[PPT] - Design and status of the Mu2e crystal calorimeter Raffaella Donghia PowerPoint Presentation

SLIDE 1

Design and status of the Mu2e crystal calorimeter

Raffaella Donghia

National Laboratory of Frascati of INFN On behalf of the Mu2e calorimeter group June 11, 2019 New Perspectives 2019 Fermi National Accelerator Laboratory

SLIDE 2

CLFV @ Mu2e

25 m

Production Solenoid / Target

Protons hitting target and producing

mostly π Tr Transport Solenoid

Selects and transports low

momentum μ-

PS TS

De Detector Sol

lenoi
id: stopping target & detector
rs
Stops μ- on Al foils
Events reconstructed by detectors optimized

for 105 MeV/c momentum

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 1

DS

CLFV strongly suppressed in SM: Branching Ratio ≤10-54

à Observation would indicate New Physics

CLFV @ Mu2e: μ- e conversion in the field of a nucleus

à discovery sensitivity to many NP models

µ e Al

ECE = mµc2 – Eb – Erecoil= = 104.97 MeV < 8.4 x 10-17

M

r

e i n f

r

m a t i

n

i n Y u j i n g t a l k

SLIDE 3

Calorimeter requirements

σE/E = 𝓟(10%) for CE
σT < 500 ps for CE
σX,Y ≤ 1 cm
Fast signals, τ<40 ns
Operate in 1 T and in vacuum at 10-4 Torr
Re

Redundancy in readou

ut ( 2 se

senso sors+ rs+FEE /c /crystal)

Ra

Radiation

n hardness (safe

fety fa factor

r of
f 3):
100

100 kr krad (4 (45 kr krad) ) dose for crystals (s (sensors)

3x

3x10 1012

12 n1M 1MeV eV/c

/cm2

2 (1

(1.2x1012

12 n1M 1MeV eV/c

/cm2) ) for crystals (s (sensors) )

Low radiation induced readout noise < 0.6 MeV

The electromagnetic calorimeter (EMC) should provide high acceptance for reconstructing energy, time and position of conversion electrons (CE) and provide: 1) 1) PI PID: e/μ se separa rati tion 2) 2) EMC EMC seeded track fi finder 3) 3) Fa Fast and nd track-in independent trig igger

Requirements @ 105 MeV/c

Front Disk Dose – 1 year [krad] June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 2

SLIDE 4

Calorimeter Design

Tw Two annular disks with 674 und undoped ed Cs CsI (3 (34 x x 34 x x 200) ) mm3

3 sq

square cryst stals s each

RIN = 374 mm, ROUT = 660 mm
Depth = 10 X0 (200 mm); Distance = 70 cm
Redundant readout:

2 2 UV-ex extended ended Si SiPMs/c /crystal (Mu2e Si SiPMs) à 50 50 um um pi pixel el, 12x 12x18 18 mm2 ac active ar area

1 FEE / SiPM, digital readout on crates
Lo

Long R&D phase to select final producer

BETTER PICTURE!!

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 3

~ 150 V i1≈ i2 ≈ i3 Ctot ≈ C/3

6x6 mm2 K1 A1

SLIDE 5

t wrapped

Module 0

Large EMC prototype: 51 crystals, 102 SiPMs, 102 FEE boards Mechanics and cooling system similar to the final ones but smaller scale à Main goals:

Integration and assembly procedures
Test beam May 2017, 60-120 MeV e- ( @ 0° and @ 50°)
Work under vacuum, low temperature, irradiation test

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 4

Readout: 1 GHz CAEN digitizers (DRS4 chip), 2 boards x 32 channels

SLIDE 6

Highest Energy Crystal [MeV]

Single particle selection
MIPs Equalization & E-scale
LY/SiPM = 30 pe/MeV
Great Data-MC agreement

Module 0 TB results

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 5

σE E = a √ E ⊕ b E ⊕ c

σE ~ 7.3 % Beam @ 50°

Energy response Time response

TimeHist

/ ndf

2

106.6 / 20 0.0444 0.6526 1.21 17.12 0.7 216.6 N 640.2 8782 t [ns] 200 400 600 800 1000 Amplitude [mV] 50 100 150 200 250 300 350

