8

an electrical connection and a physical anchor to the wires. As an additional physical anchor,

9

roughly 10 mm of the wires are glued near the solder pads. For example, in Figure

fig:tpc_apa_sideboardphoto

3.8, in addition

10

to soldering the wires on the pads shown in the left-hand photograph, an epoxy bead is applied

11

n the wires in the area between the solder pads and the injection-molded tooth strips.

12

Gray epoxy 2216 by 3M is used for the glue. It is strong, widely used (therefore much data is

13

available), and it retains good properties at cryogenic temperatures. A 62% tin, 36% lead and 2%

14

silver solder was chosen. A eutectic mix (63/37) is the best of the straight tin/lead solders but the

15

2% added silver gives better creep resistance.

16

3.2.3 Wires

17

sec:fdsp-apa-wires

Beryllium copper (CuBe) wire is known for its high durability and yield strength. It is composed

18

f ∼98% copper, 1.9% beryllium, and a negligible amount of other elements. The APA wire has

19

a diameter of 150µm (.006 in), and is strung in varying lengths across the APA frame. Three

20

key properties for its usage in the APA are: low resistivity, high tensile or yield strength, and

21

coefficient of thermal expansion suitable for use with the APA’s stainless steel frame.

22

Tensile strength of the wire describes the wire-breaking stress (see Table

tab:wire

3.4). The yield strength

23

is the stress at which the wire starts to take a permanent (inelastic) deformation, and is the

24

important limit stress for this case, though most specifications give tensile strength. Fortunately,

25

for the CuBe alloys of interest, the two are fairly close to each other. Based on the tensile strength

26

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 30

Chapter 3: Anode Plane Assemblies 3–13

f wire purchased from Little Falls Alloy (over 1,380 MPa or 200,000 psi), the yield strength is

1

greater than 1,100 MPa. Given that the stress while in use is around 280 MPa, this leaves a

2

comfortable margin.

3

The coefficient of thermal expansion (CTE) describes how material expands and contracts with

4

changes in temperature. The CTEs of CuBe alloy and 304 stainless steel are very similar. Inte-

5

grated down to 87 K, they are 2.7e-3 for stainless and 2.9e-3 for CuBe

cryo-mat-db

[?]. Since the wire contracts

6

slightly more than the frame during cool-down the wire tension increases. If it starts at 5 N, the

7

tension rises to about 5.5 N when everything is cool.

8

The change in wire tension during cool-down could also be a concern. In the worst case, the wire

9

cools quickly to 87 K before any significant cooling of the frame – a realistic case because of the

10

differing thicknesses. In the limiting case, with complete contraction of the wire and none in the

11

frame, the tension would be expected to reach ∼11.7 N. This is still well under the ∼20 N yield

12

tension. In practice, the cooling will be done gradually to avoid this tension spike as well as other

13

thermal shock to the APA.

14

Table 3.4: Tensile strength and coefficient of thermal expansion (CTE) of beryllium copper (CuBe) wire. Parameter Value Tensile Strength (from property sheets) (psi) 208,274 Tensile Strength (from actual wire) (psi) 212,530 CTE of CuBe, integrated to 87 K (m/m) 2.9e-3 CTE of 304 stainless steel, integrated to 87 K (m/m) 2.7e-3

tab:wire

3.2.4 Quality Assurance

15

sec:fdsp-apa-qa

Ideas from the QA plan - topics to address

16

Work processes: ensure proper training materials for and training of designers, fabricators, etc.

17

Design validation: APA has had design reviews, and is prototyped in ProtoDUNE-SP...

18

Acceptance Testing of procured items?

19

Lessons learned

20

Documents and records for all these things.

21

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 31

Chapter 3: Anode Plane Assemblies 3–14

3.3 Production and Assembly

1

sec:fdsp-apa-prod-assy

3.3.1 Production Plan

2

sec:fdsp-apa-prod-plan

3.3.2 Facility Plans

3

sec:fdsp-apa-facility

3.3.3 Wire Winding Machine

4

sec:fdsp-apa-winding

3.3.4 Tooling

5

sec:fdsp-apa-tooling

3.3.5 Assembly Procedures, Travelers, and Documentation

6

sec:fdsp-apa-assy

3.4 Interfaces

7

sec:fdsp-apa-intfc

It would be nice to coordinate with the interface documents; email to Jack F sent 12/20

8

Include an image of each interface in appropriate section.

9

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 32

Chapter 3: Anode Plane Assemblies 3–15

3.4.1 LBNF Cryostat and Detector Support Structure

1

sec:fdsp-apa-intfc-lbnf-dss

3.4.2 Photon Detection System

2

sec:fdsp-apa-intfc-pds

3.4.3 TPC Electronics

3

sec:fdsp-apa-intfc-elec

3.5 Installation, Integration and Commissioning

4

sec:fdsp-apa-install

3.5.1 Transport and Handling

5

sec:fdsp-apa-install-transport

3.5.2 Integration with PDS and TPC Electronics

6

sec:fdsp-apa-install-pds-elec

3.5.3 Calibration

7

sec:fdsp-apa-install-calib

3.6 Quality Control

8

sec:fdsp-apa-qc

3.6.1 Protection and Assembly (Local)

9

sec:fdsp-apa-qc-local

3.6.2 Post-factory Installation (Remote)

10

sec:fdsp-apa-qc-remote

3.7 Safety

11

sec:fdsp-apa-safety

Points taken from doc 2145, dune mgmt plan

12

IPO provides an installation resource where either critical safety issues exist (for example, crane

13

peration) or effort is needed which spans all detector elements (material transport).

What’s

14

required for APA?

15

Is there a Detector Integration, Testing and Installation (DITI) Group with safety being one aspect

16

f their responsibility?

17

Slow controls safety system – is this relevant?

18

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 33

Chapter 3: Anode Plane Assemblies 3–16

3.8 Organization and Management

1

sec:fdsp-apa-org

3.8.1 APA Consortium Organization

2

sec:fdsp-apa-org-consortium

I asked Maxine about standardized org charts for each consortium. It would be nice to have

these. Anne

3

3.8.2 Planning Assumptions

4

sec:fdsp-apa-org-assmp

3.8.3 WBS and Responsibilities

5

sec:fdsp-apa-org-wbs

3.8.4 High-level Cost and Schedule

6

sec:fdsp-apa-org-cs

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 34

Chapter 4: High Voltage System 4–17

Chapter 4

1

High Voltage System

2

ch:fdsp-hv

4.1 High Voltage System (HV) Overview

3

sec:fdsp-hv-ov

4.1.1 Introduction

4

sec:fdsp-hv-intro

A liquid argon cryostat requires an equipotential plane of high voltage (CPA-plane), and a precisely

5

regulated interior electric field to drive electrons from particle interactions to the sensor planes

6

(APA’s, see volume 3A). This requires planar components (CPA’s) held at high voltage, and

7

formed sets of conductors at graded voltages on the top and bottom (FC’s) and sides (EW-FC’s)

8

f the central drift volume. After a discussion of the materials used in construction, this document

9

will discuss the CPA-plane first, followed by the field shaping components.

10

Include an image of the overall system, indicating its parts. Show how the system fits into the

verall detector.

11

The operating principle is illustrated in Figure

figure-label

??... (add figure)

12

Figure 4.1: required full caption (Credit: xyz)

fig:figure-label

4.1.2 Design Considerations

13

sec:fdsp-hv-des-consid

This section contains best practices and requirements, as well as interferences and experience from

14

ProtoDune. A discussion of MONITORING REQUIREMENTS will also come here.

15

...

16

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 35

Chapter 4: High Voltage System 4–18

Anne suggests: Within this section add ref to requirements document when it’s ready, and maybe list the most important half dozen in a table here). E.g.,

1

Table 4.1: Important requirements on the HV system design Requirement ...

apaphysicsparams

By the end of the volume, for every requirement listed in this section, there should exist an explanation of how it will be satisfied.

2

4.1.3 Scope (Rob)

3

sec:fdsp-hv-scope

The scope of the HV system includes the continued procurement of materials for, and the fabrica-

4

tion, testing, delivery and installation of the following systems:

5

The TPC has a central Cathode Plane (CPA-plane), 7m wide and 6m tall, with two symmetric

6

drift volumes on both sides. The Cathode Plane is assembled from 6 side-by-side Cathode Plane

7

Assemblies (CPA’s). Each CPA is 1.2m in width and 6m tall, formed from 3 vertically stacked

8

modules, and supported from above by the CPA installation rail, through a single link. A CPA

9

consists of a FR4 frame that encloses and supports the resistive panels (modules). Each CPA is

10

approximately 1.1m wide and 6m long and is constructed from three modules. Six CPA’s together

11

form the CPA plane. The sides of the drift volumes on both sides of the CPA-plane are covered by

12

the FC and EW-FC field cage modules to define a uniform drift field of 500V/cm, which decreases

13

gradually over 3.6m from the high voltage CPA (-180kV) to ground potential at the APA sensor

14

planes, . The cathode bias is provided by an external high voltage power supply through an HV

15

feedthrough connecting to the CPA-plane inside the cryostat. The Field Cage modules have two

16

distinctive types: the top/bottom (FC), and the end wall (EW-FC). Each module is constructed

17

from an array of roll-formed aluminum open profiles supported by two FRP (fiber reinforced

18

plastic) structural beams. A resistive divider chain interconnects all the metal profiles to provide

19

a linear voltage gradient between the cathode and anode planes. The top/bottom modules are

20

nominally 2.3m wide by 3.6m long.

21

A ground plane of tiled perforated stainless steel sheet panels is mounted on the outside surface

22

f each of the top/bottom field cage modules with a 20cm clearance. The top and bottom FC

23

modules are supported by the CPAs and APAs. The end wall modules are 1.5m tall by 3.6m

24

long. They are stacked 4 units high to cover the 6m height of the TPC. These EW-FC modules

25

are supported by the installation rails above the APAs and CPAs, which are part of the Detector

26

Support Structure (DSS).

27

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 36

Chapter 4: High Voltage System 4–19

4.2 HV System Design

1

sec:fdsp-hv-design

4.2.1 High Voltage Power Supply and Feedthrough (Sarah)

2

4.2.2 CPA (Vic, Steve)

3

4.2.3 Field Cages

4

Top and Bottom field cages (Mike)

5

Discussion of Top and Bottom field cages comes here.

6

Endwall field cages (Thomas)

7

Discussion of Endwall Field cages comes here.

8

4.2.4 Electrical Interconnections (Glenn)

9

4.2.5 Quality Assurance

10

sec:fdsp-hv-qa

Include an image of the subsystem, indicating its parts. Show how the system fits into the

verall system).

11

4.3 Production and Assembly

12

sec:fdsp-hv-prod-assy

4.3.1 Power Supplies and Feedthroughs

13

sec:fdsp-hv-supplies-feedthroughs

Discussion of parts procurement, assembly, and testing.

14

4.3.2 CPA

15

sec:fdsp-hv-supplies

Discussion of parts procurement, assembly, and testing.

16

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 37

Chapter 4: High Voltage System 4–20

4.3.3 Field Cages

1

Top and Bottom field cages

2

Discussion of parts procurement, assembly, and testing.

3

Endwall field cages

4

Discussion of parts procurement, assembly, and testing.

5

4.3.4 Electrical Interconnections

6

Discussion of parts procurement, assembly, and testing.

7

4.4 Interfaces (Bo)

8

There will be an excellent table of interfaces, and accompanying text.

sec:fdsp-hv-intfc9

Include an image of each interface in appropriate section.

10

Add in appropriate subsections for the pieces that HV interfaces with. These initial ones may not be right.

11

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 38

Chapter 4: High Voltage System 4–21

4.4.1 Interfaces to APA

1

sec:fdsp-hv-intfc-cpa-fc

4.4.2 Interface to DSS

2

sec:fdsp-hv-intfc-dss

4.4.3 Interface to PDS

3

sec:fdsp-hv-intfc-pds

4.4.4 Interface to CE

4

sec:fdsp-hv-intfc-ce

4.4.5 Interface to Calibration

5

sec:fdsp-hv-intfc-cal

4.5 Installation, Integration and Commissioning

6

sec:fdsp-hv-install

4.5.1 Transport and Handling

7

sec:fdsp-hv-install-transport

4.5.2 Integration

8

sec:fdsp-hv-install-pds-elec

4.6 Quality Control

9

There will be excellent quality control, based on documented assembly, testing, transport, and

10

installation procedures.

sec:fdsp-hv-qc

11

4.6.1 Protection and Assembly (Local)

12

sec:fdsp-hv-qc-local

4.6.2 Post-factory Installation (Remote)

13

sec:fdsp-hv-qc-remote

4.7 Safety

14

Safety will be the highest priority at all times. There will be documented assembly, testing,

15

transport, and installation procedures.

16

sec:fdsp-hv-safety

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 39

Chapter 4: High Voltage System 4–22

4.8 Organization and Management

1

sec:fdsp-hv-org

4.8.1 HV System Consortium Organization

2

sec:fdsp-hv-org-consortium

4.8.2 Planning Assumptions

3

sec:fdsp-hv-org-assmp

4.8.3 WBS and Responsibilities

4

sec:fdsp-hv-org-wbs

4.8.4 High-level Cost and Schedule

5

sec:fdsp-hv-org-cs

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 40

Chapter 5: TPC Electronics 5–23

Chapter 5

1

TPC Electronics

2

ch:fdsp-tpc-elec

5.1 System Overview

3

sec:fdsp-tpc-elec-ov

Some initial text suggested by Anne (in fact the APA section in the protodune SP TDR has a lot of good descriptive text)

4

5.1.1 Introduction

5

sec:fdsp-tpc-elec-ov-intro

The TPC Electronics System provides the ... The system includes (whatever it includes), as shown

6

in Figure....

7

Include an image of the overall system, indicating its parts. Show how the system fits into the

verall detector.

8

The operating principle is illustrated in Figure

figure-label

??... (add figure)

9

Figure 5.1: required full caption (Credit: xyz)

fig:figure-label

5.1.2 Design Considerations

10

sec:fdsp-tpc-elec-ov-consid

The TPC Electronics system design must enable... ...

11

Anne suggests: Within this section add ref to requirements document when it’s ready, and maybe list the most important half dozen in a table here). E.g.,

12

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 41

Chapter 5: TPC Electronics 5–24

Table 5.1: Important requirements on the TPC Electronics system design Requirement ...

apaphysicsparams

By the end of the volume, for every requirement listed in this section, there should exist an explanation of how it will be satisfied.

1

5.1.3 Scope and Requirements

2

sec:fdsp-tpc-elec-ov-scope

The scope of the TPC Electronics system includes the continued procurement of materials for, and

3

the fabrication, testing, delivery and installation of the following systems:

4

Whatever the items are...

5

power supplies

6

feedthroughs, ...

7

5.2 System Design

8

sec:fdsp-tpc-elec-design

Include an image of the subsystem, indicating its parts. Show how the system fits into the

verall system).

9

not sure what subsections are needed: power supplies, feedthroughs?

10

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 42

Chapter 5: TPC Electronics 5–25 23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 43

Chapter 5: TPC Electronics 5–26

5.2.1 Grounding and Shielding

1

sec:fdsp-tpc-elec-design-ground

5.2.2 Distribution of Wire-Bias Voltages

2

sec:fdsp-tpc-elec-design-bias

5.2.3 Front-End Mother Board (FEMB)

3

sec:fdsp-tpc-elec-design-femb

Overview

4

sec:fdsp-tpc-elec-design-femb-ov

Front-End ASIC

5

sec:fdsp-tpc-elec-design-femb-fe

ADC ASIC

6

sec:fdsp-tpc-elec-design-femb-adc

COLDATA ASIC

7

sec:fdsp-tpc-elec-design-femb-coldata

Cold Electronics Box

8

sec:fdsp-tpc-elec-design-femb-box

Alternative Designs

9

sec:fdsp-tpc-elec-design-femb-alt

5.2.4 Cold Electronics Feedthroughs and Cold Cables

10

sec:fdsp-tpc-elec-design-ft

5.2.5 Warm Interface Electronics

11

sec:fdsp-tpc-elec-design-warm

5.2.6 External Power and Supplies

12

sec:fdsp-tpc-elec-design-external

5.3 Production and Assembly

13

sec:fdsp-tpc-elec-prod

5.3.1 ASIC Procurement

14

sec:fdsp-tpc-elec-prod-asic

5.3.2 Board Assembly

15

sec:fdsp-tpc-elec-prod-board

5.3.3 Cables

16

sec:fdsp-tpc-elec-prod-cables

5.4 Interfaces

17

sec:fdsp-tpc-elec-intfc

Include an image of each interface in appropriate section.

18

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 44

Chapter 5: TPC Electronics 5–27

Add in appropriate subsections for the pieces that TPC Electronics interfaces with. These initial ones may not be right.

1

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 45

Chapter 5: TPC Electronics 5–28 23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 46

Chapter 5: TPC Electronics 5–29

5.4.1 APAs

1

sec:fdsp-tpc-elec-intfc-apa

5.4.2 DAQ

2

sec:fdsp-tpc-elec-intfc-daq

5.4.3 Other Interfaces

3

sec:fdsp-tpc-elec-intfc-other

5.5 Quality Assurance

4

sec:fdsp-tpc-elec-qa

5.5.1 Initial Design Validation

5

sec:fdsp-tpc-elec-qa-initial

5.5.2 Integrated Test Facilities

6

sec:fdsp-tpc-elec-qa-facilities

ProtoDUNE-SP

7

sec:fdsp-tpc-elec-qa-facilities-pdune

Small Test TPC

8

sec:fdsp-tpc-elec-qa-facilities-small

Additional Test Facilities

9

sec:fdsp-tpc-elec-qa-facilities-other

5.6 Quality Control

10

sec:fdsp-tpc-elec-qc

5.6.1 Production (Local)

11

sec:fdsp-tpc-elec-qc-local

5.6.2 Post-factory Installation (Remote)

12

sec:fdsp-tpc-elec-qc-remote

5.7 Installation, Integration, and Commissioning

13

sec:fdsp-tpc-elec-install

5.7.1 Installation and Integration with APAs

14

sec:fdsp-tpc-elec-install-apa

5.7.2 Cabling

15

sec:fdsp-tpc-elec-install-cabling

5.7.3 Calibration

16

sec:fdsp-tpc-elec-install-calib

5.8 Safety

17

sec:fdsp-tpc-elec-safety

5.9 Organization and Management

18

sec:fdsp-tpc-elec-org

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 47

Chapter 6: Photon Detection System 6–30

Chapter 6

1

Photon Detection System

2

ch:fdsp-pd

Chapter editor: Wilson

3

6.1 Photon Detection System (PD) Overview

4

sec:fdsp-pd-ov

(Length: TDR=10 pages, TP=3 pages)

5

6.1.1 Introduction

6

sec:fdsp-pd-intro

Content: Segreto

7

Liquid Argon is known to be an abundant scintillator and emits about 40 photons/keV when

8

excited by minimum ionizing particles, in absence of electric fields. The passage of ionizing ra-

9

diation in LAr produces excitations and ionizations of the argon atoms which ends up with the

10

formation of the excited dimer Ar2

∗. Photons’ emission proceeds through the de-excitation of the

11

lowest lying singlet and triplet excited states, 1Σ and 3Σ to the dissociative ground state. The

12

de-excitation from the 1Σ state is very fast and has a characteristic time of the order of τfast

13

≃ 6 ns. The de-excitation from the 3Σ state is much slower with a characteristic time of τslow

14

≃ 1.3 µsec, since it is forbidden by the selection rules. The relative abundance of the fast and

15

slow components is related to the ionization density of LAr and depends on the ionizing par-

16

ticle, being 0.3 for electron, 1.3 for alpha particles and 3 for neutrons. This circumstance is at

17

the base of the particle discrimination capabilities of LAr, which is exploited by many experiments.

