The Cylindrical GEM Detector of the KLOE-2 Experiment - - PowerPoint PPT Presentation

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The Cylindrical GEM Detector of the KLOE-2 Experiment - - PowerPoint PPT Presentation

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The Cylindrical GEM Detector of the KLOE-2 Experiment Instrumentation for Colliding Beams 2017 Alessandro Di Cicco, Roma Tre University February 27 th March 3 rd For the KLOE-2 Collaboration Novosibirsk, Russia March 2nd 2017 - A. Di Cicco

slide-1
SLIDE 1

The Cylindrical GEM Detector

  • f the KLOE-2 Experiment

Alessandro Di Cicco, Roma Tre University For the KLOE-2 Collaboration Instrumentation for Colliding Beams 2017 February 27th – March 3rd Novosibirsk, Russia

March 2nd 2017 - A. Di Cicco - INSTR17 1

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SLIDE 2

2 March 2nd 2017 - A. Di Cicco - INSTR17

Th The KLOE-2 2 experiment

KLOE-2 is presently taking data at DA𝜚NE 𝜚-factory e+e- collider at √s = 1019.4 MeV

[Talk by D. Domenici] Physics Program [EPJ C68 (2010)]

  • KS, η, ηS rare decays
  • γγ physics
  • Quantum Interferometry
  • Dark Photon searches
slide-3
SLIDE 3

3 March 2nd 2017 - A. Di Cicco - INSTR17

Th The KLOE-2 2 experiment

Physics Program [EPJ C68 (2010)]

  • KS, η, ηS rare decays
  • γγ physics
  • Quantum Interferometry
  • Dark Photon searches

Calorimeter System

  • ECAL - Pb/Scint Fibers w PMTs
  • LET - LYSO+SiPMs
  • HET - Scint+PMTs
  • QCALT - W+ Scint Tiles w SiPMs (Quads)
  • CCALT - LYSO+APDs (Low-beta)

[Talk by F. Curciarello]

HET 11 m from IP LET QCALT CCALT ECAL KLOE-2 is presently taking data at DA𝜚NE 𝜚-factory e+e- collider at √s = 1019.4 MeV

[Talk by D. Domenici]

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SLIDE 4

4 March 2nd 2017 - A. Di Cicco - INSTR17

Th The KLOE-2 2 experiment

Physics Program [EPJ C68 (2010)]

  • KS, η, ηS rare decays
  • γγ physics
  • Quantum Interferometry
  • Dark Photon searches

Calorimeter System

  • ECAL - Pb/Scint Fibers w PMTs
  • LET - LYSO+SiPMs
  • HET - Scint+PMTs
  • QCALT - W+ Scint Tiles w SiPMs (Quads)
  • CCALT - LYSO+APDs (Low-beta)

Tracking System

  • DC – 3.7x4 m2 He:Iso 90:10 gas mixture
  • IT – 4 cylindrical GEM tracking devices

Superconductive Magnet

  • 0.52 T axial magnetic field

[Talk by F. Curciarello]

HET 11 m from IP LET IT QCALT CCALT ECAL DC KLOE-2 is presently taking data at DA𝜚NE 𝜚-factory e+e- collider at √s = 1019.4 MeV

[Talk by D. Domenici]

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SLIDE 5

5 March 2nd 2017 - A. Di Cicco - INSTR17

Th The Inner Tracker of KLOE-2

  • Improve VTX reconstruction at IP
  • First batch ever of GEM foils produced with a

single-mask etching developed by CERN-TE-MPE-EM for large area foils

  • 70 cm active length
  • 650 µm strips two-view readout
  • 25k channels GASTONE FEE [NIM A 732 (2013)]
  • 1.6k HV channels
  • FEE DAQ system [JINST 08 T04004 (2013)]
  • 1200 gas gain
  • 2% X0 material budget

The 4 cylindrical-GEM layers of the IT 36 cm 41 cm 31 cm 26 cm Inner Tracker

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SLIDE 6

6 March 2nd 2017 - A. Di Cicco - INSTR17

Th The Inner Tracker of KLOE-2

  • Improve VTX reconstruction at IP
  • First batch ever of GEM foils produced with a

single-mask etching developed by CERN-TE-MPE-EM for large area foils

  • 70 cm active length
  • 650 µm strips two-view readout
  • 25k channels GASTONE FEE [NIM A 732 (2013)]
  • 1.6k HV channels
  • FEE DAQ system [JINST 08 T04004 (2013)]
  • 1200 gas gain
  • 2% X0 material budget