TimeHist

/ ndf

2

106.6 / 20 0.0444 0.6526 1.21 17.12 0.7 216.6 N 640.2 8782

Χ η σ µ

Δ

Energy [MeV] 10 20 30 40 50 60 70 80 90 100 [ns]

T

σ 0.05 0.1 0.15 0.2 0.25 0.3 0.35

/ ndf

2

χ 1.631 / 5 a 0.2011 ± 6.29 b 0.006919 ± 0.08285 / ndf

2

χ 1.631 / 5 a 0.2011 ± 6.29 b 0.006919 ± 0.08285 / ndf

2

χ 2.776 / 3 a 0.1399 ± 4.85 b 0.004284 ± 0.06402 / ndf

2

χ 2.776 / 3 a 0.1399 ± 4.85 b 0.004284 ± 0.06402

Beam at 0

Cosmic Rays - Hamamatsu

Beam at 50

Cosmic Rays - SensL

σT = a/E + b

Δ

Entries 1531 / ndf 2 19.56 / 15 Constant 7.6 240.9 Mean 0.0049 0.1664 Sigma 0.0035 0.1874

t [ns] 1.5 1 0.5 0.5 1 1.5 Entries / (0.075 ns) 50 100 150 200 250

Entries 1531 / ndf 2 19.56 / 15 Constant 7.6 240.9 Mean 0.0049 0.1664 Sigma 0.0035 0.1874

Central crystal (TSiPM 1 – TSiPM2) Δ

Time response

Log-normal fit on leading edge
Constant Fraction method used à CF = 5%

SLIDE 7

More details on E.Diociaiuti poster

QA of components for production (2018-2019)

Dedicated QA laboratory at SiDet (FNAL) è production started on March 2018 Additional laboratories for crystals and irradiation testing at Caltech and HZDR

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Light Yield

Crystals SiPMs

More than 1000 crystals already tested from SICCAS (rate: 60 crystals/month), SG almost same rate

Optical properties measurements:

LY, LRU, resolution, slow component, RIN About 3200/4000 Mu2e SiPMs already characterized Producer: HAMAMATSU

280 pieces/month
All 6 cells tested, measuring Vbr, Idark, Gain x PDE
Irradiation with ~1x1012 neutrons/cm2 (MTTF) test
n 5 (15) SiPMs/batch

RMS (Vbr) RMS (Idark)

SLIDE 8

FEE & Digital readout

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 7

De Dedica cated FEE board on each ch Si SiPM PM: :

2 amplification stages (x 2, x4)
Linear regulation of bias voltage
Shaping:

à Rise time 50 ns à Full width 200 ns

1 V dynamic range
Monitoring of SiPM currents/temperature
rad-hard up to 100 krad

10 10 crates es per er disk with h 6-8 8 digital boards/crate

20 SiPM+FEE channels per board
Mezzanine (M

(MB): input FEE signals, HV to SiPMs

DI

DIRAC board provides digitization at 200 Msps, 12 bit ADC

DC-DC converter
VTRX optical readout
Final Rad-Hard FPGA PF300TàRad-hard up to 15

15 kr krad

MB DIRAC

SLIDE 9

Final Mechanical design

June 11, 2019 8

Crystals stacked from the bottom to the top inside an external stainless steel cylindrical support

FEA completed: good stability, small stress on support legs
Inner cylinder: composite material
FEE plate: PEEK
CF front face with source tubing integrated
FEE crates mounted on the external cylinder

mockup with fake iron crystals Geant4 simulation NP19 - Mu2e Calorimeter, R.Donghia

2 calibration systems integrated: radioactive source and laser system

SLIDE 10

Additional IN-SITU calibrations

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dE/dX à equalize and calibrate the energy response;
Time of flight à to align the time offsets
Energy scale at O( 1%)
Estimated time 6 hours
Continuous monitor E-T resolution
calibrate T0s @ a level below 30 ps (RMS)

Cosmic Rays DIO electrons

Calibration relative to tracker measurements

High energy tracks from DIO electrons
Absolute calibration at 0.5 T
Calibration extrapolation to 1 T, accuracy ~ 0.2%

SLIDE 11

Calorimeter Assembly room

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 10

Getting ready to start assembly in November 2019!