18 19

In both decays, photons are emitted in a 10 nm band centered around 127 nm, in the Vacuum

20

Ultra Violet (VUV) region of the electromagnetic spectrum.

21

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 48

Chapter 6: Photon Detection System 6–31

1

The paradigm for the detection of LAr scintillation light foresees the use of wavelength shifters

2

since the common (cryogenic) photosensors are not sensitive to VUV radiation due to the lack of

3

transparency of fused silica and glass optical windows. The most widely used wavelength shifter

4

used in combination with LAr is Tetra-PhenylButadiene (TPB), which absorbs VUV photons and

5

re-emits them with a spectrum centered around 430 nm, where most of the photosensors have

6

their maximum Quantum Efficiency. TPB conversion efficincy is known to be high, when com-

7

pared to other wavelength shifters (....), and it is often assumed to be 100%, even if a reliable direct

8

measurement of this relevant quantity is not available in the literature. In large LAr TPC, it is

9

common to use photon collector systems which allow to collect light from large areas and drive it

10

in an efficient way towards the active sensors.

11 12

Scintillation light detection is important in a LAr TPC: it is often used for triggering purposes

13

and T0 time measurements, for the determination of the absolute position of the event inside the

14

active volume, but can also give accurate calorimetric measurements of the deposited energy and

15

is a powerful instrument for particle identification.

16 17

At the moment, the photon detection system of the DUNE Single Phase far detector is required

18

to measure the T0 of non-beam events with deposited energy above 200 MeV (proton decay and

19

atmospheric neutrinos) with high efficiency to enable 3D spatial localization of candidate events.

20

The photon system will provide the T0 timing of events relative to TPC timing with a resolution

21

better than 1 µsec. The minimum light yield requirement is of 0.1 phel/MeV for events near the

22

cathode, which is the farthest region from the Photon Detection System, installed behind the

23

anodic plane. A revision of these requirements is being considered in order to better exploit the

24

characteristics of LAr scintillation light and to improve the performances of the detector for low

25

energy (Supernova) events.

26

Include an image of the overall system, indicating its parts. Show how the system fits into the

verall detector.

27

The operating principle is illustrated in Figure

figure-label

??... (add figure)

28

Include summary of simulation status? Szelc/Himmel

29

6.1.2 Design Considerations

30

sec:fdsp-pd-des-consid

Content: Segreto/Warner/Mualem

31

The photon detection system of the Single Phase DUNE far detector is constrained to be structured

32

into modules shaped in form of thin bars (less then 1 cm thick) with approximate dimensions of

33

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 49

Chapter 6: Photon Detection System 6–32

8 cm × 200 cm by the need of being installed on the mechanical frame of the APA and slided

1

between the wire planes on its two sides.

2

Three different designs of PD modules have been developed and are being considered by the SP

3

PD COnsortium. Two of them are based on the concept of light guides coupled to solid state

4

silicon photomultipliers (SiPM) while the third one, namely the ARAPUCA, is a light trap, which

5

captures the photons inside boxes with higlhly reflective internal surfaces where they are eventually

6

detected by SiPM.

7

The dip-coated light guides are pre-treated commercially-cut acrilic slabs dip coated with a solution

8

f TPB, acrylic and toluene. When toluene evaporates it leaves a thin film of TPB embedded in

9

acrylic matrix which acts as wavelenght shifter. A fraction of the light is captured inside the acrylic

10

bar by total internal reflection and is detected at one end of the bar by an array of SiPM.

11

The double-shift light guides are slightly different, since the conversion and guiding processes of

12

the photons are decoupled. They are constituted by a radiator plate coated by pure TPB (through

13

a spraying process) which is optically ocoupled to a commercial shifting/guiding bar which absorbs

14

the TPB blue light and re-emits it in the green. A fraction of the double-shifted light is captured

15

inside the bar by total internal reflections and again it is detected by an array of SiPM installed

16

at one of its ends.

17

The ARAPUCA module is composed of an array of smaller boxes (of the order of 20) each one

18

acting as a smaller detector. Each box has an optical window made by a dichroic filter deposited

19

with two different wavelength shifters, one on the external side and another on the internal one,

20

which allows the light to get inside the box, but not to exit. The internal surface of each box is

21

lined with a highly reflective material so that the trapped photon can bunch several times. An

22

array of SiPM is installed inside the box and will eventually detect the trapped light.

23

The two guiding bars designs have been developed in the course of the last few years and have

24

reached a reasonable level of maturity and reliability. Further improvements are possible and

25

could come from a double ended read-out, that is installing SiPM at both ends of the bars and

26

coating the smaller sides of the bars with reflective foils. Given the maturity of the technology, the

27

effects of these improvements can be easily predicted through Monte Carlo simulations, eventually

28

combined with the outcomes of the protoDUNE experiment where a large number of bars of both

29

flavors are installed (29 of each type).

30

Both designs have been demonstrated to have attenuation lengths for the trapped light compara-

31

ble to the length of the bars themselves, which ensures a reasonable uniformity along the beam

32

direction. Their absolute efficiency has been measured in a quite reliable way only recently and

33

ranges between 0.1% and 0.2%.

34 35

The ARAPUCA concept, on the other hand, is quite new since it was proposed for the first time

36

in 2015 and was accepted for the installation in protoDUNE in mid 2016. A series of LAr tests

37

have been performed with different realizations of ARAPUCA devices, which resulted in efficien-

38

cies ranging from 0.4% to 1.8%. Monte Carlo simulations show that efficiencies at the level of few

39

per cent could be reasonably reached with few modifications to the design. While the results of

40

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SLIDE 50

Chapter 6: Photon Detection System 6–33

the experimental tests are encouraging, they also show that a deeper understanding of the optical

1

phenomena involved is needed.

2 3

Having the photon detection modules installed only on the anodic plane does not allow to have

4

an uniform light collection over the entire active volume. A possible solution for making the light

5

collection more uniform is to install a reflective foil coated with wavelength shifter on the cathode..

6

It would be very beneficial to remove the 39Ar background which otherwise could cause a huge

7

counting rate for events near the anodic plane. It would also increase the light yield of the detector

8

and could allow to perform calorimetric measurements based on light. This possibility is under

9

study through Monte Carlo simulations and its mechanical feasibility is being discussed with the

10

HV Consortium.

11 12

The actual minimal requirements for the light yield of the PD system is of 0.1 phel/keV near the

13

cathode, which would allow to efficiently detect (> 90%) proton decay events (visible energy > 200

14

MeV). All the three designs satisfies the minimum requirements according to preliminary Monte

15

Carlo studies, but there is a wide consensus inside the Collaboration that an higher light yield

16

would be very beneficial for the detection of low energy Supernova neutrinos and a critical revision

17

f the requirements is taking place.

18

These considerations are driving the actual strategy for the design of the SP FD DUNE far detector

19

design and in particular for the R&D program which will be carried on before the Technical Design

20

Report (mid 2019). A strong effort should be put in exploring the possibilty of increasing the light

21

yield of the detector with the ARAPUCA concept by a factor ten with respect to bars’ read-

22

ut, compatibily with the resources available inside the Consortium, in therms of manpower and

23

fundings. This R&D program will lead the Consortium to define a baseline design for the photon

24

collector and one alternate design for risk mitigation.

25

Cocerning the active photosensors few options are under evaluation. SensL SiPM, which have been

26

heavily used in protoDUNE did not demonstrated to be reliable enugh for cryogenic operations

27

after a modification to their packaging and new vendors are being considered. The plan is to use

28

nly devices which are certified for cryogenic operations by the vendor. There are actually ongoing

29

tests of cryogenic SiPM produced by Hamamatsu and by FBK (Fondazione Bruno Kessler, Italy).

30

The electronic design will be strongly influenced by the outcomes of Monte Carlo simulations,

31

whcich will tell about the relevance of having pulse shape capabilities and how they improve

32

Supernova neutrino detection. These consideration will have a role in defining the read-out scheme

33

and the digitization frequency of the signals.

34

Anne suggests: Within this section add ref to requirements document when it’s ready, and maybe list the most important half dozen in a table here). E.g.,

35

By the end of the volume, for every requirement listed in this section, there should exist an explanation of how it will be satisfied.

36

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SLIDE 51

Chapter 6: Photon Detection System 6–34

Table 6.1: Important requirements on the PD system design Requirement ...

pdphysicsparams

6.1.3 Criteria for photon collection options performance evaluation

1

?

2

Content: Segreto

3

The performances of the different photon collection options will be evaluated in the facilities

4

available to the Consortium which will allow to perform relative and absolute measurements at

5

room and cryogenic temperature.

6

An important piece of information will come from the protoDUNE experiment, which is being

7

constructed at CERN and will be operated starting from the second half of 2018.

8

All the three different designs are present in protoDUNE, in particular 29 double-shift guides,

9

29 dip-coated guides and 2 ARAPUCA arrays. The presence of the Time Projection Chamber

10

will allow to precisely reconstruct in 3D the track of any ionizing event inside the active volume.

11

The matching of the track with the associated light signal will enable to accurately estimate the

12

relative detection efficiencies of the installed PD modules. Absolute measurements will be possible

13

depending on the accuracy of the Monte Carlo simulations of the optical properties of the detector.

14

Unfortunately the fact that some of the optical parameters which regulate VUV light propagation

15

in LAr are poorly known, such as Ryleigh scattering length, will influence the precision of the

16

absolute measurements.

17

The protoDUNE test will also give the opportunity of performing long term test of the PD mod-

18

ules for the first time. It will be possible to verify if there is a decay in their performances and

19

eventually to quantify it. This is a relevant information, which needs to be taken into account also

20

in the final design of the modules to ensure that the minimal requirements are satisfied along the

21

whole life of the DUNE experiment.

22 23

The R&D program will go on in parallel with the protoDUNE operation and more comparative

24

measurements will be needed before the Technical Design Report, when a baseline design will

25

be singled out. The TallBo facility at Fermilab will be extremely important to this scope. It is

26

constituted by a 450 liters cryostat with 56 cm inner diameter and up to a 183 cm liquid depth

27

and allows to host up to three different PD modules with dimensions close to the real ones.

28

Other facilities are accessible to the Consortium which will allow to test smaller scale prototypes

29

f the modules (or a piece of them), like the SCENE set-up at Fermilab, the cryogenic facilities at

30

Colorado State UNiversity and UNICAMP (Brazil) and the optical facilities at Fermilab, Indiana

31

University and UNICAMP. These facilities will be useful for the single modules optimization

32

process.

33

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Chapter 6: Photon Detection System 6–35

6.2 Scope

1

The scope of the photon detector (PD) system for the DUNE far detector reference design includes

2

design, procurement, fabrication, testing, delivery and installation of the following components:

3

light collection system;

4

silicon photo-multipliers (SiPMs);

5

readout electronics;

6

calibration system (???)

7

realted infrastructures

8

6.2.1 Scope

9

sec:fdsp-pd-scope

Content: Segreto/Warner/Mualem

10

The scope of the Photon Detection system includes the continued procurement of materials for,

11

and the fabrication, testing, delivery and installation of the following systems:

12

Whatever the items are...

13

Photon Collectors

14

SiPMs

15

...

16

6.3 PD Design

17

sec:fdsp-pd-design

(Length: TDR=50 pages, TP=20 pages)

18

Content: Conveners

19

Include an image of the subsystem, indicating its parts. Show how the system fits into the

verall system).

20

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SLIDE 53

Chapter 6: Photon Detection System 6–36

6.3.1 Photon Collector

1

sec:fdsp-pd-pc

Content: Cavanna/Whittington/Machado

2

At the time of the Technical Proposal there are three photon collector options under consideration,

3

in the following we summarize the design and development status for each. [For the Technical

4

Design Report there will be a baseline design and an alternate.]

5

Dip-Coated Light Guides (4 pages)

6

ssec:fdsp-pd-pc-bar1

Content: Toups

7

Double-Shift Light Guides (4 pages)

8

ssec:fdsp-pd-pc-bar2

Content: Whittington

9

The double-shift light guide photon collector design aims to maximize the active VUV-sensitive

10

area of the photon detection system module while minimizing the necessary photocathode (SiPM)

11

coverage. Commercially-fabricated plastic can be manufactured to transport light via total internal

12

reflection with low attenuation losses. However, direct application of coatings to such manufactured

13

ptical surfaces can have an adverse impact on the effective attenuation length by introducing or

14

exaggerating imperfections in the surface quality. To maintain the long intrinsic attenuation length

15

f a manufactured light guide, the double-shift light guide design decouples the conversion of VUV

16

photons to optical by arraying acrylic plates coated with TPB in front of a commercially-fabricated

17

polystyrene light guide doped with a second wavelength-shifting compound.

18

Description Figure

fig:DoubleShiftLG-Cartoon

6.1 illustrates the process by which LAr scintillation photons are converted

19

and detected by a double-shift light guide module. VUV scintillation photons impinging on the

20

acrylic plates are converted to blue wavelengths. A portion of these blue photons penetrate the

21

light guide and are converted to green. The isotropic re-emission of these green photons leads to a

22

significant fraction becoming trapped by total internal reflection within the light guide. Trapped

23

photons are transported to the end of the light guide where they are detected by an array of SiPMs.

24

Wavelength-Shifting Plates Acrylic spray-coated with TPB. TPB absorption and emission

25

properties.

26

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SLIDE 54

Chapter 6: Photon Detection System 6–37

SiPM Array 128 nm LAr scintillation light 430 nm shifted light from plate ~490 nm shifted light (in bar) 76.2 cm 8.6 cm

Figure 6.1: Cartoon schematic of the operation of a double-shift light guide.

fig:DoubleShiftLG-Cartoon

Wavelength-Shifting Light Guide EJ-280 light guides manufactured by Eljen Technologies1.

1

EJ-280 absorption and emission properties. PDE of SiPMs.

2

Testing The double-shift light guide design has undergone a series of development iterations to

3

improve its performance, carried out at Indiana University and at Fermi National Laboratory’s

4

cryogenic and vacuum test facility (PAB). Comparative testing of light guide designs at PAB in

5

mid-2015 demonstrated the double-shift light guide concept

bib:JINST-11-C05019

[?]. An improved design similar to

6

that deployed at ProtoDUNE-SP was studied at the Blanche test stand at Fermilab in September

7

f 2016 with a complementary component-wise analyis program at Indiana University afterward,

8

detailed in Ref.

bib:DoubleShiftLG-NIM-171113

[?]. The attenuation characteristics of this light guide were measured at Indiana

9

University, while the global quantum efficiency for detecting incident LAr scintillation photons was

10

measured with a vacuum-ultraviolet monochromator at Indiana University and using scintillation

11

light from cosmic rays at the Blanche test stand.

12

Performance Analysis of the double-shift light guide’s attenuation properties determined an

13

attenuation profile in LAr characterized by a double-exponential function of the form f(z) =

14

A exp(−z/λA) + B exp(−z/λB) with z the distance from the instrumented end and parameters

15

A =0.29, λA =4.3cm, B =0.71, and λB =225 cm

bib:DoubleShiftLG-NIM-171113

[?]. The effective attenuation length is comparable

16

to the width of an APA when the double-shift light guide is deployed in liquid argon.

17

Using both approaches the global quantum efficiency of this detector was determined to be 0.48%

18

at the readout end. Combined with the attenuation function and integrated over the area of

19

the module dimensions planned for the DUNE far detector, this corresponds to an effective area

20

for detecting VUV scintillation photons of 3.7 cm2 per module. Wavelength-shifting plates are

21

deployed on both sides of the light guide, meaning the double-shift light guide modules in the

22

center APA array are sensitive to scintillation light from two drift volumes and modules in the

23

uter arrays are able to detect scintillation light originating outside of the TPC volume.

24

Simulated response of this module within the DUNE single-phase far detector module indicates

25

this module efficiency should result in an average efficiency for the photon detection system to

26

detect light from neutrino interactions from a galactic supernova of between 30% at 5 MeV and

27

70% at 15 MeV of visible energy.

28

1http://www.eljentechnology.com

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SLIDE 55

Chapter 6: Photon Detection System 6–38

Potential Improvements for the DUNE Far Detector The double-shift light guide deployed in

1

the ProtoDUNE-SP APAs was constrained to readout at a single end. Proposed changes to the

2

APA size and cabling routing scheme for the DUNE single-phase far detector would allow for a

3

second array of SiPMs at the opposite end of the light guide. This would double the performance

4

f the photon detection system, raising the per-module effective area to 7.4 cm2 per module per

5

drift volume.

6

An SiPM with a wavelength-dependent PDE that is better matched to the EJ-280 emission spec-

7

trum would improve the overall efficiency. Simulations of the transport of light within the light

8

guide suggest that applying a highly reflective coating to the long, narrow inactive sides of the

9

light guide would further boost the attenuation function and further increase effective area of the

10

light guide module. These effects combined lead to a potential increase of the effective area to 15

11

cm2 per module per drift volume.

12

The simulated supernova neutrino detection capability of a photon detection system based on this

13

module depends strongly on small changes in the estimated efficiency. The potential improvements

14

described above raise the physics performance in this channel into a regime where small fluctuations

15

in the module efficiency have a smaller impact on the efficiency to detect these supernova neutrino

16

interactions. These improvements are an important component to risk mitigation in the photon

17

detection system performance.

18

ARAPUCA (4 pages)

19

ssec:fdsp-pd-pc-arapuca

Content: A.A.Machado (?)

20

May not have figures integrated yet (or bibliography) - LMM

21

The ARAPUCA is a device based on a new technology that should allow to collect photons with a

22

window of big area with detection efficiencies at the level of several percent while using a coverage

23

with active devices at the permil level. The idea at the basis of the ARAPUCA is to trap photons

24

inside a box with highly reflective internal surfaces, so that the detection efficiency of trapped

25

photons is high even with a limited active coverage of its internal surface

arapuca_jinst

[?].

26 27

Photons trapping is achieved by using a smart wave-shifting technique and the technology of the

28

dichroic shortpass optical filters. The latter are multilayer thin films with the property of be-

29

ing highly transparent to photons with a wavelength below a tunable cut-off while being almost

30

perfectly reflective to photons with wavelength above the cut-off. A dichroic shortpass filter de-

31

posited with two different wavelength shifters (one on each side) will be the core of the device.

32

In particular, it will be the acceptance window of the ARAPUCA. The rest of the device will

33

be a flattened box with internal surfaces covered by highly reflective acrylic foils (3M-VIKUITI

34

ESR

VIKUITI

[?], for example), closed on the top by the dichroic filter deposited with the two shifters. In

35

principle the box can be filled with any kind of transparent material, since it is inessential to its

36

peration. A fraction of the box internal surface is occupied by the active photo-sensors (Silicon

37

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SLIDE 56

Chapter 6: Photon Detection System 6–39

Photomultipliers - SiPM) that detect trapped photons (figure

arpk

6.2).

1

Figure 6.2: Drawing of two ARAPUCAs, each one read-out by 12 SiPMs. This design has been used for the protoDUNE ARAPUCAs.

arpk

The operating principle is straightforward.

2

The shifters deposited on the two faces of the dichroic filter, S1 and S2 respectively, must have

3

their emission wavelengths, L1 and L2, such that: L1 < Lcut−off< L2, where Lcut−off is the cut-off

4

wavelength of the filter, that is the limit between the region of full transparency (typically > 95%)

5

and that of full reflectivity (typically > 98%). The side of the filter deposited with S2 faces the

6

internal part of the box.