The 4 cylindrical-GEM layers of the IT 36 cm 41 cm 31 cm 26 cm

Each layer is a triple-GEM detector with 3/2/2/2 mm layout

Inner Tracker

slide-7
SLIDE 7

7 March 2nd 2017 - A. Di Cicco - INSTR17

Th The Inner Tracker of KLOE-2

  • Improve VTX reconstruction at IP
  • First batch ever of GEM foils produced with a

single-mask etching developed by CERN-TE-MPE-EM for large area foils

  • 70 cm active length
  • 650 µm strips two-view readout
  • 25k channels GASTONE FEE [NIM A 732 (2013)]
  • 1.6k HV channels
  • FEE DAQ system [JINST 08 T04004 (2013)]
  • 1200 gas gain
  • 2% X0 material budget

The 4 cylindrical-GEM layers of the IT 36 cm 41 cm 31 cm 26 cm

650µm 600µm ~ 30°

Kapton/Copper flexible multilayer readout circuit built at CERN TE-MPE-EM, 300 µm tot thickness X-view: longitudinal strips V-view: connection of pads through conductive vias and common backplane Each layer is a triple-GEM detector with 3/2/2/2 mm layout

Inner Tracker

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SLIDE 8

8 March 2nd 2017 - A. Di Cicco - INSTR17

IT IT Operation Optimization

26 cm

  • Cosmic-ray muon DC tracks extrapolated to IT
  • Take closest reconstructed IT cluster

to expected position from DC track ε = 94% single-view @ Gain = 12000 Good compromise between IT clustering efficiency and detector operation with colliding beams

Dips in occupancy due to GEM foil micro-sector structure 10% improvement with EIND=6kV/cm

Gain 5000 10000 15000 20000 Efficiency 0.5 0.6 0.7 0.8 0.9 1.0

/ ndf

2

χ 3.855 / 2 p0 0.007135 ± 0.9771 p1 0.04709 ±

  • 0.5051

p2 ± 0.07 p3 ± 0.0004 p4 ±

  • 10

/ ndf

2

χ 3.855 / 2 p0 0.007135 ± 0.9771 p1 0.04709 ±

  • 0.5051

p2 ± 0.07 p3 ± 0.0004 p4 ±

  • 10

Efficiency X-view Layer#1 EIND = 6 kV/cm

ε

Cosmic-ray muons

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SLIDE 9

9 March 2nd 2017 - A. Di Cicco - INSTR17

IT IT Operation Optimization

26 cm

  • Cosmic-ray muon DC tracks extrapolated to IT
  • Take closest reconstructed IT cluster

to expected position from DC track ε = 94% single-view @ Gain = 12000 Good compromise between IT clustering efficiency and detector operation with colliding beams

  • Bhabha scattering events selected using

DC track information Preliminary two-view efficiency measurement with IT operating during collisions in agreement with cosmic-ray data analysis

Dips in occupancy due to GEM foil micro-sector structure 10% improvement with EIND=6kV/cm

Gain 5000 10000 15000 20000 Efficiency 0.5 0.6 0.7 0.8 0.9 1.0

/ ndf

2

χ 3.855 / 2 p0 0.007135 ± 0.9771 p1 0.04709 ±

  • 0.5051

p2 ± 0.07 p3 ± 0.0004 p4 ±

  • 10

/ ndf

2

χ 3.855 / 2 p0 0.007135 ± 0.9771 p1 0.04709 ±

  • 0.5051

p2 ± 0.07 p3 ± 0.0004 p4 ±

  • 10

Efficiency X-view Layer#1 EIND = 6 kV/cm

ε

Cosmic-ray muons Efficiency vs z z (cm) Bhabha scattering

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SLIDE 10

10 March 2nd 2017 - A. Di Cicco - INSTR17

IT IT Operation with Co Collisions

26 cm

GEM voltages decrease if current is above limit (5000 nA)

  • ther

voltages unchanged

Online monitoring – IT operations with collisions

HV CAEN A1515CG Test on Layer#3

Old HV scheme: 7 independent channels referred to ground, possible discharge propagation among GEM

stages when current saturates on

  • ne electrode

New HV scheme: 7 independent floating channels, HV CAEN A1515CGsuccessfully tested and installed in Sep 2016 on all layers for safer

  • peration

Single voltage adjustment allowed

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SLIDE 11

11 March 2nd 2017 - A. Di Cicco - INSTR17

IT IT Operation with Co Collisions

26 cm

GEM voltages decrease if current is above limit (5000 nA)

  • ther

voltages unchanged

Online monitoring – IT operations with collisions

HV CAEN A1515CG Test on Layer#3

Online monitoring – IT current of innermost layer

time IT L1 Current (nA)