Assembly Room under construction at FNAL in SiDet
Completion scheduled for March 2019

Stacking procedure

f wrapped crystals OK

New Photo

SLIDE 12

Summary and Conclusions

The Mu2e calorimeter concluded its prototyping phase satisfying the

Mu2e requirements:

Un-doped CsI crystals perform well

§ Excellent LRU and LY > 100 pe/MeV ( PMT+Tyvek wrapping ) § τ of 30 ns, negligible slow component § Radiation hardness OK: 40% LY loss at 100 krad

Mu2e SiPMs quality OK
High gain, high PDE, low Idark, low RMS spread in array
SiPMs performance after irradiation OK à require 0 °C cooling
Calorimeter prototypes tested with e- beam

§ Good time and energy resolution achieved @ 100 MeV

Calorimeter production phase started March 2018
Production will end in October 2019, FEE production on summer 2019
Calorimeter assembly expected by the end of 2019
Calorimeter installation in Mu2e experimental hall planned for 2020

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 11

SLIDE 13

Thanks for listening

Raffaella Donghia

On behalf of the Mu2e calorimeter group June 11, 2019 New Perspectives 2019 Fermi National Accelerator Laboratory

SLIDE 14 Entries 102900 Mean 90.09 Mean y 60.63 RMS 63.51 RMS y 110.6

Time [ns] 50 100 150 200 Amplitude [mV] 100 200 300 400 500

Entries 102900 Mean 90.09 Mean y 60.63 RMS 63.51 RMS y 110.6 Entries 102900 Mean 90.04 Mean y 33.18 RMS 63.51 RMS y 33.26

Time [ns] 50 100 150 200 Amplitude [mV] 20 40 60 80 100 120 140 160

Entries 102900 Mean 90.04 Mean y 33.18 RMS 63.51 RMS y 33.26

/MeV

pe

N 100 110 120 130 140 150 160 170 180 190 200

Entries

2 4 6 8 10

Entries

σ

Entries Entries

LRU (%) 1 2 3 4 5 6 7 8 9 10

Entries

2 4 6 8 10 12 σ

Entries

Intense R&D (2016-2017)

24 crystals from SI

SICCAS, Am Amcrys, Sa Saint nt Go Gobai ain

Optical properties tested with 511

511 ke keV γ’s ’s

150 μm Ty

Tyvek+UV-extended PM PMT readout

Amcrys discarded for RIN properties

Light Yield Longitudinal Resp. Uniformity

RMS/MEAN of Light Output values along axis

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 13 Entries 72

Crystals Mu2e-SiPM Mu2e custom photosensors: 2 2 arrays of 3 3 6x 6x6 6 mm2 UV UV-ex extend ended ed Si SiPM PMs

reduction of the overall capacitance
faster signals

Single cell of 6 x 6 mm2 Series of 3 cells

Prototype TB

h

Entries Mean 0 RMS 0 Energy [GeV] 0.02 0.03 0.04 0.05 0.06 0.07 0.08 0.09 [ns]

t

s 0.05 0.1 0.15 0.2 0.25 0.3

h

Entries Mean 0 RMS 0 / ndf

2

c 38 / 17 a 0.00015 ± 0.0049 b 0.0033 ± 0.087 / ndf

2

c 38 / 17 a 0.00015 ± 0.0049 b 0.0033 ± 0.087

b Å = a/E

t

s

Single crystal @ 0 deg All crystals above 10 MeV @ 0 deg Cosmics Neighboring crystals @ 50 deg Single crystal @ 50 deg Most energetic crystal @ 50 deg All crystals above 10 MeV @ 50 deg

Total energy [GeV] 0.07 0.075 0.08 0.085 0.09 0.095 0.1 0.105 /E [%]

E

s 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 / ndf

2

c 2.866 / 3 a 0.3253 ± 1.38 b 1.092 ± 4.911 / ndf

2

c 2.866 / 3 a 0.3253 ± 1.38 b 1.092 ± 4.911

data Monte Carlo

b Å E [GeV] a = E

E

s

Small prototype 3x3 tested @ BTF (LNF, 2015)