7

Assuming that the ARAPUCA, observes a LAr volume, scintillation VUV photons (λ ∼ 127 nm)

8

produced by the passage of an ionizing radiation, hit the window of the device and are shifted

9

to a wavelength of L1 by the shifter deposited on the external face of the filter and enter the

10

ARAPUCA. Once passed the filter, the photons are converted to the wavelength L2 and are forced

11

to remain trapped inside the box: its internal surface is covered with an almost perfect reflector to

12

L2 and the filter that closes the box is itself reflective to L2 photons. Photons are trapped inside

13

the box. After few reflections the photons are detected by the active photo-sensor installed on the

14

internal surface of the ARAPUCA (figure

arapuca

6.3).

15

The net effect of the ARAPUCA is to amplify the active area of the SiPM used to readout the

16

trapped photons. It is easy to show that for small values of SiPM coverage of the internal surface

17

the amplification factor is equal to

18

A = 1 2(1 − R) (6.1) where R is the average value of the reflectivity of the internal surfaces. For an average reflectivity

19

f 0.95 the amplification factor is equal to ten.

20

Figure 6.3: ARAPUCA and the schematic representation of the operating principle

arapuca

6.4 Tests of the technology

21

testsec

6.4.1 Tests performed in Brazil

22

subsec:testlnls

Tests of the ARAPUCA in a liquid argon (LAr) environment were performed at the facilities of the

23

Toroidal Grating Monochromator (TGM) beamline of the Brazilian Synchrotron Light Laboratory

24

(LNLS) (Fig.

LNLS_test

6.4).

25

A small ARAPUCA made of PTFE with internal dimensions of 3.5x2.5x0.6 cm3 was tested and

26

a dichroic filter with dimensions of 3.5x2.5 cm2 and cut-off at 400 nm was used as the window

27

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SLIDE 57

Chapter 6: Photon Detection System 6–40

f the device. The filter was evaporated with p-TerPhnyl (pTP), which absorbs 127 nm photons

1

and reemits them around 350 nm, on the external side and TetraPhnyl-Butadiene (TPB) on the

2

internal side, which absorbs the shifted 350 nm photons and reemits around 430 nm. Trapped light

3

was detected by a single 0.6x0.6cm2 SensL SiPMs mod C60035. The device was installed inside

4

a vacuum tight stainless-steel cylinder closed by two CF100 flanges. The cylinder was deployed

5

inside a LAr open bath, vacuum pumped down to a pressure around 10−6 mbar and then filled

6

with one liter of ultra pure liquid argon.

7

LAr scintillation light emission was produced by an alpha source installed in front of the ARA-

8

PUCA, immersed in liquid argon. Signals were read-out through an Aquiris PCI board and stored

9

n a computer.

10 11

Figure 6.4: ARAPUCA test at LNLS

LNLS_test

It was possible to estimate the detection efficiency of the ARAPUCA by determining the number

12

f photo-electrons detected in correspondance of the end point of the α spectrum and comparing

13

it with the expected number of photons impinging on the acceptance window for that particular

14

energy value (∼ 4.3 MeV), which depends only on known properties of LAr and on the solid anlge

15

subtended by the the ARAPUCA window. A detection efficiency at the level of 1.8 % was found,

16

well consistent with Monte Carlo expectations.

17

6.4.2 Tests performed at FERMILAB

18

subsec:test_fnal

Three cryogenic tests have been performed at Fermilab up to now:

19

the first one was performed in mid-2016 at the Proton Assembly Building (PAB) and the

20

SCENE facility was used. The ARAPUCA prototype had dimensions of 5.0 × 5.0 × 1.0 cm3

21

with a dichroic window of 5.0 × 5.0 cm2 deposited with pTP and TPB, respectively on the

22

internal and external faces. The cut-off of the filter was at 400 nm. Two SensL SiPMs

23

mod C60035 (0.6 × 0.6 cm2 active area each) were installed inside the box to detect trapped

24

photons. The ARAPUCA was deployed inside a vacuum tight cryostat filled with ultrapure

25

LAr. An 241Am alpha source was positioned in front of the window of the device at a distance

26

f 5 cm from its center. The efficiency of the ARAPUCA was estimated taking into account

27

that in this case the alpha particles have a monochromatic energy of about 5.4 MeV. The

28

estimated efficiency in this case was of the order of 1 %, a factor two below what expected

29

due to the sub-optimal quality and uniformity of the pTP and TPB films and to the lack of

30

reflectivity of the inner PTFE surfaces;

31

the second one was performed at the beginning of 2017 at the PAB, but using a different

32

facility, TallBo, which allowed to test several devices at a time. Eight different ARAPUCAs,

33

with different filters (different producers), different reflectors and different dimensions where

34

tested. The ARAPUCAs were exposed to the 127 nm scintillation light produced by alpha

35

particles emitted by an 241Am source, mounted on a holder which could be moved with an

36

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SLIDE 58

Chapter 6: Photon Detection System 6–41

external manipulator in order to place it in front of each prototype. The efficiencies of the

1

installed ARAPUCAs ranged from 0.4 % to 1.0 %.

2

a third test ws performed at the end of 2017 with an array of eight ARAPUCAs together with

3

two guiding bars (double-shift design) in the TallBo set-up. Data analysis is still ongoing.

4

6.5 ARAPUCA in protoDUNE

5

Two arrays of ARAPUCAs are going to be installed inside protoDUNE to test the devices in a real

6

experimental environment and to directly compare their performances with those of the guiding

7

bars. The first array has been already installed in the APA 3, while the second one will be installed

8

in the APA number 4.

9

Each ARAPUCA arrays is composed by sixteen basic cells. Each cell has the dimensions of 8 cm

10

× 10 cm and is observed by 12 SiPMs (or 6 SIPMs) installed on the bottom side of the cell (6

11

mm × 6 mm each) and which are passively ganged together, so that only one read-out channel is

12

needed for each ARAPUCA (16 channels per array). The ARAPUCA array has total dimensions

13

f approximately 8 cm × 200 cm, exactly the same of a shifting/guiding bar. The first ARAPUCA

14

array installed in protoDUNE is shown in figure (Fig.

arapuca_array

6.5). Figure 6.5: ARAPUCA array in protoDUNE

arapuca_array

15

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Chapter 6: Photon Detection System 6–42

6.6 Last Considerations

1

The ARAPUCA device is undergoing a strong R&D program which aims to establish its viability

2

as the photon detection system of the single phase DUNE far detector, both in terms of absolute

3

detection efficiency and long term reliability. Since this is a new technology, a strong effort needs

4

to be put in this program in order to reach a full comprehension of the optical processes which are

5

active in the device and reach the target efficiency of few per cent.

6

Hybrid or New Options (2 pages)

7

ssec:fdsp-pd-pc-new

6.6.1 New Techniques to Supplement or Enhance Light Yield

8

sec:fdsp-pd-enh

Content: Cavanna/Whittington/Machado

9

Light Concentrators

10

sec:fdsp-pd-assy-lc

Content: (1 page) - Cavanna

11

In the current baseline layout, the photosensitive area of the PD system is limited to about 12.5%

12

f the area of the anode plane - delimiting one side of the LArTPC volume. Only a small fraction

13

f the VUV direct light emitted in ionization events is thus intercepted by the photosensitive area,

14

and this fraction also quickly reduces at increasing distance of the event from the anode plane.

15

Methods to increase the amount of light collected by the PDS are being considered, for example

16

by covering the opposite cathode plane with wls-coated reflector foils so that a good fraction of

17

the VUV light is shifted into the Visible, reflected back toward the Anode plane and eventually

18

intercepted by the PDS, if sensitive to this wavelength.

19

Further increase in light collection, both for the VUV and the reflected Vis component, can be

20

achieved by implementing large area reflective surfaces at the anode plane (e.g. in the large open

21

areas between PD bars inside the APA frames) acting as light concentrators toward the smaller

22

photosensitive surfaces. This conceptual solution is suggested from the widely diffused implemen-

23

tation of Winston Cones for enhancing light collection in large volume liquid detectors. The PD

24

bar geometry of the photosensitive area inside the thin APA frames and the related mechanical

25

constraints impose rather severe limitations on the design - cone depth and entrance/exit aper-

26

tures ratio - of the light concentrating surfaces. The installation of the reflective surfaces inside

27

the APA frame would necessarily be made before wire winding. Ongoing studies are expected to

28

demonstrate the feasibility of the solution and move the conceptual scheme into a technical design.

29

MC simulations will determine the efficiency of the light concentrator.

30

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SLIDE 60

Chapter 6: Photon Detection System 6–43

Hybrid and New Options

1

X-ARAPUCA represents the main line of development of the ARAPUCA photo-detector design

2

aiming to further improve the collection efficiency, while retaining the same working principle,

3

mechanical design and active photo-sensitive coverage.

4

In a sense X-ARAPUCA is a hybrid solution between the ARAPUCA and the wavelength-shifting

5

light guide bar PDS concepts, where photons trapped in the ARAPUCA box are shifted and

6

transported to the readout via total internal reflection in a light guide placed inside the box.

7

This solution minimizes the number of reflections on the internal surfaces of the box and thus

8

the probability of photon loss. Simulations suggest that this modification will lead to a rather

9

significant increase of the collection efficiency.

10

Figure 6.6: X-ARAPUCA design (exploded view).

fig:exploded

In a standard ARAPUCA the photon trapping effect is obtained by means of a dichroic filter and

11

a two-steps wavelength shifting process, the first from VUV to UV outside the acceptance window

12

f the box and the second inside from UV to blue, across the filter cutoff. Double shifted photons

13

are eventually collected by an array of photosensors (SiPM) distributed on the backplane of the

14

box, opposite to the the acceptance window. In the X-ARAPUCA design, Fig.

fig:exploded

6.6, the inner shifter

15

coating/lining over the reflective walls of the box is replaced by a thin wavelength-shifting light

16

guide slab inside the box, of the same dimensions of the acceptance filter window and parallel to

17

it. The SiPM arrays are installed vertically on the sides of the box, in optical contact to the light

18

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SLIDE 61

Chapter 6: Photon Detection System 6–44

guide thin ends. In this way a fraction of the photons will be converted inside the slab and guided

1

to the read-out, other photons, e.g. those at small angle of incidence below the critical angle of

2

the light guide slab, after conversion at the slab surface will be remain trapped in the box and

3

eventually collected as for the standard ARAPUCA.

4

A full sized X-ARAPUCA prototype is under construction. The light guide is made by a 2 mm

5

thick TPB doped acrylic slab. Specially designed read-out boards have been realized, made of 6

6

passively ganged SiPMs in a strip configuration. Two boards into a single channel readout light

7

signals from the X-ARAPUCA box.

8 9

The photon detectors described in the preceding section represent the results of a long process

10

f optimization of the initial concepts developed years ago. A balance between the cost of the

11

readout electronics (channel count), and the cost and performance of the SiPM’s was achieved

12

with realistic designs of the photon detectors offering the detection efficiency in the range ∼ 0.5

13

to 1.5%.

14

A significant advances in the technology of the SPM’s have been accomplished during this time:

15

the photosensors dark count, after-pulsing and cross-talk rates have been lowered by almost an

16

rder of magnitude, whereas the production costs have been dropping significantly in response to

17

the increasing range of applications. The recent studies and tests demonstrate that the improved

18

quality of the photodetectors is permitting much higher degree of ganging (passive or active),

19

thus significantly lowering the “per SiPM" readout costs. These technological trends are likely to

20

continue, thus allowing for a possible alternative concepts of the Photon Detectors, even within

21

the geometrical and cost confines of the baseline detectors.

22

One of the possible different concepts of the Photon Detector includes a long printed circuit board

23

with the overall dimensions identical to the light guide bars or ARAPUCA but with a simpler

24

construction involving only SiPMs distributed over the board surface. The SiPMs can be coated

25

with appropriate waveshifter (TPB or MSB) or a foil with the waveshifter in front of the SiPM

26

can be used to convert the VUV 128 nm Argon light to the blue light at the maximum detection

27

efficiency of the SiPM. The overall detection efficiency of such a “detector element"is expected to

28

be of the order of 25-30%, depending on the pixel size and the fill-factor of the SiPM. A photon

29

detector involving the SiPMs only would offer a major simplification of the construction and

30

integration efforts. Its overall performance can be reliably estimated and it is proportional to the

31

total area of the bar covered with the SiPMs. The performance of the baseline Photon Detectors

32

can be achieved with 2-4% of the area covered with the SiPMs. Taking 1800 cm2 as a bar surface

33

this coverage can be accomplished with 100-200 SiPMs of the standard 6x6 mm formfactor. With

34

12-fold passive ganging, successfully demonstrated in recent tests, such a solution would require

35

8-16 readout channels per bar. The multiplexing level is limited by the noise of the readout

36

electronics. Significantly higher degree of multiplexing can be achieved by use of larger pixel (like

37

75x75 microns) SiPMs and/or possible cold active ganging circuitry. Such a detector concept

38

appears very flexible and it would allows for future optimization in response to the expected

39

technological advances with no or minimal impact on the rest of the DUNE detector.

40

The Technical Proposal and TDR may include proposals to augment the capabilities of the photon

41

collector modules. In the case that the hardware requirements for such proposals would pose a

42

minimal impact on the detector design, additional R&D beyond the timescale of the TDR may be

43

required since it may impact the second 10 kt module if not the first. Some examples include:

44

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SLIDE 62

Chapter 6: Photon Detection System 6–45

TPB-Coated Reflector Foils (Szelc)

1

Xenon-Doped LAr (Escobar/Para)

2

TPB-Doped LAr (Escobar)

3

6.6.2 Photon Sensors

4

sec:fdsp-pd-ps

Content: (2 pages) - Zutshi

5

The SP DUNE Photon Detector System will use Silicon Photomultipliers, mated to the bar or

6

ARAPUCA photon collector options, to detect scintillation light generated in the LAr. Robust

7

photon detection efficiency, low operating voltages, small size and ruggedness make their usage

8

entirely plausible in the single phase design where the photon detectors are to be accommodated

9

inside the APA frames. The salient guiding principles of this SiPM-based photo-detection system

10

can be stated as:

11

Signal path separate from TPC readout. This implies cables dedicated to bringing the power in

12

and taking the analog or digitized signals from the PD system, out of the cryostat. Feed-through

13

cable space limitations therefore, imply some level of ganging of the SiPM signals inside the LAr

14

volume.

15

The optimal SiPM may depend on the photon collector option. Since all photon collector options

16

being currently considered involve shifting the 128 nm LAr scintillation to varying degrees, the

17

final fine-tuned choice may have to be made after the collector down-select. It should however be

18

kept in mind that the size of these effects, while not anything to sniff at, will not exceed 15-20 %.

19

The Silicon Photomultiplier packaging should allow for tileable arrays to be constructed to facilitate

20

high efficiency mating to the photon collectors and efficient space utilization inside the APA frame.

21

While understanding SiPM requirements (number of devices, dynamic range, triggering, zero-

22

suppression threshold etc.) in light of the physics goals is an ongoing process, it is clear from the

23

R&D carried out so far that devices from a number of vendors have the performance characteristics

24

in the vicinity of that needed for the DUNE photon detector system (see Table xxx). Furthermore,

25

a number and types of these devices are being installed in proto-DUNE which will provide an

26

excellent test bed for evaluating and monitoring SiPM performance in a realistic environment over

27

the medium term.

28

A key requirement, based on past experience, is ensuring the mechanical and electrical integrity

29

f these devices in a cryogenic environment. This is a DUNE requirement which catalog devices

30

from most vendors do not satisfy as they are only certified for operation down to -40C. Thus it

31

is of paramount importance for the DUNE PD Consortium to work with vendors in designing,

32

fabricating and certifying SiPM packaging that is robust and reliable from the point-of-view of

33

long-term operation in a cryogenic environment. Already there is interest from at least two vendors

34

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SLIDE 63

Chapter 6: Photon Detection System 6–46

(Hamamatsu and FBK) to engage with the Consortium in this fashion with the goal of having the

1

vendor warrantying the product for our application. Contact with other vendors and experiments

2

(e.g. DarkSide) is being pursued.

3

In parallel, comparative performance evaluation of promising SiPM candidates from multiple ven-

4

dors will need to be carried out. This evaluation will not only need to address inherent charac-

5

teristics (gain, dark rate, x-talk, after-pulsing etc) and ganging performance but also form factor,

6

spectral response and mating with regard to the multiple photon collector options. Experience ac-

7

quired from proto-DUNE construction and operation will inform QA/QC plans for the full detector

8

which will need to be delineated in detail.

9

6.6.3 Electronics

10

sec:fdsp-pd-pde

Content: (3 pages) - Moreno/Franchi/Djurcic

11

rjw: Include comment whether there are differences between the photon collector options

12

6.6.4 Quality Assurance

13

sec:fdsp-pd-qa

Content: (1 page) - Warner

14

6.7 Production and Assembly

15

sec:fdsp-pd-prod-assy

(Length: TDR=40 pages, TP=8 pages)

16

6.7.1 Photon Collectors Production

17

sec:fdsp-pd-prod-pc

Content: Cavanna/Whittington/Machado

18

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SLIDE 64

Chapter 6: Photon Detection System 6–47

Dip-Coated Light Guides (2 pages)

1

ssec:fdsp-pd-pc-prod-bar1

Double-Shift Light Guides (2 pages)

2

ssec:fdsp-pd-pc-prod-bar2

The production and assembly of the double-shift light guide modules is divided into separate

3

threads for the wavelength-shifting plates and the EJ-280 light guides. Many of the production,

4

quality assurance, and assembly procedures developed for the double-shift light guide design de-

5

ployed at ProtoDUNE-SP will remain the same for the DUNE single-phase far detector.

6

Manufacture of the WLS Plates Spray-coating of TPB on acrylic plates (see Fig.

fig:DoubleShiftLG-SprayedPlates

6.7).

7

Figure 6.7: TPB-coated acrylic plates after spraying at Indiana University during fabrication of parts for ProtoDUNE-SP.

fig:DoubleShiftLG-SprayedPlates

QA of the WLS Plates VUV conversion performance measured for neighboring samples from

8

the acrylic plate template using a vacuum-ultraviolet monochromator.

9

Receipt and QA of the Light Guides EJ-280 light guides fabricated by Eljen Technologies.

10

Received and scanned in a long dark-box using a blue LED (Fig.

fig:DoubleShiftLG-EJ280

6.8). Measure conversion and

11

transmission to the light guide ends to test attenuation. Direct transmission through the light

12

guide to confirm uniformity. Attenuation length in liquid argon shorter than in air, but long

13

attenuation in air has been shown to correspond to long attenuation in liquid argon.

14

Assembly of the Double-shift Light Guide Module Parts are shipped to the assembly point

15

where the EJ-280 light guide is mounted into the module frame and the WLS plates are attached.

16

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SLIDE 65

Chapter 6: Photon Detection System 6–48

Figure 6.8: EJ-280 light guide within darkbox for attenuation scan QA at Indiana University (prepared for ProtoDUNE-SP).

fig:DoubleShiftLG-EJ280

Figure 6.9: Mounting of the WLS plates to the EJ-280 bar.

fig:DoubleShiftLG-PlateMounting

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SLIDE 66

Chapter 6: Photon Detection System 6–49

ARAPUCA (2 pages)

1

ssec:fdsp-pd-pc-prod-arapuca

6.7.2 APA Frame Mounting Structure and Module Fixing

2

sec:fdsp-pd-assy-frames

Content: (2 pages) - Warner

3

Photon detector (PD) modules are inserted into the APA frames through ten slots (five on each

4

side of the APA frame) and are supported in place inside the frame in stainless steel guide channels.

5

The slot dimensions for the ProtoDUNE APA frames were 108.0mm X 19.2mm wide (See fig. 1).

6

The guide channels are pre-positioned into the APA frame prior to applying the wire shielding

7

mesh to the APA frames, and are not accessible following wire wrapping.