Current spikes over threshold may occur at beam injections without discharges propagating through GEM stages Old HV scheme: 7 independent channels referred to ground, possible discharge propagation among GEM

stages when current saturates on

  • ne electrode

New HV scheme: 7 independent floating channels, HV CAEN A1515CGsuccessfully tested and installed in Sep 2016 on all layers for safer

  • peration

Single voltage adjustment allowed

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SLIDE 12

12 March 2nd 2017 - A. Di Cicco - INSTR17

IT IT Calibration Strategy

26 cm

  • 1. NON-RADIAL TRACKS The angle

formed by a track and the radialE- field direction introduces shift & spread of the e- cloud

  • 2. MAGNETIC FIELD 0.52 T B-field
  • rthogonalto GEM stages E-fields:

shift and larger spread of the electron cloud

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SLIDE 13

13 March 2nd 2017 - A. Di Cicco - INSTR17

IT IT Calibration Strategy

26 cm

  • 1. NON-RADIAL TRACKS The angle

formed by a track and the radialE- field direction introduces shift & spread of the e- cloud

  • 2. MAGNETIC FIELD 0.52 T B-field
  • rthogonalto GEM stages E-fields:

shift and larger spread of the electron cloud

Cosmic-ray muon data acquired with B-field OFF

Calibration of Non-radial track effect Select DC tracks crossing IT at 2 points Shifts and rotations to align the IT

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SLIDE 14

14 March 2nd 2017 - A. Di Cicco - INSTR17

IT IT Calibration Strategy

26 cm

  • 1. NON-RADIAL TRACKS The angle

formed by a track and the radialE- field direction introduces shift & spread of the e- cloud

  • 2. MAGNETIC FIELD 0.52 T B-field
  • rthogonalto GEM stages E-fields:

shift and larger spread of the electron cloud

Cosmic-ray muon data acquired with B-field OFF

Calibration of Non-radial track effect Select DC tracks crossing IT at 2 points Shifts and rotations to align the IT

Cosmic-ray muon data acquired with B-field ON

Calibration of Non-Radial track & B-field effects Corrections, Shifts and rotations from B-field OFF sample

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SLIDE 15

15 March 2nd 2017 - A. Di Cicco - INSTR17

IT IT Calibration Strategy

26 cm

  • 1. NON-RADIAL TRACKS The angle

formed by a track and the radialE- field direction introduces shift & spread of the e- cloud

  • 2. MAGNETIC FIELD 0.52 T B-field
  • rthogonalto GEM stages E-fields:

shift and larger spread of the electron cloud

Cosmic-ray muon data acquired with B-field OFF

Calibration of Non-radial track effect Select DC tracks crossing IT at 2 points Shifts and rotations to align the IT

Cosmic-ray muon data acquired with B-field ON

Calibration of Non-Radial track & B-field effects Corrections, Shifts and rotations from B-field OFF sample

Bhabha scattering events

Check calibration of Non-radial track & B-field effects Corrections , Shifts and rotations from cosmic-ray muon

data analysis with B-field ON sample

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SLIDE 16

16 March 2nd 2017 - A. Di Cicco - INSTR17

Th The road to the First Calibration of the IT T

26 cm

Very challenging, never done before.

Cosmic-ray muons B OFF – Layer#4 Starting point 1.5 mm width Cosmic-ray muons B OFF – Layer#4 After calibration 450 µm width

Entries 10993 / ndf

2

χ 295 / 66 Const Broad 12.1 ± 197.7 Offset Broad 0.005440 ± 0.006381 Sigma Broad 0.0091 ± 0.2817 Const Narrow 44.0 ± 2745 Offset Narrow 0.00074 ± 0.01573 Sigma Narrow 0.00088 ± 0.05694

x residuals (cm)

  • 1
  • 0.5

0.5 1 1.5 2 500 1000 1500 2000 2500 3000

Entries 10993 / ndf

2

χ 295 / 66 Const Broad 12.1 ± 197.7 Offset Broad 0.005440 ± 0.006381 Sigma Broad 0.0091 ± 0.2817 Const Narrow 44.0 ± 2745 Offset Narrow 0.00074 ± 0.01573 Sigma Narrow 0.00088 ± 0.05694

Cosmic-ray muons B ON – Layer#4 After calibration 560 µm width Bhabha scattering B ON – Layer#4 After calibration 400 µm width

Large improvement

  • btained with first set
  • f calibration constants

Calibration strategy undergoing refinement to further improve present results

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SLIDE 17

17 March 2nd 2017 - A. Di Cicco - INSTR17

IT IT Calibration wi with Bh Bhabha Sc Scattering Events - Pr Present Status

26 cm

Present results from Bhabha scattering events analysis validates our strategy.