80

80-120 120 MeV eV e-

At 100: σE~7%, σT ~ 110 ps at 100 MeV

~ 150 V

i1≈ i2 ≈ i3 Ctot ≈ C/3 6x6 mm2 K1 A1

JINST 12 (2017) P05007

SLIDE 15

Straw tubes

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SLIDE 16

Straw tube tracker

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SLIDE 17

Background

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SLIDE 18

Time (ns) 200 400 600 800 1000 1200 1400 1600 1800 0.01 0.02 0.03 0.04 0.05 0.06 0.07 0.08

POT pulse 1M ) × arrival/decay time (

π

400 ) × arrival time (

µ

400 ) × decay/capture time (

µ

Beam structure

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 17

SLIDE 19

Simulated performance

ion Simulation includes full background

The overall resolution depends on

properties of the crystals

Several crystals considered

LRU: RMS/MEAN of Light Output values along axis

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 18

LYSO BaF2 CsI Radiation Length X0 [cm] 1.14 2.03 1.86 Light Yield [% NaI(Tl)] 75 4/36 3.6 Decay Time[ns] 40 0.9/650 20 Photosensor APD RMD APD SiPM Wavelength [nm] 402 220/300 310 $

SLIDE 20

Calibration source and laser

Laser system to monitor SiPMs gain and timing performance

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Liquid source FC 770 + DT generator: 6 MeV + 2 escape peaks à E-scale 2k entries/crystal/min

SLIDE 21

Electronics: FEE test up to 120 krad

q all analog parts of Amplifier and HV regulator OK q LT ADC/DAC of digital session suffering from 10-15 krad up q new rad-hard ADC/DAC identified from Texas Instrument q PCB with TI ADC/DAC ready for new irradiation test è 28 January

June 11, 2019 20

0,000 100,000 200,000 300,000 400,000 500,000 600,000 700,000 800,000 900,000

Output pulse amplitude [mV] DOSE [Krad]

Analog output pulse amplitude reading

n a standard preamplifier without DAC

Gamma tests in detail - Analog electronics (1 of 6)

NP19 - Mu2e Calorimeter, R.Donghia

SLIDE 22

Electronics: DIRAC test up to 80 krad

June 11, 2019 21

PolarFire test with evaluation board DC-DC converter test

ADC and jitter cleaner tested up to 40 Krad. OK
Polarfire: routing and logic delays measured. No changes up to 77
Krad. Reprogrammability checked at 53 Krad still ok. Problems > 77

looks due to DC DC converter

DCDC converters: LTM8053 OK up to 50 Krad, LMZ31710 broke at 32

Krad two times. Both still ok for ECAL. Test in B field to be repeated

NP19 - Mu2e Calorimeter, R.Donghia

SLIDE 23

June 11, 2019 22

Summary CsI production

SICCAS

§ 622 crystals received /725 = 86% § Rejection factor 3%

End of SICCAS production: Apr 2019

à StGb getting stabilized

à October 2018: 25 crystals received with high rejection factor: 41% à Dec 18: 63=25+38 crystals received Rejection factor = 10/63 = 16% Þ End of January +48 crystals Þ Very good quality + 30 arrive this week Bi-weekly phone call established End of SgB production è Oct 2019

Siccas St.Gobain Total

Shipped

622/725 242/725 864/1450

Arrived 622 242 864 CMM + inspection 622 242 864 Sent to Caltech 184 16 210 Back to Vendor 13 44+20 73

Irradiation at Caltech 8

8

NP19 - Mu2e Calorimeter, R.Donghia

SLIDE 24

June 11, 2019 23

SiPM production

q All 12 shipments of the standard production (3360) received q Schedule is to complete QA production test for end of March. q Two additional shipments expected with the schedule of

f completing their QA in May 2019 and reach 4000 sensors

Up to yesterday: è Geometry checked: Batch # 12 (3360) è QA station (Idark, I-V and Gain) checked: Batch # 10 (2750) è Irradiation test up to batch #7 (see next page) è MTTF test keep working w.o. deads .. à MTTF > 10 million hours