8

Insert Dave’s PD Mounting rails in APA frame mpicture

9

Following insertion, the PD modules are fixed in place in the APA frame using two stainless steel

10

captive screws, as shown in figure 2.

11

Insert Dave’s PD Mounting screws mpicture

12

Cryogenic thermal contraction

13

Bar-style PD modules are structurally composed of primarily polycarbonate and acrylic, which

14

have significantly different shrinkage factors compared to the stainless steel APA and PD support

15

frames (see table 1).

16

format table better?

17

tbl:fdsfpdshrink

Table 6.2: Shrinkage of Photon Detector Materials Material Shrinkage Factor (m/m) 206◦C Drop Stainless Steel (304) 2.7 × 10−3 FR-4 G-10 (In-plane) 2.1 × 10−3 Polystyrene (Average) 1.5 × 10−2 Acrylic and Polycarbonate (Average) 1.4 × 10−2 These differences in thermal expansion (or contraction in this case) were important to keep in mind

18

during design of the PD module supports. Mitigation for these varying contractions are detailed

19

in table 2:

20

Needs better table formatting?

21

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SLIDE 67

Chapter 6: Photon Detection System 6–50

tbl:fdsfpdshrinkeffects

Table 6.3: Relative Shrinkage of PD components and APA frame, and mitigations Interface Relative shrinkage Mitigation PD Length to APA width PD shrinks 25.7 mm Rel- ative to APA frame PD affixed only at one end of APA frame, free to contract at other end Width of PD in APA Slot PD shrinks 1.2 mm relative to slot width Photon detector not constrained in C-

channels. C channels and tolerances de-

signed to contain module across thermal contraction range Width of SiPM mount board (Hover board) to stainless steel frame Stainless frame shrinks 0.06 mm more than PCB Diameter of shoulder screws and FR-4 board clearance holes selected to allow for motion Width of SiPM mount board relative to polycarbonate mount block Polycarbonate block shrinks 1mm more than PCB Allowed for in clearance holes in SiPM mount board PD Mount Frame Deformation under static PD load

1

FEA modeling of the PD support structure was conducted to study static deflection prior to

2

building prototypes. Modeling was conducted in both the vertical orientation (APA upright,

3

as installed in cryostat) and also flat. Basic assumptions used were fully-supported fixed end

4

conditions for the rails, uniform loading of 3X PD mass (5 kg) along rails. Prototype testing

5

confirmed these calculations.

6

Insert Dave’s 4 deflection pictures here

7

Same for bars and ARAPUCAs

8

6.7.3 Photosensor Modules

9

sec:fdsp-pd-assy-psm

Content: (1 page) - Zutshi

10

The Silicon Photomultiplier analog signal will be ganged on the detector inside the LAr volume.

11

Passive and active ganging schemes are under consideration. Some passive ganging (sensors put

12

in parallel) schemes have been examined and are being installed inside proto-DUNE (see Fig.

13

yyy). The key point for parallel passive ganging in terms of maintaining signal-to-noise as devices

14

are ganged together is the terminal capacitance of the sensors. This characteristics can therefore

15

play an important in device selection or on the flip side in determining the maximum ganging

16

possible. In this scheme the ganged analog signals are then brought out via long cables ( 25 m) for

17

digitization outside the cryostat. This is currently being done in proto-DUNE using teflon ethernet

18

CAT6 cables.

19

An interesting alternative option that may provide more flexibility in terms of the level of photo-

20

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SLIDE 68

Chapter 6: Photon Detection System 6–51

sensor ganging possible and also obviate the need for carrying analog signals of long cables is the

1

so-called active ganging option where the amplifiers and ADCs sit on the board carrying the pho-

2

tosensors inside the LAr volume. This option however brings, in all the reliability and long-term

3

stability issues related to cold electronics into play. While active ganging prototypes are under

4

study the design cannot be considered to be at a mature stage at this point and schedule and

5

technical considerations may influence how far this promising option can be pursued.

6

In any case, the SiPMs will need to be surface-mounted on a PCB that can mate efficiently with

7

the photon collector options. proto-DUNE will provide a wealth of operational experience and

8

information on such a design with atleast a passive ganging board. It is already clear, however,

9

that some R&D is needed in optimizing the connectors to be used to couple the cable to the board

10

and understanding the mechanical stresses involved in the SiPM-PCB-Connector system (with a

11

varying CTEs) as it is cooled (or cycled) to cryogenic temperatures.

12

Just cold boards?

13

6.7.4 Assembly Procedures

14

sec:fdsp-pd-assy-ap

Content: Cavanna/Whittington/Machado

15

PC assembly modules (ready for APA installation).

16

Can we have a single section that describes how the bars and/or ARAPUCA are assembled into PC modules or do we need a separate subsub(!)section for each?

17

Dip-Coated Light Guide Modules (2 pages)

18

ssec:fdsp-pd-pc-assy-bar1

Double-Shift Light Guide Modules (2 pages)

19

ssec:fdsp-pd-pc-assy-bar2

ARAPUCA Modules (2 pages)

20

ssec:fdsp-pd-pc-assy-arapuca

6.7.5 Electronics

21

sec:fdsp-pd-assy-pde

Content: (2 pages) Moreno/Franchi/Djurcic

22

Components

23

Boards

24

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SLIDE 69

Chapter 6: Photon Detection System 6–52

Cable plant

1

6.7.6 QA

2

sec:fdsp-pd-assy-qa

Content: (2 pages) - Warner

3

Sub-assemblies- same for all modules.

4

Completed modules- largely same for different option, at least for TP.

5

6.8 System Interfaces

6

sec:fdsp-pd-intfc

Content: Kemp

7

(Length: TDR=10 pages, TP=2 pages)

8

Include an image of each interface in appropriate section.

9

This section describes the interface between the DUNE SP Far Detector Photon-Detection System

10

(SP-PDS) and several other consortia, task forces (TF) and subsystems listed below, namely:

11

1. Anode Plane Assembly (APA)

12

2. Feedthroughs

13

3. Cold Electronics (CE)

14

4. Cathode Plane Assembly (CPA) / High Voltage System (HVS): Reflector foils (light en-

15

hancement)

16

5. Data Acquisition (DAQ)

17

6. Calibration / Monitoring

18

The contents of the section are focused on the needs to complete the design, fabrication, installation

19

f the related subsystems, and are organized by the elements of the scope of each subsystem at

20

the interface between them.

21

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 70

Chapter 6: Photon Detection System 6–53

6.8.1 Anode Plane Assembly

1

sec:fdsp-pd-intfc-apa

The PDS is integrated in the APA frame to form a single unit for the detection of both ionization

2

charge and scintillation light.

3

Hardware: The hardware interface between APA and PDS has two main components:

4

1. Mechanical: a) supports for the PDS detectors; b) access slots for installation of the detectors,

5

if, as in the present baseline design, the detectors will be installed after the wire winding is

6

completed; c) access slots for the cabling of the PDS detectors; d) routing of the PDS cables

7

inside the side beams of the APA frame.

8

2. Electrical: grounding scheme and electrical insulation, to be defined together with the CE

9

consortium, given the CE strict requirements on noise.

10

Design: Since the design of the PDS detectors is still under evolution, the APA consortium will

11

evaluate different solutions proposed by the PDS consortium that may require modifications of the

12

structure of the APA frame. The evaluation phase is expected to be concluded by Spring 2018.

13

The PDS consortium will provide detailed engineering drawings of the detectors and specifications

14

n the size and number of cables, and of any connectors required. If the PDS detectors will be

15

installed after the wire winding is completed, as in the present baseline design, the APA consortium

16

will evaluate possible variations of the baseline geometry, as suggested by the PDS consortium:

17

larger slot dimensions and increased number of slots. If photon detectors are installed in the

18

APA frame prior to the winding, the PDS consortium is responsible for designing the supports

19

inside the APA frame and providing a protection for the detectors against UV light. The APA

20

consortium will evaluate the proposed design. The APA consortium, together with the CE and

21

PDS consortia, will revisit the requirements on the mesh pitch and wire size, and set specifications

22

for the mesh procurement, compatibly with the availability on the market. The APA consortium

23

will evaluate the feasibility of routing the PDS detector cables inside the side beams of the APA

24

frame, considering also the cabling needs of the Cold Electronics consortium. This may require

25

the evaluation of side beams of larger dimensions.

26

Production: The APA Consortium fabricates all APA-PDS mechanical interface hardware. The

27

PDS consortium fabricates all PDS detectors and electronic boards, and will provide all cables and

28

connectors.

29

Testing: The interface hardware and the interconnect procedures between APA and PDS, in-

30

cluding cabling, are validated at one or more integration/installation trials at an integration test

31

facility. The APA and PDS consortia will be responsible for the procurement of their respective

32

hardware and delivery to the integration test facility. Experts from both groups work with the

33

installation team to perform trial fit and cabling before the final design is completed. Electrical

34

test will be performed with a APA/PDS/CE vertical slice test if available.

35

Commissioning: The PDS consortium will provide procedures and personnel for the commis-

36

sioning of the PDS components. The APA consortium will be responsible for applying the bias

37

voltages on the wire planes.

38

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SLIDE 71

Chapter 6: Photon Detection System 6–54

6.8.2 Feedthroughs

1

sec:fdsp-pd-intfc-feed

6.8.3 Cold Electronics (CE)

2

sec:fdsp-pd-intfc-feed

Hardware: The hardware interfaces between the CE and PDS occur on the chimneys and in the

3

racks mounted on the top of the cryostat which house low and high voltage power supplies for PDS,

4

low and bias voltage power supplies for CE, as well as equipment for the Slow Control and Cryo

5

Instrumentation (SC in the following), and possibly DAQ consortia. There should be no electrical

6

contact between the PDS and CE components except for sharing a common reference voltage point

7

(ground) at the chimneys. An additional indirect hardware interface takes place inside the cryostat

8

where the CE and PDS components are both installed on the APA (responsibility of the single

9

phase far detector APA consortium, APA in the following), with cables for CE and PDS that may

10

be physically located in the same space in the APA frame, and where the cables and fibers for CE

11

and PDS may share the same trays on the top of the cryostat (these trays are the responsibility

12

f the facility and the installation of cables and fibers will follow procedures to be agreed upon in

13

consultation with the underground installation team, UIT in the following).

14

Chimneys: in the current design CE and PDS use separate flanges for the cold/warm transition

15

and each consortium is responsible for the design, procurement, testing, and installation, of their

16

flange on the chimney, together with the LBN facility that is responsible for the design of the

17

cryostat. Racks on top of the cryostat: the installation of the racks on top of the cryostat is

18

a responsibility of the facility, but the exact arrangement of the various crates inside the racks

19

will be reached after common agreement between the CE, PDS, SC, and possibly DAQ consortia.

20

The PDS and CE consortia will retain all responsibilities for the selection, procurement, testing,

21

and installation of their respective racks, unless for space and cost considerations an agreement is

22

reached where common crates are used to house low voltage or high/bias voltage modules for both

23

PDS and CE. Even if both CE and PDS plan to use floating power supplies, the consequences of

24

such a choice on possible cross-talk between the systems needs to be studied. Electrical contacts

25

between PDS and CE components: there should be no electrical contact between the CE and

26

PDS components, neither inside nor outside the cryostat, with the exception of the use of the

27

same reference voltage (grounding) on the chimneys, with each of the CE and PDS has a separate

28

connection to the detector ground (the cryostat).

29

Software: there are no direct interfaces between the CE and PDS systems. Test stands and inte-

30

gration facilities: various test stands and integration facilities will be developed. In all cases the CE

31

and PDS consortia will be responsible for the procurement, installation, and initial commissioning

32

f their respective hardware in these common test stands. The main purpose of these test stands

33

is study the possibility that one system may induce noise on the other, and the measures to be

34

taken to minimize this cross-talk. For these purposes, it is desirable to repeat noise measurements

35

whenever new, modified detector components are available for one or the other consortium. This

36

requires that the CE and PDS consortia agree on a common set of tests to be performed and that

37

the CE consortium can operate the PDS detectors within a pre-determined range of operating

38

parameters, and vice versa, without the need of providing personnel from the PDS consortium

39

when the CE consortium is performing tests or vice versa. Procedures should be set in place to

40

decide the time allocation to tests of the components of one or the other consortium.

41

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 72

Chapter 6: Photon Detection System 6–55

Installation: the installation of the cables for the CE and PDS requires coordination with the

1

APA consortium and the UIT. This applies both for the routing of the CE and PDS cables through

2

the APA frames while the APAs are hanging in the âĂĲtoasterâĂİ, and later, after the APA has

3

been moved inside the cryostat, for the routing of the cables in the trays hanging from the top

4

f the cryostat. The CE consortium will retain the responsibility for the CE cables, and similarly

5

for the PDS consortium, but the possibility that the CE and PDS cables may need to be routed

6

together through the APA frames, may require that the two installation teams cooperate for this

7

task.

8

6.8.4 Cathode Plane Assembly (CPA) / High Voltage System (HVS): Re-

9

flector foils (light enhancement)

10

sec:fdsp-pd-intfc-le

This section describes the interface between the light collection boosting system of the SP-PDS and

11

the HVS. These systems interact in the case that the photon detection system includes wavelength-

12

shifting reflector foils mounted on the CPA.

13

Hardware: The purpose of installing the wavelength-shifting (WLS) foils is to allow enhanced

14

detection of light from events near to the cathode plane of the detector. The WLS foils consist of

15

a wavelength shifting material (likely tetraphenyl butadiene - TPB) coated on a reflective backing

16

material. The foils would be mounted on the surface of the cathode plane array (CPA) in order to

17

enhance light collection from events occurring nearer to the CPA, and thus greatly enhancing the

18

spatial uniformity of the light collection system as detected at the APA mounted light sensors. The

19

foils may be laminated on top of the resistive kapton surface of the CPA frames, with the option

20

f using metal fasteners/tacks that would also serve to define the field lines. Production of the

21

FR4+resistive kapton CPA frames are the responsibility of the HV consortium. Production and

22

TPB coating of the WLS foils will be the responsibility of the Photon Detection consortium. The

23

fixing procedure for applying the WLS foils onto the CPA frames and any required hardware will

24

be the responsibility of the Photon Detection consortium, with the understanding that all designs

25

and procedures will be pre-approved by the HV consortium. This new detector component is not

26

being tested in ProtoDUNE, however its integration in the present DUNE far detector HV system

27

could possibly imply performance and stability degradation (due for example to ion accumulation

28

at the CPA surface); the assembly procedure of the CPA/FC module could become more complex

29

due to the presence of delicate WLS foils. Intense R&D will be required before deciding on its

30

implementation.

31

R&D studies: It will be the responsibility of the HV consortium to define testing requirements

32

that will need to be carried out in order to verify that the proposed WLS foil installation will not

33

degrade the performance of the CPA. It will be the responsibility of the PD consortium to carry

34

ut these tests.

35

Integration: An integration test stand will likely be employed to verify the proper operation of

36

the CPA panels with the addition of WLS foils under high voltage conditions. Light performance

37

(wavelength conversion and reflectivity efficiency) will also be verified. The HV consortium will

38

be responsible for HV aspects of the test stand and the PD consortium will be responsible for the

39

light performance aspects.

40

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SLIDE 73

Chapter 6: Photon Detection System 6–56

Installation: The wavelength shifting material (TPB) can degrade under certain environmental

1

conditions, so its addition to the surface of the CPAs will increase the handling requirements

2

during installation. The PD consortia will be responsible for defining the environmental and

3

handling procedures that will ensure minimal degradation of the WLS foil performance. The PD

4

consortium will be responsible for the installation of the WLS foils onto the CPA panels. The HV

5

consortium will be responsible for all other aspects of the installation of the CPA panels.

6

Commissioning: PD and HV consortia will provide staffing for commissioning the CPAs in the

7

cryostat in the following manner...

8

6.8.5 DAQ

9

sec:fdsp-pd-intfc-daq

Data Physical Links: Data are passed from the PDS to the DAQ on optical links conforming

10

to an IEEE Ethernet standard. The links run from the PDS readout system on the cryostat to

11

the DAQ system in the Central Utilities Cavern (CUC).

12

Data Format: Data are encoded using a data format based on UDP/IP. The data format is

13

derived from the one used by the Dual Phase TPC readout. Details will be finalized by the time

14

f the DAQ TDR.

15

Data Timing: The data shall contain enough information to identify the time at which it was

16

taken.

17

Data Volume: The DAQ will have provision to receive up to 8GBit/s of data from the PDS per

18

APA.

19

Data Link Speed: The PDS data for each APA may be transmitted either on multiple links

20

following the 1000Base-SX standard or a single link following the 10GBase-SR standard. In either

21

case the fibre will be chosen to give sufficient margin for the distance from the cryostat to the

22

CUC. Details will be finalized by the time of the DAQ TDR.

23

Trigger Information: The PDS may provide summary information useful for data selection. If

24

present, this will be passed to the DAQ on the same physical links as the remaining data.

25

Timing and Synchronization: Clock and synchronization messages will be propagated from the

26

DAQ to the PDS using a backwards compatible development of the ProtoDUNE Timing System

27

protocol ( See Dune docdb-1651 ). There will be at least one timing fibre available for each data

28

links coming from the PDS. Power-on initialization and Start of Run setup: The PDS may require

29

initialization and setup on power-on and start of run. Power on initialization should not require

30

communication with the DAQ. Start run/stop run and synchronization signals such as accelerator

31

spill information will be passed by the timing system interface.

32

Local Monitoring: The PDS may require network connections for local monitoring and debug-

33

ging. These are the responsibility of the PDS.

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Chapter 6: Photon Detection System 6–57

Software: There should be no software required for the PDS to DAQ interface. The definition of

1

the data format should provide the required information.

2

Interaction with other groups: Related interface documents describe the interface between

3

the CE and LBNF, DAQ and LBNF, DAQ and Photon and both DAQ and CE with Technical

4

Coordination. The cryostat penetrations including through-pipes, flanges, warm interface crates

5

and feedthroughs and associated power and cooling are described in the LBNF/PDS interface doc-

6

ument. The rack, computers, space in the CUC and associated power and cooling are described in

7

the LBNF/DAQ interface document. Any cables associated with photon system data or commu-

8

nications are described in the DAQ/Photon interface document. Any cable trays or conduits to

9

hold the DAQ/CE cables are described in the LBNF/Technical Coordination interface documents

10

and currently assumed to be the responsibility of Technical Coordination.

11

Integration: Various integration facilities are likely to be employed, including vertical slice tests

12

stands, PDS test stands, DAQ test stands and system integration/assembly sites. The DAQ con-

13

sortia will provide hardware and software for a âĂĲvertical slice testâĂİ The PDS consortia will

14

provide PDS emulators and PDS readout hardware for DAQ test stands. (The PDS emulator and

15

PDS readout hardware may be the same physical object with different configuration ). Responsi-

16

bility for supply and installation of DAQ/PDS cables in these tests will be defined by the time of

17

the DAQ TDR.

18

Installation: Responsibility for purchase of the DAQ/CE cables is assigned to the PDS. The

19

installation of the DAQ/CE cables is assigned to the PDS.

20

6.8.6 Calibration / Monitoring

21

sec:fdsp-pd-intfc-calib

This subsection concentrates on the description of the interface between the SP-PDS and Cali-

22

bration/Monitoring Task Force (CTF), since there is are components of the system planned to be

23

installed with the HVS Cathode, and through Field Cage strips and File Cage ground plane.

24

Hardware: The SP-PDS has proposed the photon-detector gain and timing calibration system to

25

be also used for SP-PDS monitoring purposes during commissioning and experimental operation. A

26

pulsed UV-light system is proposed to cross-calibrate and monitor the DUNE-SP photon detectors.