Layer#4 400 µm Layer#3 400µm Layer#1 500 µm Layer#3 350 µm

Residual distributions contains also contribution from DC

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SLIDE 18

18 March 2nd 2017 - A. Di Cicco - INSTR17

Va Validation of Integrated Tracking IT + DC

26 cm

  • Start with DC reconstructed tracks
  • Add IT clusters and reconstruct IT+DC tracks

I.P.

DC Inner Wall IT Layers

1st hit of DC track

Beam Pipe

Kalman Filter IT+DC

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SLIDE 19

19 March 2nd 2017 - A. Di Cicco - INSTR17

Va Validation of Integrated Tracking IT + DC

26 cm

  • Start with DC reconstructed tracks
  • Add IT clusters and reconstruct IT+DC tracks
  • Validation with Bhabha scattering events and

KSàπ+π- events

  • Use 1st set of calibration constants

I.P.

DC Inner Wall IT Layers

1st hit of DC track

Beam Pipe

Kalman Filter IT+DC

slide-20
SLIDE 20

20 March 2nd 2017 - A. Di Cicco - INSTR17

Va Validation of Integrated Tracking IT + DC

26 cm

  • Start with DC reconstructed tracks
  • Add IT clusters and reconstruct IT+DC tracks
  • Validation with Bhabha scattering events and

KSàπ+π- events

  • Use 1st set of calibration constants

I.P.

DC Inner Wall IT Layers

1st hit of DC track

Beam Pipe

Kalman Filter IT+DC

  • Select KSàπ+π- selected events
  • Simple vertex finder based on minimum

distance between tracks

  • Compare IT+DC to DC-only simple vertex

Calibration constants to be refined and integrated tracking undergoing validation Simple vertexing is exploited.

DC IT+DC KSàπ+π-

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SLIDE 21

21 March 2nd 2017 - A. Di Cicco - INSTR17

Co Conclusions

26 cm

  • KLOE-2 Inner Tracker is the first cylindrical GEM detector ever used in high energy physics

experiments

  • Big efforts have been devoted to operate this novel detector with colliding beams while

keeping good performance

  • First detector alignment and calibration successfully performed using cosmic-ray muon and

Bhabha scattering data

  • Challenging task to be accomplished. Never done before.
  • IT+DC tracking with Kalman filter & vertexing in official KLOE-2 framework
  • Integrate tracking IT+DC exploits first set of calibration constants
  • Bhabha scattering and KSàπ+π- events used for validation tests
slide-22
SLIDE 22

March 2nd 2017 - A. Di Cicco - INSTR17 22

slide-23
SLIDE 23

23 March 2nd 2017 - A. Di Cicco - INSTR17

In Inner Tracker Construction – Ma Main Ste teps

26 cm

Novel technique entirely developed at Frascati Laboratories of INFN

1) 3 large-area GEM foils are spliced together with 3 mm overlap for gluing. 2) 3 anode/readout foils are spliced together without overlap. Head-to-head joints glued with 6 cm kapton adhesive strips. 3) Electrodes rolled on a cylindrical mold 4) The GEM mold is fixed at the bottom of the insertion machine. Readout plane is fixed at the top. Electrodes are axially aligned with a precision of 0.1mm/1.5m

slide-24
SLIDE 24

24 March 2nd 2017 - A. Di Cicco - INSTR17

IT IT Operation Point Optimization – “E “Edge Effect”

26 cm

GEM TOP: 40 HV micro-sectors GEM BOTTOM: 4 HV sectors Short-circuit distribution per micro-sector

  • Segmentation of the GEM foils causes a

distortion of the effective gain

  • Higher gains at the borders of HV sectors
  • Observed also by ALICE, COMPASS-THGEM
  • Solution: increase GEM hole diameter
slide-25
SLIDE 25

25 March 2nd 2017 - A. Di Cicco - INSTR17

La Layer#1 Parameters s – St Standard Operation with Collisions

26 cm Time Current (nA) Time Voltage (V) Time Fields (kV/cm)

slide-26
SLIDE 26

26 March 2nd 2017 - A. Di Cicco - INSTR17

IT IT Calibration Validation with Bh Bhabha Sc Scattering Events - Pr Present Status

26 cm

Present results from Bhabha scattering events analysis validate our strategy and suggest how to improve.

Layer#4 Layer#2 Layer#1 Layer#3 Residuals x Residuals y Residuals z Residuals x Residuals y Residuals z Residuals x Residuals y Residuals z Residuals x Residuals y Residuals z