NP19 - Mu2e Calorimeter, R.Donghia

SLIDE 25

SiPM irradiation with neutron

June 11, 2019 24

0,5 1 1,5 2 2,5 3 3,5

6,0
5,0
4,0
3,0
2,0
1,0

0,0

Batch 1-2; Comparison @ -10C

0,5 1 1,5 2 2,5 3 3,5 4 4,5

6,0
5,0
4,0
3,0
2,0
1,0

0,0

Batch 4; Comparison @ -10C

2 4 6 8 10 12 14 16 18 20

6,0
5,0
4,0
3,0
2,0
1,0

0,0

Batch 6; Comparison @ -10C

Irradiated up 0.9 1012 n/cm2 Irradiated up 1.2 1012 n/cm2 Irradiated up 2.3 1012 n/cm2

§ 5 SiPMs/batch “passively” neutron irradiated @ Dresden § For Mu2e, the max n-flux in SiPM area is of around (4 )x10^10 n/cm^2 § Safety Factor 3(MC)x5(Years)x2(Prod) = 1.2 10^12n/cm^2 § Max Idark current for operation of 2 mA è Requires cooling of -10 C, Lower operation overvoltage to Vop-3V (for the MU2E serie) , 20% of PDE relative loss

NP19 - Mu2e Calorimeter, R.Donghia

SLIDE 26

FEE ADC/DAC test up to 120 krad

q all analog parts of Amplifier and HV regulator are rad-hard but LT ADC/DAC of digital sector suffering from 10-15 krad up à new rad-hard TI ADC/DAC identified q PCB with TI ADC/DAC completed q 1 week of gamma irradiation done @ end of January up to 110 krad

June 11, 2019 25

SET

4 5 8 8 4 1 1 2 3 4 5 6 7 8 9 500 1000 1500 2000 2500 3000 3500

DAC SET

Difference A0-A1 [mV]

SET

1
2
1
4
7
8
7
6
5
4
3
2
1

500 1000 1500 2000 2500 3000 3500

DAC SET

Difference D2-D1 [mV]

Maximum deviation of ADC and DAC before and after irradiation
Consistent with TI specifications

DAC ADC

NP19 - Mu2e Calorimeter, R.Donghia

SLIDE 27

Mechanical integration:FEE+MB cabling

June 11, 2019 26

à FEE rad-hard chip format frozen à New cable selected to handle rad-hard ADC/DAC à Routing of FEE-MB cables in CAD model à First realistic estimate of cable lengths, weights 4 km cables , 55 kg/disk à Final mockup in progress

NP19 - Mu2e Calorimeter, R.Donghia

SLIDE 28

Electronics – Slice test

q Next round of measurement with TID for FEE planned for end of November in Italy. Also FPGA polar fire for digital board will be tested q Version v3 of FEE and V2 of DIRAC are under way to get them much radiation dose harder q Aiming for CRR for electronics in spring 2019 q Vertical slice test planned with FEE-v2 and Dirac-V1 in December with 20 channels of Module-0 SLICE test with FEE-V1 and CAEN digitizer

June 11, 2019 27

TMu_4 Entries 16 Mean 0.00625 Std Dev 0.01053 [ns] µ 2 − 1.5 − 1 − 0.5 − 0.5 1 1.5 2 Entries / 25 ps 1 2 3 4 5 6 7 8 TMu_4 Entries 16 Mean 0.00625 Std Dev 0.01053 TMu_4 Entries 16 Mean 0.00625 Std Dev 0.01053 Starting values 1st iteration 2nd iteration 3th iteration 4th iteration 5th iteration

TMu_4

Entries 16082

Energy [MeV] 20 40 60 80 100 120 140 160 Entries / 0.5 MeV 50 100 150 200 250 300 350 400

Entries 16082 3 crystals 4 crystals 5 crystals

Figure 7.22 NP19 - Mu2e Calorimeter, R.Donghia

SLIDE 29

SG crystal + Hamamatsu SiPM + FEE Optical coupling in air.