27

The hardware consists of warm and cold components. By placing light sources and diffusers on the

28

cathode planes designed to illuminate the anode planes the photon detectors embedded in the anode

29

planes can be illuminated. Cold component (diffusers and fibers) interface with High-Voltage and

30

will be described in a separate interface document. Warm components include controlled pulsed-

31

UV source and warm optics. These warm components will interface CTF with Slow-Controls/DAQ

32

subsystems and will be described in corresponding documents. Optical feedthrough is the cryostat

33

interface. Hardware components will be designed and fabricated by SP-PDS. Other aspects of

34

hardware interfaces are described in the following. The CTF and PDS groups might share rack

35

spaces which needs to be coordinated between both groups. There wonâĂŹt be dedicated ports for

36

all calibration devices. Therefore, multi-purpose ports are planned to be shared between various

37

groups. CTF and SP-PDS will define ports for deployment. It is possible that SP-PDS might

38

use Detector Support Structure (DSS) ports or TPC signal ports for routing fibers. The CTF in

39

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Chapter 6: Photon Detection System 6–58

coordination with other groups will provide a scheme for interlock mechanism of operating various

1

calibration devices (e.g. Laser, radioactive sources) that will not be damaging to the PDS. The

2

PDS has proposed the photon-detector gain and timing calibration system. The system will be used

3

for PDS monitoring purposes during commissioning and for standard experimental operation. A

4

pulsed UV-light system is proposed to cross-calibrate and monitor the DUNE-SP photon detectors.

5

The hardware consists of warm and cold components. By placing light sources with diffusers on

6

the cathode planes, the system is designed to illuminate the photon detectors embedded in the

7

anode planes. The details are described in the DUNE Interface Document: SP-PDS/CTF. Cold

8

components of the calibration system (diffusers and fibers) interface with the HVS. Diffusers are

9

installed at CPA, and therefore reside at the same CPA potential. Quartz fibers are insulators used

10

to transport light from optical feedthroughs (at the cryostat top) through Filed Cage ground plane,

11

and through Filed Cage strips to the CPA top frame. These fibers are then optically connected

12

to diffusers located at CPA panels. Required fiber resistance is defined by HVS requirements

13

to ensure the cathode is protected from shorting out due to fiber conductivity. PDS hardware

14

components will be designed and fabricated by PDS.

15

Firmware: The firmware will enable UV-light system to interface to DAQ/Slow-Controls to com-

16

municate start/stop of calibration run, and issue commands to define types (amplitude, timing,

17

frequency) of calibration pulses. Protocols will be defined with DAQ, but the firmware realization

18

and testing will be responsibility of SP-PDS. Timing and Synchronization: Clock and synchroniza-

19

tion messages will be propagated from the DAQ to the SP-PDS calibration unit using a backwards

20

compatible development of the ProtoDUNE Timing System protocol (See Dune docdb-1651). See

21

also SP-PDS to DAQ interface definition.

22

Software: The software interface between the groups consists of software needed to perform

23

calibrations of the photon detection system and any simulations of the detector needed to develop

24

calibration schemes. The calibration software which will analyze the photon detection input and

25

calculate calibration quantities will be the responsibility of the SP-PDS Consortium, with the

26

guidance of the CTF. The CTF will be responsible for defining the quantities to be measured. The

27

SP-PDS Consortium will be responsible for providing a simulation model to test the calibration

28

schemes. The CTF will provide the design and model of databases (DBs) to store the calibration

29

information and these DBs will be filled out by the SP-PDS Consortium.

30

Testing: Components of such system are being rested with ProtoDUNE. Additional tests will be

31

managed between SP-PDS and CTF if necessary, including a test stand with shared responsibility.

32

Integration: Various integration facilities are likely to be employed, including vertical slice tests

33

stands, cold electronics test stands, DAQ test stands and system integration/assembly sites. The

34

PDS consortia will provide firmware/software for PDS integration and operation and testing.

35

Components of such system are being rested with ProtoDUNE. Additional tests will be managed

36

between PDS and HVS if necessary, including a test stand with shared responsibility. HVS will

37

verify HV design and operation without discharges that could cause light emission observed by

38

PDS should this be a concern.

39

Integration: Various integration facilities are likely to be employed, including vertical slice tests

40

stands, cold electronics test stands, DAQ test stands and system integration/assembly sites. The

41

PDS consortia will provide support for PDS integration and operation.

42

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Chapter 6: Photon Detection System 6–59

Installation: Responsibility for fabrication/installation of PDS Calibration components is as-

1

signed to PDS. Responsibility for fabrication/installation of PDS Calibration components is as-

2

signed to PDS.

3

Commissioning: PDS-SP will provide staffing for commissioning of SP-PDS calibration system

4

in the cryostat. Cold PDS-SP components need be installed with Cathode-Plane assemblies and

5

Field Cage arrays, and possible with DSS. Warm SP-PDS calibration components may be installed

6

at the end and tested with DAQ. Calibration scope and goals will be further defined within CTF.

7

PDS will provide staffing for commissioning of PDS calibration system in the cryostat.

8

6.9 Installation, Integration, and Commissioning

9

6.9.1 Transport and Handling

10

Following assembly and testing of the PD modules they need to be carefully packaged and shipped

11

to the far detector site for checkout and any final testing prior to installation into the cryostat.

12

Handling and shipping procedures will depend on the environmental requirements determined for

13

the photon detectors.

14

Development of a testing plan to determine environmental requirements for photon detector

15

handling and shipping. The environmental conditions apply for both surface and under-

16

ground transport, storage and handling. Requirements for light (UV filtered areas), temper-

17

ature, and humidity exposure should be developed.

18

Handling procedures need to be developed to ensure environmental requirements are met.

19

This should include handling at all stages of component and system production and assembly,

20

testing, shipping, and storage. It is likely that PD modules and components will be stored for

21

periods of time during production and prior to installation into the FD cryostats. Appropriate

22

storage facilities need to be constructed at locations where storage will take place.

23

Shipping and storage containers need to be designed and produced. Given the large number

24

f photon detector modules to be installed in the FD, it will be advantageous to develop

25

shipping containers that can be re-used.

26

Documentation and tracking of all components and PD modules will be required during

27

the full production and installation schedule. Well defined procedures need to be in place

28

to ensure that all components/modules are tested and examined prior to, and after, ship-

29

ping. Information coming from such testing and examinations will be stored in a hardware

30

database.

31

It is expected that photon detector will be assembled at more than one location and that

32

components will come from a number of other locations. Oversight of the shipping and

33

handling procedures will be critical. This responsibility should fall to a single institution and

34

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Chapter 6: Photon Detection System 6–60

manager.

1

Integration and Test Facility (ITF) Operations:

2

– Transportation to and from ITF should be planned. The PDS units will be shipped

3

from the production area in quantities compatible with the APA transport rates.

4

– Operations: The PDS deliveries will be stored in temperature and humidity controlled

5

storage area. Their mechanical status will be inspected.

6

Transportation to SURF: The delivery to SURF will be such that the storage time before

7

integration will be at most two weeks.

8

6.9.2 Integration with APA

9

Integration:

10

If the PDS detectors can be installed after the wire winding is completed, as in the present

11

baseline design, their integration on the APA frame will happen at the Integration facility.

12

Experts from both groups will work with the installation team. An electrical test with

13

APA/PDS/CE will be performed at the integration facility in a cold box, after the integration

14

f PDS and CE on the APA frame has been completed.

15

Installation:

16

The APA consortium will be responsible for the transportation of the integrated APA frames

17

from the integration facility to the LBNF/SURF facility. The UIT team, under supervision

18

f the APA group, will be responsible to move the equipment into the clean room. Work on

19

the 2-APA connection and inspection in the toaster is performed by the APA group. Work

20

n cabling in the toaster is performed by PDS and CE groups under supervision of the APA

21

group. Once the APAs will be moved inside the cryostat, the PDS and CE consortia will be

22

responsible for the routing of the cables in the trays hanging from the top of the cryostat.

23

6.9.3 Installation into Cryostat / Cabling

24

6.9.4 Calibration and Monitoring

25

The calibration and monitoring systems for the photon detector system will interface with several

26

groups within the DUNE FD project, including the calibration group, slow controls group, and

27

data acquisition group.

28

The number of penetrations required for the calibration and monitoring systems need to be

29

determined so that the cryostat design, including feedthroughs can be finalized.

30

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Chapter 6: Photon Detection System 6–61

Mounting requirements for the calibration system inside the cryostat need to be determined.

1

Any light delivery hardware to be mounted on the cathode plane assemblies will need to

2

be developed in coordination with the CPA group. A plan for fiber routing will need to be

3

made. Cable routing and power distribution plans for both the calibration and monitoring

4

Readout of both the calibration and monitoring systems will need to be developed with the

5

DAQ and slow controls groups. Mappings of the systems will need to be reflected in the PD

6

hardware database.

7

Any calibration systems utilizing radioactive sources will need to be developed in coordination

8

with the radiopurity and physics groups. It is important to ensure in addition, that any

9

components of such a system do not contaminate the LAr or compromise the electron lifetime.

10

6.10 Installation, Integration and Commissioning

11

sec:fdsp-pd-install

Content: Kemp

12

(Length: TDR=30 pages, TP=6 pages)

13

6.10.1 Transport and Handling (1 page)

14

sec:fdsp-pd-install-transport

6.10.2 Integration with APA (2 pages)

15

sec:fdsp-pd-install-pd-apa

6.10.3 Installation into cryostat/cabling (1 pages)

16

sec:fdsp-pd-install-pd-cryo

6.10.4 Calibration/Monitoring (1 pages)

17

sec:fdsp-pd-install-calib

6.11 Quality Control

18

sec:fdsp-pd-qc

Content: Warner

19

(Length: TDR=10 pages, TP=2 pages)

20

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Chapter 6: Photon Detection System 6–62

6.11.1 Production and Assembly (Local)

1

sec:fdsp-pd-qc-local

6.11.2 Post-factory Installation (Remote)

2

sec:fdsp-pd-qc-remote

6.12 Safety

3

sec:fdsp-pd-safety

Content: Warner

4

(Length: TDR=5 pages, TP=1 pages)

5

6.13 Organization

6

sec:fdsp-pd-org

Content: Segreto/Warner/Mualem

7

(Length: TDR=20 pages, TP=4 pages)

8

6.13.1 Single-Phase Photon Detection System Consortium Organization

9

sec:fdsp-pd-org-consortium

Content: Segreto

10

6.13.2 Planning Assumptions

11

sec:fdsp-pd-org-assmp

Content: Segreto/Warner

12

6.13.3 WBS and Responsibilities

13

sec:fdsp-pd-org-wbs

Content: Warner/Mualem

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Chapter 6: Photon Detection System 6–63

6.13.4 High-level Cost and Schedule

1

sec:fdsp-pd-org-cs

Content: Warner/Mualem

2

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SLIDE 81

Chapter 7: Data Acquisition System 7–64

Chapter 7

1

Data Acquisition System

2

ch:fdsp-daq

7.1 Data Acquisition System (DAQ) Overview (Georgia Kara-

3

giorgi & David Newbold)

4

sec:fdsp-daq-ov

2 Pages - largely generic but some highlighting of SP-specifics.

5

7.1.1 Introduction

6

sec:fdsp-daq-intro

The overall DUNE Far Detector Data Acquisition System (DAQ) is illustrated in Fig.

fig:daq-overview

7.1.

7

Describe figure here.

8

Figure.

fig:daq-overview

7.1 illustrates the data flow and the exchange of trigger and monitoring messages.

9

7.1.2 Design Considerations

10

sec:fdsp-daq-des-consid

Include: Raw data rate from WIBs, Josh’s table of data volumes for each event type and the 30 PB/year offline limit. Space and thermal power limits. Note, this table may be better put into Section

sec:fdsp-daq-design

7.2 to make this section more generic.

11

The Data Acquisition System design must enable... ...

12

Anne suggests: Within this section add ref to requirements document when it’s ready, and maybe list the most important half dozen in a table here). E.g.,

13

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SLIDE 82

Chapter 7: Data Acquisition System 7–65

Detector Module #N DUNE FD DAQ DAQ Module #N Front-End Readout Front-End Computing Back-End Computing

Electronics Electronics Readout HW Data Receiver RAM Buffer

Data

Module Trigger Logic

L0 triggers primitives

Data Selector Event Builder Farm

trigger commands

Global Trigger Logic Output Disk Buffer

Figure 7.1: A generalized overview of high-level far detector DAQ components showing one out of the four detector modules. The electronics digitizes the detector signals and send the data to the DAQ Front-End Readout Hardware. This component forms L0 Trigger Primitives and sends them and the data to a Front-End Computing Data Receiver. The receiver sends the data to a RAM of sufficient size to buffer it longer than typical worse case trigger latency. The L0 Trigger Primitives are forward to the Module Trigger Logic (MTL) unit which services the entire detector module. The MTL forwards to the Global Trigger Logic unit which services the entire DUNE Far Detector. Trigger commands are then sent back down and to the Event Builder Farm which, based on the trigger command information, queries the appropriate Front-End Computing units which return the requested data. The Event Builder then aggregates the data and writes it to the Output Disk Buffer. Each 10 kt module has specific differing details which are described below.

fig:daq-overview

Table 7.1: Important requirements on the DAQ system design Requirement ...

pdphysicsparams

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SLIDE 83

Chapter 7: Data Acquisition System 7–66

By the end of the volume, for every requirement listed in this section, there should exist an explanation of how it will be satisfied.

1

7.1.3 Scope

2

sec:fdsp-daq-scope

This section may also wish to refer to Fig.

fig:daq-overview

7.1.

3

The scope of the Data Acquisition System includes the continued procurement of materials for,

4

and the fabrication, testing, delivery and installation of the following systems:

5

Whatever the items are...

6

Readout electronics

7

8

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SLIDE 84

Chapter 7: Data Acquisition System 7–67

7.2 DAQ Design

1

sec:fdsp-daq-design

16 Pages

2

7.2.1 Overview (Giles Barr)

3

sec:fdsp-daq-ltr

The DAQ Design has been driven by finding a cost effective solution that satisfies the requirements.

4

Seveal design choices have nevertheless been made. From a hardware perspecive, the DAQ design

5

follows a standard HEP experiment design, with customised hardware at the upstream, feeding

6

and funnelling (merging) and moving the data into comupters. Once the data and triggering

7

information are in computers, a considerable degree of flexibility is available and the processing

8

proceeds with a pipelined sequence of software operations, involving both parallel processing on

9

multi-core computers and switched networks. The flexibility allows the procurement of computers

10

and networking to be done late in the delivery cycle of the DUNE detectors, to benefit from

11

increased capability of commercial devices and falling prices.

12

Since DUNE will operate over a number of decades, the DAQ has been designed with upgradability

13

in mind. With the fall in cost of serial links, a guiding principle is to include enough output

14

bandwidth to allow all the data to be passed downstream of the custom hardware. This allows

15

the possibility for a future very-fast farm of comuting elements to accomodate new ideas in how

16

to collect the DUNE data. The high output bandwidth also gives a risk mitigation path in case

17

the noise levels in a part of the detector are higher than specified and higher than tolerable by

18

the baseline trigger decision mechanism; it will allow aditional data processing to be added (at

19

additional cost).

20

The data collection will incorporate the data from single-phase and dual-phase TPCs and also single

21

and dual-phase versions of the photon-detector readout system. These are viewed as essentially

22

four types of sub-detectors within the DAQ and will follow the same overall data collection scheme

23

as shown in figure 1. The readout is arranged in a hierarchical manner to allow localised trigger

24

decisions to be made at the APA level, and then the cavern level before being combined over the

25

full four caverns. ch initial trigger decisions. The control of the detector elements will allow a fault

26

in one part to not halt data taking in another part, certainly at the per-cavern level, but maybe

27

also at more local levels. This will prevent a supernova burst following a failure in some part of a

28

cavern from being missed.

29

[The folowing text will need considerable revision to make sure it corresponds with whatever ends

30

up as figure 1, but the text here gives an idea that the overview will be a very quick visit of

31

everything, and all the detail is in the later sections. Terms in boldface are temporary madeup

32

things and must be replaced by the officially decided names].

33

It is helpful, on first looking at the DUNE DAQ dataflow scheme, to consider how the main data is

34

collected first and then to look at how the triggering and synchronisation functions are included;

35

we take this approach in this overview. The main data are initially merged within one APA and

36

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SLIDE 85

Chapter 7: Data Acquisition System 7–68

placed in a primary buffer to allow triggering decisions to be made. When a trigger decision is

1

made, all the data in a time window and in a designated region of interest (ROI) around the trigger

2

is extracted from the buffer and sent for event building, a second buffer area and possible transfer

3

to permanent storage at Fermilab. This covers trigger decisions for beam, calibation, atmospheric

4

neutrino, cosmic ray events, individual supernova neutrinos and also candidates for searches such

5

as proton decays, or low energy events such as solar and diffuse supernova neutrinos. Additionally,

6

when a supernova burst is detected internally within DUNE, a further SSD buffer will be used

7

to store all the data for all APAs for a long period. The primary buffer must be long enough for

8

trigger decision latency (including the time for enough supernova events in a burst to arrive and

9

appear over the background). Further details of the buffering scheme is described in section 7.2.2.

10

(Triggering Overview) In parallel with the data buffering scheme described above, summaries

11

f detected hits trigger primitives are assembled at the APA level to detect clusters of hits and

12

apply algorithms to distingush them from background (either radioactive decays or detector noise).

13

This is described in detail in section 7.2.3. Whether this process is more suitable for FPGAs

14

r computers is under study, as it depends on the interfaces, both can be accomodated in the

15

architecture, and both have been costed (neither yet!). To retain the APA-level modulariy, the

16

trigger primitives are collected and processed in the same APA node that buffers the data. The

17

trigger primitives are then sent to the cavern level and then the detector-level triggers to allow

18

both multi-APA triggers to be formed and also allow the supernova burst detection decisions to be

19

made to initate data transfer to SSDs. This is described in detail in section 7.2.5. When a trigger

20

decision is formed, instructions are sent to the primary buffers to retrieve the full data, build

21

them into events and store the results in the secondary buffers. The events for the main physics

22

analyses will be retained for offline study at this point in the DAQ. A software trigger algorithm

23

could be run at this point to eliminate obvious noise-source events (such as pickup on a row of

24

wires), especially if numerous. A further feature, useful for certain supernova studies will be to let

25

a sample of below-threshold events through to the secondary buffers where they are retained for a

26

few hours. If a SNEWS external warning of supernova is subsequently received, these events can

27

be kept permanently if desired, to allow lower thresholds during a SNEWS period than normal.

28

(Synchronisation Overview) Unknown until the interface with elecronics is known

29

7.2.2 Local Readout & Buffering (Giles Barr & Giovanna Miotto & Brett

30

Viren)

31

sec:fdsp-daq-ltr

Describe how the data is received from the detector electronics, and buffered while awaiting a trigger decision, together with any processing that affects stored data. The starting point is data incoming from the WIBs and the end point is corresponding data sitting in memory ready for event building.

32

Figure

fig:daq-readout-buffering-baseline

7.2 illustrates the local readout and buffering data flow in the context of a single APA.

33

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SLIDE 86

Chapter 7: Data Acquisition System 7–69

Single-Phase Module -- two APAs Cold Electronics APA 2 APA 1 Single-Phase Module DAQ Single-Phase Module DAQ Components for two APAs Front-End Readout for two APAs ACTA COB 2 ACTA COB 1 Front-End Computing for two APAs FELIX Host Computer Single-Phase Module Back-end Computing

WIB1 connectors [1] [2] [3] [4] RCE1 FPGA SSD RCE2 FPGA SSD RCE3 FPGA SSD RCE4 FPGA SSD WIB2 connectors [1] [2] [3] [4] WIB3 connectors [1] [2] [3] [4] WIB4 connectors [1] [2] [3] [4] WIB5 connectors [1] [2] [3] [4] WIB1 connectors [1] [2] [3] [4] RCE1 FPGA SSD RCE2 FPGA SSD RCE3 FPGA SSD RCE4 FPGA SSD WIB2 connectors [1] [2] [3] [4] WIB3 connectors [1] [2] [3] [4] WIB4 connectors [1] [2] [3] [4] WIB5 connectors [1] [2] [3] [4] FELIX PCIe board SNB dump Event Builder RAM Buffer Module Trigger Logic

L0 trigger primitives

Data Selector Event Builder Offline Disk Buffer

SNB-dump trigger commands Nominal trigger commands

Figure 7.2: Illustration of data flow for two out of 150 APAs in the Single-Phase module. It shows the Cold Electronics WIB-RCE connections which send one half of one APA face to each RCE. The data and L0 trigger primitives the RCEs are received by a single FELIX host. The data is buffered into RAM and the trigger primitives are sent to the Module Trigger Logic unit (MTL) and sent to the Global Trigger Logic unit (not shown). Nominal (non-dump) trigger commands are delivered to the Event Builder which polls the selector on the appropriate FELIX host for the requested data. The MTL sends special SNB-dump trigger commands directly to the Front-End Readout hardware so that it may initiate a full-stream dump to local storage. This dump is then sent out over Ethernet to a special SNB Event builder. Both types of event builders finally save triggered data to file on the offline buffer disk.

fig:daq-readout-buffering-baseline

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Chapter 7: Data Acquisition System 7–70

7.2.3 Local Trigger Primitive Generation (Josh Klein & J.J. Russel & Brett

1

Viren & DP Expert?)

2

sec:fdsp-daq-ltr

Below are from slides bv may show at the Jan WS. Content copied here and now as a starting point.

3

The TPC data is used to generate trigger primitive messages (TPM) local to each APA and

4

which summarize the activity recently sensed by their connected conductors. These TPMs are

5

emited from each APA DAQ Front End and become fodder for later determining trigger command

6

messages (TCM) as described in Section

sec:fdsp-daq-sel

7.2.5.

7

Only the 480 collection channels associated with each APA face are used for forming TCMs.

8

Reasons for this reduction include the fact that collection channels:

9

have higher signal to noise ratio compared to induction channels.

10

fully and independently are sensitive to each APA face.

11

have unipolar signals that directly give an approximate measure of ionization charge without

12

costly field response deconvolution computation.

13

can be divided into smaller groups defined by natural hardware boundaries for parallel pro-

14

cessing.

15

Figure

fig:daq-overview

7.1 illustrates the connectivity between the four connectors on each of the five WIBs and

16

the DAQ APA Front End. The data is received from 80 1 Gbps fiber optical links by four Recon-

17

figurable Computing Elements (RCE) in the ACTA Cluster On Board (COB) system.

18

Matt: help! Each RCE consists of a ....

19

The pattern of connectivity between WIBs and RCEs results in the data from the collection

20

channels covering one half of one APA face being received by each RCE. Each RCE has two

21

primary functions. The first is transmission of all data as described in Section

sec:fdsp-daq-hlt

7.2.4. The second

22

is to produce TPMs from its portion of the collection channel data.

23

The TPMs are produced from a trigger primitive production pipeline of algorithms. These algo-

24

rithms still require development but can be broadly described.

25

1. On a per channel basis calculate a rolling baseline and RMS that characterizes recent samples

26

minimal influence from ionization signal.

27

2. Locate contiguous ADC samples that go above a threshold which is defined in terms of the

28

baseline and RMS.

29

3. Emit their time bounds and total charge as a ROIch TPM.

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Chapter 7: Data Acquisition System 7–71

These ROIch TPM represent some possible activity occurring somewhere in the LAr within a

1

±2.5 mm strip that extends in time by the ROI time bounds. Depending on the threshold set,

2

these TPMs may be numerous due to 39Ar decays and noise fluctuations. Further processing must

3

be done with more global information. This may be done as part of the Module Trigger Logic

4

(MTL) as described in Section

sec:fdsp-daq-sel

7.2.5 or it may be done immediately in the RCE pipeline. Strategies

5

to summarize these detailed TPM into fewer TPMs include:

6

1. Pad each ROIch in a channel by a fixed amount in order to anticipate their use later as defining

7

readout (eg, long enough to account for inter-plane drift times (6.25 µs) and induction signal

8

extents (∼100 µs).

9

2. Form the union of ROI across all channels observed by a given RCE.

10

3. Merge subsequent ROI which are separated by some small time interval.

11

If the Single-Phase detector module generates excess noise, such as that from RF emission picked

12

up coherently across some group of channel, it must be mitigated at the start of the pipeline

13

and will likely require additional computational resources. Some ideas to respond to this scenario

14

include....

15

Ideas?

16

.

17

7.2.4 Dataflow, Trigger and Event Builder (Giles Barr & Josh Klein & Gio-

18

vanna Miotto & Kurt Biery & Brett Viren)

19

sec:fdsp-daq-hlt

Describe the dataflow infrastructure. This should cover transport of data and trigger information, infrastructure for generating local and global trigger commands (but not their algorithms, that’s next), as well as what happens to the data once a trigger is generated (ie. event building). Figure

fig:daq-readout-buffering-baseline

7.2 may be referenced

20

The data volume that is flowing around the DUNE DAQ is considerable, over 10TB/s conntin-

21

uoiusly. However, the control of it is simplified by making the modularity of the primary buffer at

22

the APA level. The majority of the data corresponds to the untriggered parts and never leaves the

23

nodes that house the primary buffers. The parts that do exit in one of three circumstances, (a)

24

as selectd event data (b) as trigger primitives, to be considered on the cavern-wide decision step

25

r (c) as previously triggered supernova burst data being ’trickled out’ from the SSD storage. All

26

thee of these transfers lives entirely in the software domain of a commodity computer farm and so

27

a variety of techniques can be considered for each; in this description, we consider each of them as

28

a data-pull protocol, similar to that in use at ProtoDUNE.

29

artDAQ is a modern, general-purpose framework, that has been used in DUNE prototype tests

30

and elsewhere [refs]. It is optimised further than other frameworks to expliot the paralelism that

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Chapter 7: Data Acquisition System 7–72

is possible with modern multi-core machines. It is the principle architecture that will be used

1

in DUNE. The authors of artDAQ have accomodated DUNE-specific feature-addition requests,

2

an a number of libraries have been used by linking into the ’boardreader’ parts of artDAQ (the

3

parts that handle the incloming data from the data sources), and it is likely that future DUNE

4

extensions will be by one of these two routes.

5

(Section on FELIX data ingress, error handling, synchronisation, ring-buffer expiry). As noted

6

above, one of the complex data flow control tasks is managing the data asit enters the primary

7

buffers on the per-APA nodes. Data throughput on these nodes is governed by the use of the

8

PCIe and memory busses, and so the softwre will be written to mimumize data-copies on the input

9

side of the primary buffer. During normal operation, there must be sufficient ’headroom’ to allow

10

an additional write of data to SSDs during the supernova burst. The current model for dataflow

11

control is tht each APA will operate autonomously, data being written directly from hardware into

12

physical memory and not moved. The softare will keep track of the free and in-use memory (one

13

way is with a ring for each data source) and will maintain an index of the data. One strategy that

14

decentralises the error handling is for the writing to the primary buffer to not cause error handling

15

events, but for it to flag areas of the data for which problems exist only if/when it is to be read

16

again. Similarly to avoid memory alloction error handling, the incoming data can overwrite the

17

lder data and read requests for data that has been overwritten will report the error. It is planned

18

to prototype the data transfers for the TDR.

19

(Section on (a) event building) Requsts for event building (i.e. reading data for succesful triggers

20

from the primary buffers will be donw using mostly standard features that are now in artDAQ. An

21

event-builder node is allocated for each trigger to be read. This event builder then requests portions

22

f data from the primary buffers for the data from that event (this read must be initiated by the

23

request, a difference with the current ProtoDUNE). If the data is missing (either due to errors

24

when it was first received, or because the request arrived so late, that the data were overwritten),

25

the request proceeds, but with flags set in the event header which are displayed on the operators

26

console.

27

(Section on (b) trigger farming) The per-APA-node will receive, or generate the trigger primitives

28

that summarise the hits from each APA, organised in blocks of time. In some circumstances, this

29

is sufficient to declare a trigger, in others, the hit pattern must be combined between APAs to

30

make the trigger decision. The list of APA-level decisions and the trigger primitives are assembled

31

into a block for each time block. Our default scheme for the dataflow is to use a similar method to

32

PotoDUNE, however several others are under study. In the ProtoDUNE method, a trigger farm

33

node is assigned to each time block and requests the trigger data block for it. When it receives

34

the data from all the APAs, it builds an event (using artDAQ funcions), and then processes it, to

35

assign the trigger decisions. One alternative (to avoid the possibility that too many small blocks of

36

data must arrive in one place at a time) is to split the cavern into regions, and have an intermediate

37

layer of data collecton. Another solution is to use data-push, since, it is likely that a single node

38

with a lot of cores can deal with all the trigger processing.

39

(Section on (c) SNB trickling) Because of the ling-term storage capabilities of the SSD drives,

40

there is no hurry to colect the data from them for a supernova. This task can therefore be done in

41

the background (indeed, it should be halted during a subsequent SNB trigger, to avoid increasing

42

the data transfers in the per-APA node). It is anticipated that a spernova collecor node will use

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Chapter 7: Data Acquisition System 7–73

data-pull requests to slowly collect the data from each node and merge it in some way for offline

1

analysis. Probably there will be one data file per APA node which will be collected together in a

2

directory; presumably the offline will not want a single 10TB long file.

3

7.2.5 Data Selection Algorithms (Josh Klein & Brett Viren)

4

sec:fdsp-daq-sel

Data Selection will follow a hierarchical design, beginning with local, APA Level trigger candidates,

5

Module (10 ktonne) Level triggers, and Global (Detector-wide) triggers. A high-level trigger (HLT)

6

may also be active within the Module Level trigger. The hierarchical approach is both natural

7

from a design standpoint, as well as allowing for vertical slice testing and partitioning during

8

commissioning of the system.

9

As discussed above, trigger primitives will be generated in the RCEs from the data stream for

10

each collection wires. The trigger primitives will be summary information for each collection wire,

11

such as the time of any threshold-crossing pulse, its integral charge, and time over threshold. A

12

collection wire with a non-null trigger primitive is said to be “hit.” These trigger primitives are then

13

passed, along with the full data stream, to the FELIX boards and their hosts, each of which handles

14

channels from a small number of APAs (likely two). An APA Level trigger candidate is passed

15

upward to a Module Level trigger, which arbirtrates between various trigger types, determining

16

whether a given APA Level trigger candidate is a valid Module Trigger and whether there are other

17

triggers that have a higher priority in any given slice of time. At this level, a more sophisticated

18

high-level trigger (HLT) may also be employed, which will allow a reduction in trigger rate from

19

various backrounds, including instrumental backgrounds, if needed.

20

A valid Module Level single-interaction trigger sends trigger commands back to the FELIX hosts

21

telling them which slice of time should be saved under the particular trigger header. At the start

22

f DUNE data taking, it is anticipated that for any given single-interaction trigger (a cosmic ray

23

track, for example) waveforms for all wires will be recorded for a full 5.4 ms “readout window.”

24

Such an approach is clearly very conservative, but it ensures that associated low-energy physics

25

(such as neutron captures from neutrons produced by neutrino interactions or cosmic rays) will

26

be recorded without any need to fine-tune APA-level triggering, and will not depend on the noise

27

environment across the APAs. In addition, the 5.4 ms readout window ensures that regardless of

28

when a given even causes a trigger, the entire track is recorded. We anticipate, however, that as

29

we gain experience running DUNE the overall data volume will reduced by writing out data from

30

nly a subset of APAs for any given track, and possibly reducing the size of the readout window.

31

Other trigger streams—calibrations, random triggers, and prescales of various trigger thresholds,

32

will also be generated at the Module Level, and filtering and compression can be applied based upon

33

the trigger stream. For example, a large fraction of random triggers may have their waveforms

34

zero-suppressed, reducing the data volume substantially, as the dominant data source for these

35

will be 39Ar events. Additional signal-processing can also be done on particular trigger streams if

36

needed and if the processing is available, such as fast analyses of calibration data.

37

At the Module Level, a decision can also be made on whether a series of interactions are consistent

38

with a supernova burst. If the number of APA Level low-energy trigger candidates exceeds a

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Chapter 7: Data Acquisition System 7–74

threshold for the number of such events in a given time, a trigger command is sent from the

1

Module Level back to the RCEs, which store up to 10 seconds of unsuppressed, full waveform

2

data. That full waveform is then written out as a separate trigger stream for fast analysis by the

3

supernova working group, perhaps as an automated process. In addition, the Module Level passes

4

information about APA Level trigger candidates up to a detector-wide Global Trigger, which can

5

decide whether, integrated across all modules, enough APAs have detected interactions to qualify

6

for a supernova burst even if within a particular module the threshold is not exceeded. Trigger

7

commands from the Global Trigger Level are passed downward to RCEs in the same way as any

8

Module Level supernova burst trigger would be; at the Module Level, a Global Trigger looks like

9

just one more “external” trigger input.

10

APA Level trigger candidates will be generated within each FELIX host. The trigger decision will

11

be based on the number of adjacent wires hit in a given APA within a narrow time window (roughly

12

100µs), the total charge on these adjacent wires (or any wire with a non-null trigger primitive),

13

and possibly the time-over-threshold for collection wires with hits. Our studies show that even

14

for low-energy events (roughly 10-20 MeV) the reduction in radiological backgrounds is extremely

15

high with such criteria. The highest-rate background, 39Ar, which has a decay rate of 10 MBq

16

within a 10 ktonne volume of argon, has an endpoint of 500 keV and requires significant pileup

17

in both space and time to get near a 10 MeV threshold. Other important background sources are

18

42Ar, which has a 3.5 MeV endpoint and a decay rate of 1 kBq, and 222Rn which has a decay rate

19

f XXXX and decays via a highly-quenched α of 5.5 MeV. The radon decays to 218Po which a few

20

minutes later leads to a quenched α of 6 MeV, and ultimately a 214Bi daughter (many minutes

21

later) which has a β decay with endpoint near 3.5 MeV. The α ranges are short and will hit at

22

most a few collection wires, but the charge deposit can be large, and therefore the charge threshold

23

will have to be well above the α deposits plus any pileup from 39Ar and noise.

24

At the APA Level, two kinds of local trigger candidates can be generated. One is a “high-energy”

25

trigger, that indicates that within a given APA a candidate event with energy more than 10

26

MeV has been found. The thresholds in hit wires, total charge, and time-over-threshold, will be

27

ptimized for at least 50% efficiency at this threshold, with efficiency increasing to 100% via a

28

turn-on curve that ensures at least 90% efficiency at 20 MeV. A second APA Level trigger candiate

29

will be generated for low-energy events, between 5 MeV and 10 MeV. These low-energy APA

30

trigger candidates will not by themselves generate valid Module Level triggers, but rather be used

31

at the Module Level to determine whether a burst of events across many APAs is consistent with

32

a supernova.

33

The Module Level takes as input both APA Level trigger candidates (both low-energy and high-

34

energy), as well as external trigger candidate sources, such as the Global (detector-wide) trigger,

35

external triggers such as SNEWS, and information about the time of a Fermilab Beam spill. The

36

Module Level will also generate internal triggers, such as random triggers and calibration triggers

37

(for example, telling a laser system to fire at a prescribed time). In addition, at the Module Level

38

prescales of all trigger types that normally would not generate a Module Level will be made. For

39

example, a single low-energy trigger does not cause a Module Level trigger on its own, but at some

40

large prescale fraction it could be accepted.

41

The Module Level is responsible also for checking candidate triggers against the current Run

42

Control trigger mask: in some runs, for example, we may decide that only random triggers are

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Chapter 7: Data Acquisition System 7–75

accepted, or that certain APA trigger candidates should not be accepted because those APAs are

1

noisy or misbehaving in some way. In addition, the Module Level will count low-energy trigger

2

candidates from the APAs and, based upon the number and distribution of those triggers in a long

3

time interval (e.g., 10 seconds), decide to generate a supernova burst trigger command. The trigger

4

logic for a supernova burst will be optimized to accept at least 90% of all Milky Way supernovae,

5

and our studies of simple low-energy trigger criteria show that we can likely do much better than

6

that.

7

The HLT can also be applied at this level, particularly if there are unexpectedly higher rates

8

from instrumental or low-energy backgrounds, that require some level of reconstruction or pattern

9

recognition. An HLT might also allow for efficency triggering on lower-energy single interactions,

10

r allow for better sensitivity for supernovae beyond the Milky Way, by employing a weighting

11

scheme to individual APA Level trigger candidates—higher-energy trigger candidates receiving

12

higher weights. Thus, for example, two APA Level trigger candidates consistent with 10 MeV

13

interactions in 10 seconds might be enough to create a supernova burst candidate trigger, while

14

100 5 MeV APA Level trigger candiates in 10 seconds might not. Lastly, the HLT can allow for

15

dynamic thresholding; for example, if a trigger appears to be a cosmic-ray muon, the threshold for

16

single interactions can be lowered (and possibly prescaled) for a short time after that to identify

17

spallation products. In addition, the HLT could allow for a dynamic threshold after a supernova

18

burst, to extend sensitivity beyond the 10 s readout buffer, while not increasing the data volume

19

associated with supernova burst candidates linearly.

20

All low-energy trigger candidates are also passed upwards to the Global trigger level, which can

21

integrate the APA level trigger across all 10 ktonne modules and determine if enough APAs have

22

trigger candidates that a supernova burst may be occuring. This approach increases the sensitivity

23

to trigger bursts by a factor of four (for 40 ktonnes), thus extending the burst sensitivity to a

24

distance twice as far as for a single 10 ktonne module.

25

The Module Level is also responsible for creating a trigger header that includes a global timestamp

26

for the trigger, and information on what type of trigger was created. A log of all APA Level trigger

27

candidates will also be kept, whether or not they are part of a Module Trigger. A

28

s described above, for any high-energy APA Level trigger candidate, a Module Level trigger com-

29

mand is sent to all FELIX hosts instructing them to save a 5.4 ms readout window will written for

30

all wires across all APAs (providing the start and end times to the FELIX hosts). Thus, a DUNE

31

“event” is 5.4 ms of data from all wires in response to a Module Level trigger. The Module Level

32

trigger is also responsible for sending the trigger commands that tell the RCEs to dump their 10

33

s unsuppressed “supernova” buffer. If a supernova burst trigger is created at the Global trigger

34

level, a trigger command is passed back down to the Module Level, which then passes that on to

35

the RCEs for readout of the long (10 s) unsuppressed buffer, the same way it would if a supernova

36

burst is detected at the Module Level.

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Chapter 7: Data Acquisition System 7–76

7.2.6 Timing & Synchronization (David Cussans & Kostas Manolopoulos)

1

sec:fdsp-daq-timing

All components of the DUNE Single Phase detectors are synchronized to a common clock. In

2

rder make full use of the information from the photon detection system the common clock must

3

be aligned within a single detector with an accuracy of O(1ns). In order to form a common trigger

4

for super novae between detector modules the timing between detectors must be aligned with an

5

accuracy of O(1ms). However, a tighter constraint is the need to calibrate the common clock

6

to universal time (derived from GPS) in order to adjust the data selection algorithm inside an

7

accelerator spill, which requires an absolute accuracy of O(1us).