22Na source
TRG: small scintillator readout by a PMT
Study distance effect for air-coupling

Single channel slice test

Time [ns]

80 100 120 140 160 180 200 220

Amplitude [mV]

5 10 15 20 25

Hamamatsu 4 - DIstance from Crystal 0 mm 1 mm 2 mm

~ 10% loss

Cosmic ray test à 2 SiPMs readout
TRG: crystal between 2 small scintillators

2 SiPMs

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SLIDE 30

Single channel Cosmic Rays Test

TRG time resolution ~ 170 ps
Constant fraction method used
Pulse height correction applied

(slewing)

After jitter subtraction: SiPM 1 – σT ~ 330 ps SiPM 2 – σT ~ 340 ps T(SiPM1 - SiPM2)/2 à ~ 215 ps @ ~ 23 MeV energy deposition (MIP energy scale from Na22 source peak) Timing result well compares with old tests: à Reduced light output/SiPM (22 vs 30 pe/MeV) à 2 SiPMs/crystal à LY of 44 vs 30 à 215 ps (now) vs 250 ps (old).

Entries 727 Constant 6.2 ± 133.6 Mean 0.0161 ± 0.1234 Sigma 0.012 ± 0.429

Time [ns]

3
2
1

1 2 3 Entries / 25 ps 20 40 60 80 100 120 140

Entries 727 Constant 6.2 ± 133.6 Mean 0.0161 ± 0.1234 Sigma 0.012 ± 0.429

SiPM 1 - SiPM 2 Σ June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 29

SLIDE 31

Pre-production test: Crystals (2)

Few samples per vendor have been exposed both to ionizing dose and neutrons

Irradiation test up to 100 krad
Requirement:

normalized LY after 10/100 krad > 85/60%

Radiation Induced Noise (RIN) @ 1.8 rad/h required is < 0.6 MeV
All 72 samples tested. All OK apart some Amcrys crystals that

do not satisfy the required limit

Negligible LY and LRU variation after 1.6 x 1012 n1MeV/cm2 integrared flux
Neutron RIN is also smaller than the one from dose

Most crystals have LY larger than 100 p.e./MeV after 100 krad (40% max. loss), promising a robust CsI calorimeter

85% 60%

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 30

SLIDE 32

]

2

/cm

1MeV

Integrated flux [n 100 200 300 400 500 600 700 800

9

10 I [mA] 10 20 30 40 50 60

Entries 102900 Mean 90.04 Mean y 33.18 RMS 63.51 RMS y 33.26

Time [ns] 50 100 150 200 Amplitude [mV] 20 40 60 80 100 120 140 160

Entries 102900 Mean 90.04 Mean y 33.18 RMS 63.51 RMS y 33.26 Entries 102900 Mean 90.09 Mean y 60.63 RMS 63.51 RMS y 110.6

Time [ns] 50 100 150 200 Amplitude [mV] 100 200 300 400 500

Entries 102900 Mean 90.09 Mean y 60.63 RMS 63.51 RMS y 110.6

Pre-production SiPMs

150 sensors: 3×50 Mu2e pre-production SiPMs from Hamamatsu, SenSl and AdvanSiD

3×35 were fully characterized for all six cells in the array

Gain Mu2e custom silicon photosensors: à 2 arrays of 3 6 x 6 mm2 UV-extended SiPMs: total area (12x18) mm2 The readout series configuration reduces the overall capacitanceàfaster signals ~ 150 V i1≈ i2 ≈ i3 Ctot ≈ C1/3

6x6 mm2 K1 A1

A1-1 A1-2

Single cell of 6 x 6 mm2 Series of 3 cells

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 31

We need to cool down SiPMs at 0 ° Neutron test Hamamatsu SenSl AdvanSiD

SLIDE 33 Entries 1633 / ndf 2 χ 29.69 / 21 Constant 7.2 ± 225.1 Mean 0.0054 ± 0.1647 Sigma 0.0043 ± 0.2131

t [ns] ∆ 2 − 1.5 − 1 − 0.5 − 0.5 1 1.5 2 Entries / (0.075 ns) 50 100 150 200 250

Entries 1633 / ndf 2 χ 29.69 / 21 Constant 7.2 ± 225.1 Mean 0.0054 ± 0.1647 Sigma 0.0043 ± 0.2131