8

Single and Dual phase detector modules use a different timing system, driven by the different

9

technical requirements and development history of the two systems. A single phase detector

10

module has many more timing end-points than a dual phase module and many of the end-points

11

are simpler than the end-points in the dual phase, for example a WIB vs. uTCA crate. Both

12

systems have been sucessfully prototyped.

13

The DUNE Single Phase detectors use a development of the protoDUNE timing system. Syn-

14

chronization messages are transmitted over a serial data stream with the clock embedded in the

15

data. The format is described in DUNE DocDB-1651. Figure

fig:daq-readout-timing

7.3 shows the overall arrangement

16

f components within the Single Phase Timing System(SPTS). A stable master clock, disciplined

17

with a 10MHz reference is used in the SPTS. A one-pulse-per-second (1PPS) signal is also received

18

by the system and is time-stamped onto a counter clocked by the SPTS master clock, however the

19

periodic synchronization messages distributed to the Single Phase detectors are an exact number

20

f clock cycles apart even if there is jitter in the 1PPS signal.

21

The GPS signal is encoded onto optical fibre and transmitted to the CUC, where it is converted

22

back to an RF signal on coaxial cable and used as the input to a GPS displined oscillator. The

23

scillator module also houses a IEEE 1588 (PTP) Grand Master and an NTP server. The PTP

24

Grand Master provides a timing signal for the Dual Phase White Rabbit timing network. The

25

NTP server provides an absolute time for the 1PPS signal. The SPTS relates its time counter onto

26

GPS time by timestamping the 1PPS signal onto the SPTS time counter and reading the time in

27

software from the NTP server.

28

The latency from the GPS antenna on the surface to the GPS receiver in the CUC will be measured

29

by optical time domain reflectometry at installation. Given the modest absolute time accuracy

30

required (sufficient to select data within an accelerator spill) dynamic monitoring of this delay is

31

not required.

32

The White Rabbit synchronization signals from the Dual Phase are time-stamped onto the SPTS

33

clock domain and the SPTS synchronization signals are time stamped onto the Dual Phase clock

34

domain. This allows the timing in the Single Phase and Dual Phase detectors to be aligned. A

35

similar scheme is used to relate the Single Phase protoDUNE Single Phase timing domain to be

36

related to the beam instrumentation White Rabbit time domain.

37

In order to provide redundancy, and also the ability to easily detect issues with the timing path,

38

two independent GPS systems are used. One with an antenna at the head of the Yates shaft,

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Chapter 7: Data Acquisition System 7–77

the other with an antenna at the head of the Ross shaft. The two independent timing paths are

1

brought together in the same rack in the CUC. Using 1:2 fibre splitters one SPTS unit can be

2

left as a hot-spare while the other is active. This also allows testing of new firmware and software

3

during comissioning without the risk of loosing the SPTS if a bug is introduced.

4

Figure 7.3: Illustration of the components in the DUNE Timing System.

fig:daq-readout-timing

All the custom electronic components for the SPTS are contained in two Micro-TCA shelves. At

5

any one time one is active and the other is a hot-spare. The 10MHz reference clock and the 1PPS

6

signal are received by a single width AMC at the centre of the Micro-TCA shelf. This master

7

timing AMC produces the SPTS signals and encodes them onto a serial data stream. This serial

8

datastream is distributed over a standard star-point backplane to the fanout AMCs which each

9

drive the signal onto up to 13 SFP cages. The SFP cages are either occupied by 1000Base-BX

10

SFPs, each of which connects to a fibre running to an APA, or to a Direct Attach cable which

11

connects to systems elsewhere in the CUC, i.e. the RCE crates and the data selection system.

12

This arrangement is shown in figure

fig:daq-readout-sp-timing

7.4

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Chapter 7: Data Acquisition System 7–78

Figure 7.4: Illustration of the components in the Single Phase Timing System.

fig:daq-readout-sp-timing

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SLIDE 96

Chapter 7: Data Acquisition System 7–79

Beam timing

1

The neutrino beam is produced at the Fermilab accelerator complex in spills of 10µs duration. A

2

spill location system (SLS) at the far detector site will locate the time periods in the data when

3

beam could be present, based on network packets received from Fermilab containing preductions

4

f the GPS-time of the spills. data, as it traverses the DAQ system, where beam intractions may

5

be present. Experience from MINOS and NOvA shows that this can provide beam triggering

6

with high reliability, although the system outlined here contains an extra layer of reduncancy in

7

this process. Several stages of narrowing down the window in which the beam arrives will be

8

done, aiming for an accuracy of better than 10% of a drift time, or 0.5ms at the time the data

9

are selected from the DAQ buffers. Ultimately, an offline database will match the actual time of

10

the spill with the data, thus removing any reliance on real-time network transfer for this crucial

11

stage of the oscillation measurements, the network transfer of spill-timing information is simply to

12

ensure a correctly located and sufficiently wide window of data is considered as beam data. This

13

system is not required, and is not designed to provide signals accurate enough to measure neutrino

14

time-of-flight.

15

The precision to which the spill time can be predicted at Fermilab improves as the acceleration

16

process of the protons producing the spill in question advances. The spills currently occur at

17

intervals of 1.3s; the system will be designed to work with any interval, and to be adaptable in

18

case the sequence described here changes. For redundancy, three packets will be sent to the far

19

detector for each spill. The first is approximately 1.6s before the spill-time, which is at the point

20

where a 15Hz booster cycle is selected; from this point on, there will be a fixed number of booster

21

cycles until the neutrinos and the time is subject to a few ms of jitter. The second is about 0.7s

22

before the spill, at the point where the main injector acceleration is no longer coupled to the

23

booster timing; this is governed by a crystal oscillator and so has a few µs of jitter. The third

24

will be at the ‘$74’ which is just before the kicker fires to direct the protons at the LBNF target;

25

this doesn’t improve the timing at the far detector much, but serves as a cross check for missing

26

packets. This system is enhanced compared to that of MINOS/NOvA, which only use the third

27

f the above timing signals. The reason for the larger uncertainty in the time interval from 1.6s to

28

0.7s is that the booster cycle time is synchronised to the electricity supply company’s 60Hz which

29

has a variation of about 1%.

30

Arrival-time monitoring information from a year of MINOS data-taking was analysed, and it was

31

found that 97% of packets arrived within 100ms of being sent and 99.88% within 300ms.

32

The spill location system will therefore have estimators of the GPS-times of future spills, and

33

recent spills contained in the ring buffers. These estimators will improve in precision as more

34

packets arrive. The DAQ will use data in a wider window than usual, if, at the time the trigger

35

decision has to be made, the precision is less accurate due to missing or late packets. From the

36

MINOS monitoting analysis, this will be very rare.

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Chapter 7: Data Acquisition System 7–80

7.2.7 Computing & Network Infrastructure (Kurt Biery & Babak Abi)

1

sec:fdsp-daq-infra

Describes the infrastructure that will support the software components described above.

2

7.2.8 Run Control & Monitoring (Giovanna Miotto & Jingbo Wang

3

sec:fdsp-daq-tcm

Describe how the system is controlled and monitored.

4

7.3 Interfaces (David Cussans & Matt Graham)

5

sec:fdsp-daq-intfc

5 Pages

6

Include an image of each interface in appropriate section. Can maybe refer to Fig.

fig:daq-overview

7.1 but it currently lacks some of the interfaces.

7

7.3.1 TPC Electronics

8

sec:fdsp-daq-intfc-elec

Summarise TPC/DAQ interface

9

7.3.2 PD Electronics

10

sec:fdsp-daq-intfc-photon

Summarise photon system/DAQ interface.

11

7.3.3 Offline Computing (Kurt Biery)

12

sec:fdsp-daq-intfc-fnal-cmptg

Where the data goes after it leaves DAQ.

13

7.3.4 Slow Control

14

sec:fdsp-daq-intfc-ext

Summarise the interface with slow control.

15

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SLIDE 98

Chapter 7: Data Acquisition System 7–81

7.3.5 External Systems (Giles & Alec)

1

sec:fdsp-daq-intfc-ext

Need to receive information on beam spills (Giles) , SNEWS (Alec).

2

The DAQ will need to save data based on external triggers, for example: for times around when the

3

pulse of neutrinos from LBNF arrives at the Far Detector; or if notice of an interesting astrophysical

4

event is given by SNEWS

snews

[?] or LIGO. This could involve going back in time to save data that has

5

already been buffered (see Sec.

sec:fdsp-daq-ltr

7.2.3), or changing the trigger or zero suppression criteria for data

6

in the interesting time period.

7

Beam Trigger: Giles’ stuff including the new ways to generate a predictive trigger?

8

Astrophysical Triggers: The Supernova Early Warning System (SNEWS) is a coincidence net-

9

work of neutrino experiments which are individually sensitive to the burst of neutrinos which

10

would be observed from a core-collapse supernova somewhere in our galaxy. While DUNE should

11

be sensitive to such a burst on its own able to contribute to the coincidence network (Sec.

sec:fdsp-daq-sel

7.2.5)

12

via a tcp socket, being able to save data based on other observations adds an additional chance to

13

not miss saving this rare and valuable data. A SNEWS alert is formed when two or more neutrino

14

experiments report a potential supernova signal within 10 s. The earliest time in the coincidence is

15

then sent via running a script on the SNEWS server at BNL provided by the experiment wishing to

16

receive the alert. The latency from neutrino burst is set by the response time of the second fastest

17

detector to report to SNEWS: this could be as short as seconds, but might be tens of seconds. At

18

latencies larger than 10 s, full data might not be available, but compressed data might writeable.

19

There are other astrophysical triggers available for occurrences which DUNE might not sensitive

20

to individually, but could be either rarely or if taken as an ensemble. Gravitational wave triggers

21

will be available (details being worked out during the current LIGO shutdown), as will high energy

22

photon transients, most notably gamma ray bursts. In fact, cooperation between LIGO/VIRGO,

23

the Gamma Ray Coordinates Network (GCN)1, and a number of automated telescopes via network

24

sockets on the time scale of seconds enabled the discovery that “short/hard” gamma ray bursts

25

are caused by colliding neutron stars

kilonova

[?].

26

7.4 Production and Assembly (David Newbold)

27

sec:fdsp-daq-prod-assy

1 Page

28

1Described in detail at https://gcn.gsfc.nasa.gov/gcn_describe.html

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SLIDE 99

Chapter 7: Data Acquisition System 7–82

7.5 Installation, Integration and Commissioning (David New-

1

bold & Alec Habig)

2

sec:fdsp-daq-install

2 Pages

3

7.5.1 Installation

4

sec:fdsp-daq-install-transport

7.5.2 Integration with TPC/PD Electronics

5

sec:fdsp-daq-install-transport

7.5.3 Commissioning

6

sec:fdsp-daq-commissioning

7.6 Safety (David Newbold & Alec Habig)

7

sec:fdsp-daq-safety

1 Page

8

Two overall safety plans will be followed by the FD-DAQ. Work underground will comply with the

9

safety procedures in place for working in the detector caverns and CUC underground at SURF.

10

In particular, procedures for working with racks full of electronics and/or computers as done at

11

Fermilab will be followed. 2

12

There are not any special safety items for the DAQ system that are not already covered by the

13

more general safety plans referenced above.

14

7.7 Organization and Management (David Newbold & Georgia

15

Karagiorgi)

16

sec:fdsp-daq-org

2 Pages

17

2which we should cite somehow

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SLIDE 100

Chapter 7: Data Acquisition System 7–83

7.7.1 DAQ Consortium Organization

1

sec:fdsp-daq-org-consortium

7.7.2 Planning Assumptions

2

sec:fdsp-daq-org-assmp

7.7.3 WBS and Responsibilities

3

sec:fdsp-daq-org-wbs

7.7.4 High-level Cost and Schedule

4

sec:fdsp-daq-org-cs

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 101

Chapter 8: Slow Controls and Cryogenics Instrumentation 8–84

Chapter 8

1

Slow Controls and Cryogenics

2

Instrumentation

3

ch:fdsp-slow-cryo

8.1 Slow Controls and Cryogenics Instrumentation Overview

4

sec:fdsp-slow-cryo-ov

8.1.1 Introduction

5

sec:fdsp-slow-cryo-intro

The Slow Controls and Cryogenics Instrumentation system provides a comprehensive monitoring

6

and control system for all detector systems and cryogenic instrumentation for the cryostat interior.

7

Write a better description.

8

The system includes (whatever it includes), as shown in Figure....

9

Include an image of the overall system, indicating its parts. Show how the system fits into the

verall detector.

10

The operating principle is illustrated in Figure

fig:sp-cisc-pop

8.1... (add figure)

11

Figure 8.1: required full caption (Credit: xyz)

fig:sp-cisc-pop

8.1.2 Design Considerations

12

sec:fdsp-slow-cryo-des-consid

The Slow Controls and Cryogenics Instrumentation design must enable... ...

13

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SLIDE 102

Chapter 8: Slow Controls and Cryogenics Instrumentation 8–85

Anne suggests: Within this section add ref to requirements document when it’s ready, and maybe list the most important half dozen in a table here). E.g.,

1

Table 8.1: Important requirements on the system design Requirement ...

tab:sp-cisc-requirements

By the end of the volume, for every requirement listed in this section, there should exist an explanation of how it will be satisfied.

2

8.1.3 Scope

3

sec:fdsp-slow-cryo-scope

The scope of the Slow Controls and Cryogenics Instrumentation includes the continued procure-

4

ment of materials for, and the fabrication, testing, delivery and installation of the following systems:

5

Whatever the items are...

6

7
8
9
10

8.2 Cryogenics Instrumentation

11

sec:fdsp-cryo-instr

Include an image of the subsystem, indicating its parts. Show how the system fits into the

verall system).

12

8.2.1 Fluid Dynamics Simulations

13

sec:fdsp-slow-cryo-cfd

provide overview and definition of required CFD, encompassing relevant WBS items for “Sim- ulation studies of fluid dynamics within the cryostat” for the purity monitor system, the temperature measurement system, and the level monitoring...

14

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SLIDE 103

Chapter 8: Slow Controls and Cryogenics Instrumentation 8–86

8.2.2 Purity Monitors

1

sec:fdsp-slow-cryo-purity-mon

A purity monitor (PrM) is a standalone miniature TPC which measures the lifetime of photoelec-

2

trons generated by a UV-illuminated gold photocathode to measure a given substance’s purity. It

3

has high sensitivity to the purity of liquid argon and does not rely on the LArTPC high voltage,

4

electronics, and data acquisition. PrMs are important detectors for guaranteeing successful com-

5

missioning and operation of the LArTPC and meet the requirement to measure position-dependent

6

purity necessary to achieve DUNE’s physics goal. The purity monitors also have the potential to

7

be developed as a calibration tool that provides high precision and real-time electron lifetime

8

measurements for wire-by-wire detector calibration.

9

A purity monitor’s basic design is based on those used by the ICARUS and LAPD experiments

Carugno:1990kd, Adamowski:2014daa

[?, ?]

10

(Figure

fig:prm

??). It is a double-gridded ion chamber immersed in the liquid argon volume. It measures

11

the electron drift lifetime between its anode and cathode. The electrons are generated by the

12

purity monitor’s UV-illuminated gold photocathode. The UV is generated by a xenon flash lamp.

13

The electron lifetime in liquid argon is inversely proportional to the electronegative impurity

14

concentration. The fraction of electrons generated at the cathode that arrive at the anode (QA/QC)

15

after the electron drift time t is a measure of the electron lifetime τ: QA/QC = e−t/τ.

16

8.2.3 Thermometers

17

sec:fdsp-slow-cryo-therm

As mentioned above, a detailed 3D temperature map is important to monitor the correct func-

18

tioning of the cryogenic system and the LAr uniformity. Given the complexity and size of purity

19

monitors, those can only be installed on the cryostat sides to provide a local measurement of the

20

LAr purity. While a direct measurement of the LAr purity across the entire cryostat is not realis-

21

tic, a sufficiently detailed 3D temperature map can be used to predict the LAr purity using CFD

22

simulations. Specially important is the vertical coordinate since this will be closely related to the

23

LAr flow and uniformity.

24

High precision temperature sensors will be distributed near the TPC walls in two ways: i) forming

25

high density (>1 sensor/m) vertical arrays (the so-called T-gradient monitors), and ii) in coarser

26

( 1 sensor/5 m) 2D arrays at the top and bottom of the detector, which are the most delicate

27

regions (the so-called individual sensors).

28

Since temperature variations inside the cryostat are expected to be very small (0.02K), to properly

29

measure the 3D temperature map sensors must be cross-calibrated to better than 0.005K. Most

30

sensors will be calibrated in the laboratory, prior to installation, as described in the next section.

31

This is in fact the only viable method for sensors behind the APAs and top/bottom of the detector

32

since the available space is restricted. Given the precision required and the unknown longevity of

33

the sensors (which could require a new calibration after sometime), and complementary method

34

will be used for T-gradient monitors behind the front end-walls. In those areas there is sufficient

35

space for a movable system, which can be used to cross-calibrate insitu the temperature sensors.

36

This calibration method is described in the section about dynamic T-gradient monitors.

37

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 104

Chapter 8: Slow Controls and Cryogenics Instrumentation 8–87

In the baseline design for all three systems mentioned above three elements are common: the sensor

1

model, the cable model and the readout system. The baseline sensor model is the Lakeshore PT102,

2

which has demonstrated excelent performance in ProtoDUNE-SP. Those sensors have ... For the

3

readout cables a custom cable made by Axon is the baseline. It consists in four teflon-jacketed

4

(extruded PFA) silver platted annealed cupper wires (AWG28), forming two twisted pairs, with

5

an metalic external shield (silver platted annealed cupper) and an outer teflon (extruded PFA)

6

jacket. The cable has a 3.7 mm outer diameter and weights 28 g/m. The redout system will be

7

descrived below in a separate subsection.

8

Static T-Gradient monitors

9

Several vertical arrays of high precision temperature sensors cross-calibrated in the laboratory will

10

be installed behind the APAs. Since the electric potential in this area is zero no electric field

11

shielding is required, simplifying enormously the mechanical design.

12

Sensors are cross-calibrated in the lab using a well controlled environment and a high precission

13

readout system, descrived below in a separate subsection. Four sensors are placed as close as

14

possible in a small cylyndrical aluminum capsule. The capsule is introduced in a polystire box

15

with 15 cm thick walls and a 10x10x15 cm3 empty space. A small quantity of LAr is used to

16

cooldown the capsule to 90K. Then the capsule is covered by LAr such that it penetrates inside

17

fully covering the sensors. Once the temperature stabilizes to the 1 mk level (after 15-30 minutes)

18

measurements are taken.

19

Te baseline design for the mechanics of the system is shown in Fig. ??. It consists in two stailess

20

strings ancored at top and bottom corners of the cryostat using the M10 bolts ... One of the strings

21

is used to route the cables while the other serves as support for temperature sensors.

22

Figure 8.2: Lakeshore PT102 sensor mounted on a PCB with an IDC-4 connector

fig:sensor-support

Dynamic T-Gradient monitors

23

Individual Temperature Sensors

24

T-Gradient monitors will provide a vertical temperature profiling outside the TPCs. Those will

25

be complemented by a coarser 2D array at the top and bottom of the detector. Sensors, cables

26

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SLIDE 105

Chapter 8: Slow Controls and Cryogenics Instrumentation 8–88

and readout will be the same as for the T-gradient monitors.

1

In principle a similar distribution of sensors will be used at TOP and bottom. Following ProtoDUNE-

2

SP design, bottom sensors will use the cryogenic pipes as support structure, while top sensors will

3

be anchored to the ground planes. Teflon (see Fig.

fig:cable-support

8.3) pieces will be used to route cables from

4

the sensors to the DSS/cryogenic ports.

5

Figure 8.3: Left: support for two cables on ground planes. Right: Supports for three cables mounted

n cryogenics pipes using split clamps

fig:cable-support

Readout system for thermometers

6

sec:fdsp-slow-cryo-therm-readout

A high precision and very stable system is required to achieved the design precission of < 5mk.

7

The proposed readout system for the temperature sensors is based on a variant of an existing

8

mass PT100 temperature readout system developed at CERN for one of the LHC experiments.

9

The goal of this system is to improve the precision as a reference system (Lakeshore 218) that

10

the collaboration had evaluated as being appropriate, but with reduced cost and space utilization.

11

The system consists of three parts:

12

An accurate current source for the excitation of the temperature sensors, implemented by a

13

compact electronic circuit using high a precision voltage reference from Texas Instruments.

14

A multiplexing circuit based on an ADG707 Analog Device multiplexer electronic device;

15

A hig resolution and accuracy voltage signal readout module based on National Instruments

16

NI9238, which has 24 bits resolution over 1 Volt range. This module is inserted in a National

17

Instruments Ethernet DAQ backplane, which will distribute the temperature values to the

18

main Slow Control Software through the standard protocol, OPC UA. The Ethernet DAQ

19

will include also the multiplexing logic.

20

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SLIDE 106

Chapter 8: Slow Controls and Cryogenics Instrumentation 8–89

8.2.4 Liquid Level Monitoring

1

sec:fdsp-slow-cryo-liq-lev

8.2.5 Gas Analyzers

2

sec:fdsp-slow-cryo-gas-anlyz

8.2.6 Cameras

3

sec:fdsp-slow-cryo-cameras

Cryogenic Cameras (cold)

4

Inspection Cameras (warm)

5

Light emitting system

6

8.2.7 Cryogenics Test Facility

7

sec:fdsp-slow-cryo-test-facil

8.2.8 Cryogenic Internal Piping

8

sec:fdsp-slow-cryo-int-piping

8.2.9 Local Integration

9

sec:fdsp-slow-cryo-loc-integ

8.2.10 Quality Assurance

10

sec:fdsp-slow-cryo-qa

need this one? left out for now

11

8.3 Slow Controls

12

sec:fdsp-slow-cryo-ctrl

Include an image of the subsystem, indicating its parts. Show how the system fits into the

verall system).

13

8.3.1 Slow Controls Hardware

14

sec:fdsp-slow-cryo-hdwr

Slow Controls Network Hardware

15

sec:fdsp-slow-cryo-slow-network

The Slow Controls data originates from the sensors discussed in Sec.

sec:fdsp-cryo-instr

8.2 and Sec.

sec:fdsp-slow-cryo-slow-dsp

8.3.1, then heads

16

towards the central CISC database housed in the CUC DAQ room (Sec.

sec:fdsp-slow-cryo-slow-compute

8.3.1). It gets there over

17

conventional network hardware from any sensors located in the cryogenic plant. However, the

18

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 107

Chapter 8: Slow Controls and Cryogenics Instrumentation 8–90

readouts which are located in the racks on top the cryostats have to be careful about grounding

1

and noise. Therefore, each rack on the cryostat will have a small network switch which will send

2

any network traffic from that rack to the CUC via a fiber transponder.

3

Network traffic out of SURF to Fermilab will be primarily database calls to that central CISC

4

DB: either from monitoring applications, or from database replication to the offline version of the

5

CISC DB. This traffic is of a low enough bandwidth that the proposed general purpose links both

6

ut of the mine and back to Fermilab can accommodate it.

7

Slow Controls Computing Hardware

8

sec:fdsp-slow-cryo-slow-compute

Up to two racks of space and appropriate power and cooling are available in the CUC’s DAQ

9

server room for CISC usage. Somewhat less space than that is currently envisioned: Two servers

10

(a primary server and a replicated backup) suitable for the needed relational database discussed

11

in Sec.

sec:fdsp-slow-cryo-sw

8.3.3 will be there, with an additional two servers to perform front-end monitoring inter-

12

face services: for example, assembling dynamic CISC monitoring web pages from the adjacent

13

databases. Any special purpose software, such as iFix or EPICS, would also run here: two more

14

servers (for a total of six) will accommodate these programs.

15

I am completely making up how many special purpose iFix machines there should be: need input from the cryo people

16

Replicating this setup on a per-module basis would allow for easier commissioning and independent

17

peration, accommodate different module design (and the resulting differences in database tables),

18

and ensure sufficient capacity. Including fours sets of networking hardware, this would fit tightly

19

into one rack or very comfortably into two.

20

Slow Controls Signal Processing Hardware

21

sec:fdsp-slow-cryo-slow-dsp

Is this the place for the laundry list of Things to Be Monitored? (but which are not cryo related)

22

8.3.2 Slow Controls Infrastructure

23

sec:fdsp-slow-cryo-slow-infra

8.3.3 Slow Controls Software

24

sec:fdsp-slow-cryo-sw

Glenn’s talk from the parallel session @CERN is a great starting point here

25

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 108

Chapter 8: Slow Controls and Cryogenics Instrumentation 8–91

8.3.4 Slow Controls Quantities

1

sec:fdsp-slow-cryo-quant

8.3.5 Local Integration

2

sec:fdsp-slow-cryo-slow-loc-integ

8.3.6 Quality Assurance

3

sec:fdsp-slow-cryo-slow-qa

need this one? not assigned

4

8.4 Production and Assembly

5

sec:fdsp-slow-cryo-prod-assy

This section not needed? Not assigned; may be addressed in earlier sections.

6

8.5 Interfaces

7

sec:fdsp-slow-cryo-intfc

Include an image of each interface in appropriate section.

8

Add in appropriate subsections for the pieces that this interfaces with. These initial ones may not be right, or some interfaces may be missing.

9

The cryogenics instrumentation and slow control systems interface with most other DUNE systems,

10

including LBNF and the cryogenics system. A detailed description of all interfaces is available

11

elsewhere (DUNE-doc-6383-v1). Here a brief summury is given. There are many aspects that are

12

common to mamy systems. Thoise are listed below:

13

Particularely important is the interface with HV system since several aspects related with safety

14

must be taken into account.

15

8.5.1 Interface with External Cryogenics Systems

16

sec:fdsp-slow-cryo-ext-cryo

specify external interface of Cryo Inst. Systems with systems outside the cryostat (with LBNF), detector Interface to LBNF design teams working on the design on cryogenic systems (including cryogenic piping)

17

This includes external cryogenics piping

18

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 109

Chapter 8: Slow Controls and Cryogenics Instrumentation 8–92

The external cryogenics piping is responsability of LNBF while the internal pipes are under CISC.

1

The proper interfaces should be defined.

2

The switchyard for the gas analyzers ...

3

8.5.2 Interface with Environmental and Building Controls

4

sec:fdsp-slow-cryo-slow-enviro

describe interface with LBNF on environmental and building controls

5

Building Temperature, humidity and pressure will be monitored and integrated into the slow

6

controls system.

7

8.5.3 Interface with High Voltage Systems

8

sec:fdsp-slow-cryo-slow-hv

Describe interface with HV systems, including use of cameras for HV monitoring, and also drift HV, current toroid, ground planes, and field cage pickoffs

9

The cryogenics instrumentation and slow control system have multiple interfaces with the HV

10

systems.

11

The hardware interface between CISC and HV has multiple components:

12

Understand the location of cold cameras and lights for inspection of HV related devices, as

13

well as the requirements of cold/warm cameras: resolution, field of view, light sensitivity,

14

low light operation, frames per second, operation in triggered mode?, etc.

15

During the deployment of inspection cameras, avoid generation of bubbles when HV is on as

16

it can lead to discharges.

17

As in ProtoDUNE-SP, ground planes (GP) could be used as support for temperature sensors

18

(RTDs). GP could be also used as support for cold cameras.

19

electrostatic simulations to make sure instrumentation devices in the cryostat have the proper

20

shielding

21

Software: CISC will provide full control and monitoring of the HV PS including alarms, archiving

22

and GUIs for all HV devices, whose definition and implementation must be agreed among the

23

two consortia. Special software may be needed to detect discharges using the camera system,

24

which will be the responsibility of the HV consortium. For all instrumentation devices inside the

25

cryostat, E-field simulations are needed to guaranty proper shielding is in place. Although this is a

26

CISC responsibility, input from HV will be crucial. Finally, CISC should monitor the various HV

27

interlock status bits. For all HV racks, CISC will provide full rack monitoring which will include

28

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 110

Chapter 8: Slow Controls and Cryogenics Instrumentation 8–93

rack protection system, temperatures and fans (if any).

1

Signals: Data from cameras for inspection of HV devices and for detection of discharges may need

2

special treatment.

3

8.5.4 Interface with DAQ/Electronics

4

sec:fdsp-slow-cryo-slow-daq

Describe interface with DAQ system, including Interface with DAQ/Electronics groups for a slow controls test facility at SURF, possibly as part of the DAQ test stand

5

8.5.5 Interface with Other Systems

6

sec:fdsp-slow-cryo-slow-other

There are also inerfaces with the Photon Detection system. Purity Monitors and Light emitting

7

system for Cameras both emit light that might damage PDs. Although this should be understood

8

and quantified, CISC and SP-PD may have to Define the necessary hardware interlocks that avoid

9

turning on any other light source accidentally when PDs are on.

10

8.6 Installation, Integration and Commissioning

11

sec:fdsp-slow-cryo-install

The installation of cryogenics instrumentation devices will be done in several phases:

12

1. Before detector installation: Individual temperature sensors anchored to the cryogenic pipes

13

at the bottom of the cryostat and static T-gradient monitors will be installed right after the

14

installation of the pipes. Additional level meters could be also installed during this phase.

15

2. During detector installation: Temperature sensors anchored to the top ground planes will be

16

installed in several steps

17

3. After detector installation: dynamic T-gradient monitors and purity monitors will be in-

18

stalled once the detector in installed.

19

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 111

Chapter 8: Slow Controls and Cryogenics Instrumentation 8–94

8.6.1 Transport and Handling

1

sec:fdsp-slow-cryo-install-transport

8.6.2 Integration Facility Operations

2

sec:fdsp-slow-cryo-install-facil-ops

8.6.3 Underground Operations

3

sec:fdsp-slow-cryo-install-undergr

8.6.4 Commissioning

4

sec:fdsp-slow-cryo-install-commiss

Some parts of the CISC system will be commissioned prior to HV commissioning, and before cryo-

5

stat filling with LAr. This is the case for RTDs on GPs, cold and inspection cameras and thermal

6

interlocks for PS. Final commissioning of those systems will be done once the cryostat is filled,

7

since operation will be different in the presence of LAr. Commissioning the control/monitoring

8

f HV PS and any related hardware interlocks could probably be done at an early stage as well,

9

provided no real HV is provided to the cathode/field-cages. Final commissioning will be done once

10

HV is switched on. This will also require coordination from other groups such as LBNF, DAQ,

11

APA etc. The commissioning of the interfacing elements should follow naturally after (successful)

12

integration testing.

13

8.7 Quality Control

14

sec:fdsp-slow-cryo-qc

8.8 Safety

15

sec:fdsp-slow-cryo-safety

8.9 Organization and Management

16

sec:fdsp-slow-cryo-org

structure under here is recommended

17

8.9.1 Slow Controls and Cryogenics Instrumentation Consortium Organiza-

18

tion

19

sec:fdsp-slow-cryo-org-consortium

8.9.2 Planning Assumptions

20

sec:fdsp-slow-cryo-org-assmp

8.9.3 WBS and Responsibilities

21

sec:fdsp-slow-cryo-org-wbs

8.9.4 High-level Cost and Schedule

22

sec:fdsp-slow-cryo-org-cs

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 112

Chapter 9: Technical Coordination 9–95

Chapter 9

1

Technical Coordination

2

ch:fdsp-coord

9.1 Project Support

3

sec:fdsp-coord-supp

9.1.1 Project Controls

4

sec:fdsp-coord-controls

9.1.2 Reviews

5

sec:fdsp-coord-reviews

9.1.3 Quality Assurance

6

sec:fdsp-coord-qa

9.1.4 ES&H

7

sec:fdsp-coord-esh

9.1.5 Integration and Systems Engineering

8

sec:fdsp-coord-integ-sysengr

Configuration Management

9

sec:fdsp-coord-integ-config

The DUNE Technical Coordination project engineering team will maintain full 3-D CAD models

10

f the detectors, and the consortia will be responsible for providing the team with CAD models

11

f their detector components for integration into the overall models.

The project engineering

12

team will work with the LBNF project team to integrate the full detector models into a global

13

LBNF CAD model that includes cryostats, cryogenic systems, and the conventional facilities. The

14

DUNE project engineering team will work directly with the Consortia Technical Leads and their

15

supporting engineering teams to resolve any detector component interference and/or connection

16

issues with other detector systems, detector infrastructure, and facility infrastructure.

17

At the time of the release of the Technical Design Reports, the project engineering team will

18

work with the consortia to produce formal engineering drawings for all detector components.

19

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 113

Chapter 9: Technical Coordination 9–96

These drawings are expected to be signed by the consortia Technical Leads, project engineers,

1

and Technical Coordinator. Starting from that point, the detector models and drawings will sit

2

under formal change control. It is anticipated that designs will undergo further revisions prior to

3

the start of detector construction, but any changes made after the release of the Technical Design

4

Reports will need to be agreed to by all of the drawing signees and an updated, signed drawing

5

produced.

6

(1) 3-D Model (2) Interface Definitions (3) Envelope Drawings for installation (4) Drawing man-

7

agement

8

Engineering process and support

9

sec:fdsp-coord-integ-engr-proc

The DUNE Technical Coordination organization will work with the consortia through its project

10

engineering team to ensure the proper integration of all detector components. The project engi-

11

neering team will document requirements on engineering standards and documentation that the

12

consortia will need to adhere to in the design process for the detector components under their

13

responsibility. Similarly, the project QA and ES&H managers will document quality control and

14

safety criteria that the consortia will be required to follow during the construction, installation,

15

and commissioning of their detector components.

16

Consortia interfaces with the conventional facilities, cryostats, and cryogenics are managed through

17

the DUNE Technical Coordination organization. The project engineering team will work with the

18

consortia to understand their interfaces to the facilities and then communicate these globally to

19

the LBNF project team. For conventional facilities the types of interfaces to be considered are re-

20

quirements for bringing needed detector components down the shaft and through the underground

21

tunnels to the detector cavern, overall requirements for power and cooling in the detector caverns,

22

and the requirements on cable connections from the underground area to the surface. Interfaces

23

to the cryostat include the number and sizes of the penetrations on top of the cryostat, required

24

mechanical structures attaching to the cryostat walls for supporting cables and instrumentation,

25

and requirements on the global positioning of the detector within the cryostat. Cryogenic system

26

interfaces include requirements on the location of inlet/output ports, requirements on the monitor-

27

ing of the liquid argon both inside and outside the cryostat, and grounding/shielding requirements

28

n piping attached to the cryostat.

29

LBNF will be responsible for the design and construction of the cryostats used to house the

30

detectors. The consortia are required to provide input on the location and sizes of the needed pen-

31

etrations at the top of the cryostats. The consortia also need to specify any mechanical structures

32

to be attached to the cryostat walls for supporting cables or instrumentation. The DUNE project

33

engineering team will work with the LBNF cryostat engineering team to understand what attached

34

fixturing is possible and iterate with the consortia as necessary. The consortia will also work with

35

the project engineering team through the development of the 3-D CAD model to understand the

36

verall position of the detector within the cryostat and any issues associated with the resulting

37

locations of their detector components.

38

LBNF will be responsible for the cryogenics systems used to purge, cool, and fill the cryostats. It

39

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 114

Chapter 9: Technical Coordination 9–97

will also be responsible for the system that continually re-circulates liquid argon through filtering

1

systems to remove impurities. Any detector requirements on the flow of liquid within the cryostat

2

should be developed by the consortia and transmitted to LBNF through the project engineering

3

team. Similarly, any requirements on the rate of cool-down or maximum temperature differen-

4

tial across the cryostat during the cool-down process should be specified by the consortia and

5

transmitted to the LBNF team.

6

9.2 Installation

7

sec:fdsp-coord-install

9.2.1 Organization

8

sec:fdsp-coord-org

9.2.2 Integration and Test Facility

9

sec:fdsp-coord-integ-test

Baseline scope

10

sec:fdsp-coord-integ-test-base

Alternatives

11

sec:fdsp-coord-integ-test-alt

9.2.3 Underground Detector Installation

12

sec:fdsp-coord-undergd

Baseline scope

13

sec:fdsp-coord-undergd-base

Alternatives

14

sec:fdsp-coord-undergd-alt

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

SLIDE 115

Chapter 10: Detector Performance 10–98

Chapter 10

1

Detector Performance

2

ch:fdsp-perform

10.1 ??

3

sec:fdsp-perform-??

23 Feb 2018: First draft of the TP volumes due DUNE Technical Proposal

Deep Underground Neutrino Experiment (DUNE)

Technical Proposal

23 Feb 2018: First draft of the TP volumes due

Volume 2: The Single-Phase Far Detector

Contents

List of Figures

List of Tables

Todo list

Chapter 1

Design Motivation

1.1 Introduction to Single-Phase Far Detector in DUNE/LBNF

1.2 DUNE Physics

1.2.1 Goals (Oscillation Physics, Supernova Neutrinos, Proton Decay)

1.2.2 Requirements

1.3 Single-Phase LArTPC for DUNE

1.4 Operational Principle

1.5 Implementation of Single-Phase LArTPC Design at DUNE

Chapter 2

Overview of the Single-Phase Detector

Module Design

2.1 Model of the TPC, and coordinate definitions

2.2 Primary Detector Systems

2.2.1 APAs

2.2.2 HV

2.2.3 Electronics

2.2.4 Photon Detector

2.2.5 DAQ

2.2.6 Instrumentation: Slow Controls and Cryogenics

Chapter 3

Anode Plane Assemblies

3.1 Anode Plane Assembly (APA) Overview

3.1.1 Introduction

3.1.2 Design Considerations

3.1.3 Scope

3.2 APA Design

3.2.1 Frame and Mesh

3.2.2 Anchoring Elements and Wire Boards

3.2.3 Wires

3.2.4 Quality Assurance

3.3 Production and Assembly

3.3.1 Production Plan

3.3.2 Facility Plans

3.3.3 Wire Winding Machine

3.3.4 Tooling

3.3.5 Assembly Procedures, Travelers, and Documentation

3.4 Interfaces

3.4.1 LBNF Cryostat and Detector Support Structure

3.4.2 Photon Detection System

3.4.3 TPC Electronics

3.5 Installation, Integration and Commissioning

3.5.1 Transport and Handling

3.5.2 Integration with PDS and TPC Electronics

3.5.3 Calibration

3.6 Quality Control

3.6.1 Protection and Assembly (Local)

3.6.2 Post-factory Installation (Remote)

3.7 Safety

3.8 Organization and Management

3.8.1 APA Consortium Organization

3.8.2 Planning Assumptions

3.8.3 WBS and Responsibilities

3.8.4 High-level Cost and Schedule

Chapter 4

High Voltage System

4.1 High Voltage System (HV) Overview

4.1.1 Introduction

4.1.2 Design Considerations

4.1.3 Scope (Rob)

4.2 HV System Design

4.2.1 High Voltage Power Supply and Feedthrough (Sarah)

4.2.2 CPA (Vic, Steve)

4.2.3 Field Cages

4.2.4 Electrical Interconnections (Glenn)

4.2.5 Quality Assurance

4.3 Production and Assembly

4.3.1 Power Supplies and Feedthroughs

4.3.2 CPA

4.3.3 Field Cages

4.3.4 Electrical Interconnections

4.4 Interfaces (Bo)