Module 0 SiPM-vendors comparison

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 32

Time [ns] 160 180 200 220 240 260 280 300 320 340 Amplitude [mV] 50 100 150 200

10%max

T

90%max

=T

rise

T = 29 ns

rise

Hamamatsu - T = 38 ns

rise

SensL - T = 37 ns

rise

AdvanSiD - T

Ebeam = 100 MeV Energy fluctuation CF discriminator

Entries 1857 / ndf 2 c 18.68 / 23 Constant 7.0 ± 237.8 Mean 0.0054 ± 0.1584 Sigma 0.0042 ± 0.2313

t [ns] D 2

1.5
1
0.5
0.5

1 1.5 2 Entries / (0.075 ns) 50 100 150 200 250

Entries 1857 / ndf 2 c 18.68 / 23 Constant 7.0 ± 237.8 Mean 0.0054 ± 0.1584 Sigma 0.0042 ± 0.2313

σT ~ 115±2ps SensL σT ~ 106.5±2.1ps

Entries 1531 / ndf

2

19.56 / 15 Constant 7.6 240.9 Mean 0.0049 0.1664 Sigma 0.0035 0.1874

t [ns] 1.5 1 0.5 0.5 1 1.5 Entries / (0.075 ns) 50 100 150 200 250

Entries 1531 / ndf

2

19.56 / 15 Constant 7.6 240.9 Mean 0.0049 0.1664 Sigma 0.0035 0.1874

σT ~ 93.5±2ps AdvanSiD

Hamamatsu

SLIDE 34

Mu2e

Charged Lepton Flavor Violation

CLFV

strongly suppressed in SM: BR ≤10-54 à Observation indicates New Physics

CLFV@Mu2e:µ-

e conversion in a nucleus field à discovery sensitivity on many NP models

Goal:

104 improvement w.r.t. current limit (SINDRUM II) (@ 90% CL, with ~ 1018 stopped muons in 3 years of running)

Contact dominated Loop dominated

µ-e conversion in the presence of a nucleus

< 8 x 10-17

Nuclear captures of muonic Al atoms

µ e Al

arXiv: 1303.4907 June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 33

SLIDE 35

Module 0 Event selection

June 11, 2019 NP19 - Mu2e Calorimeter, R.Donghia 34

Noise width in the new charge increase linearly with the number of crystals added

SLIDE 36

Module 0 Event selection

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SLIDE 37

Module 0 Event selection

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SLIDE 38

Module 0 Event selection

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20 40 60 80 100 [MeV]

MC

E 200 400 600 800 1000 1200 1400 Q [pC]

/ ndf

2

χ 89.91 / 4 p 0.02236 ± 12.47 / ndf

2

χ 89.91 / 4 p 0.02236 ± 12.47 pC to MeV = 1 / p = 0.0802

SLIDE 39

PId

38

With a CRV inefficiency of 10-4 an additional rejection factor of ~ 200 is needed to have < 0.1 fake events from cosmics in the signal window

A rejection factor of 200 can be achieved with ~ 95% efficiency for CE

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SLIDE 40

Calorimeter Trigger

Calo info can provide additional trigger capabilities in Mu2e:
Calorimeter seeded track finder
Factorized into 3 steps: hit pre-selection, helix serach and track fit
ε ~ 95% for background rejection of 200
Standalone calorimeter trigger that uses only calo info
Ε ~ 65% for background rejection 200

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SLIDE 41

Calorimeter seeded track finder

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SLIDE 42

Calorimeter radiation damage

Calorimeter radiation dose driven by beam

flash (interaction of proton beam on target)

Dose from muon capture is x10 smaller
Dose is mainly in the inner radius
Highest dose ~10 krad/year
Highest n flux on crystals ~ 2×1011 n/cm2/year
Highest n flux on SiPM ~ 1011 n1MeVeq/cm2/year
Qualify crystals up to

~ 100 krad, 1012 n/cm2

Qualify SiPM up to

~ 1012 n1MeVeq/cm2

This includes a safety factor

f 3 for a 3 year run

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SLIDE 43

Calorimeter performances

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SLIDE 44

Calorimeter mechanics

Mu2e Collaboration, November 2013

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SLIDE 45

Calorimeter Readout electronics

Mu2e Collaboration, November 2013

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SLIDE 46

Three years run Expectation by full Simulation

Mu2e Collaboration, November 2013

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SLIDE 47

CLFV Lagrangian

Mu2e Collaboration, November 2013 µN→eN µ→eγ µ→eee Loops dominate for κ << 1 Contact terms dominate for κ >> 1 κ µN→eN µ→eγ µ→eee

Λ (TeV)

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