BTeV Pixel Silicon Detector

1
BTeV Pixel Silicon Detector

• Test beam results 1999-2000
• J.A. Appel, J.N. Butler, G. Cardoso, H. Cheung,
  G. Chiodini D.C. Christian, E.E. Gottschalk, B.K.
  Hall, J. Hoff, P. A. Kasper, R. Kutschke,
  S.W.Kwan, A. Mekkaoui, R. Yarema, and S.
  Zimmermann
• Fermi National Accelerator Laboratory
• C. Newsom - University of Iowa
• A. Colautti, D. Menasce, and S. Sala -
  INFN(Milan)
• R. Coluccia and M. Di Corato - Universita di
  Milano
• M.Artuso and J.C. Wang Syracuse University
• Talk given by G. Chiodini Fermilab
• Genova - Pixel 2000 - June 5-9, 2000

2
Overview

• Test beam setup
• 5 pixel plane tested
• SSD telescope and DAQ
• Test beam results
• Pixel Calibration
• Charge collection
• Charge-sharing
• Spatial resolution
• Four plane pixel telescope
• Conclusions

3
Setup 5 pixel planes tested
Samples of FPIX0 and FPIX1 readout chips
bump-bonded to ATLAS sensor prototypes
50x400 mm2 cells
30 mm pitch indium bumps
FPIX0 64x12cells 8 bit external ADC
FPIX1 160x18cells 2 bit internal FADC

• ST1-CiS p-stop
• ST2-CiS p-spray
• Bonded active area 3.2x4.4mm2

• Two ST1-Seiko p-stop
• ST2-Seiko p-spray
• Bonded active area 8x6.8mm2

4
Setup 5 pixel planes tested
FPIX0 Inner Board
Analog Buffer
8 bit ADC
Pixel detector Light protected
Close-up middle station
5
Setup SSD telescope and DAQ
Magnet
DAQ
E T H E R N E T

• I/O Board
• - Controls and Initializes 4 Pixel
  readout chips
• - GPIB controller HV, thresholds, and
  pulser
• Automatic pixel calibration

VME COMPUTER
I/O BOARD
STAR
TFIB
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Resultspixel calibration - pulse generator
Qth2500400e- Qnoise10613e-
Qnoise,ADC40096e- Dynamics 1.5MIP
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Results Pixel calibration - X ray sources
Vth0 Threshold knob
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Results Charge collection
1MIP30100e-
Single chip Tile 1 CiS p-stop
1MIP21500e-
Single chip Tile 2 CiS p-spray
9
Results charge-sharing
Track inclination
Diffusion
Qth2500e- Vbias-140V
Delta rays emission
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Results charge-sharingBias voltage
ST1 CiS FPIX0 detector
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Results charge-sharingThreshold
ST1 CiS FPIX0 detector
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Results spatial resolutionGaussian width
ST1 CiS FPIX0 detector
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Results spatial resolutionComparison between
detectors
Qth2500e- Qth2200e- Qth3780e-
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Results spatial resolutionBias voltage
ST1 CiS FPIX0 detector
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Results spatial resolutionThreshold
ST1 CiS FPIX0 detector
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Results spatial resolution2D spatial resolution
x
ST1 CiS FPIX0 detector
y
Sigma 4.650.10
Sigma 12.90.26
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Results spatial resolutionNon-Gaussian
resolution function
CS1 and track angle lt 10 degs Square convoluted
with a Gaussian
CSgt1 track angle lt 10 degs and all CS track angle
gt 10 degs Gaussian power law

• Non-Gaussian part
• 15 of events half in the constant
• term and half in the tails
• power law with an exponent ³2

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Four plane pixel telescope
2.2mm thick diamond target
Interaction vertex in the target
Thousands triggered multiple interactions events
Interaction vertex in pixel plane
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Conclusions

• The FPIX-type FE performs well as expected and
  needed
• GREAT data sample to gain operational experience
  with PSDs (3M useful events)
• Primary features of results are clear
• Very good resolution at all angles
• 3 ADC bits will be enough for BTeV
• Parameterization of the non-Gaussian tails used
  in L1 trigger MC simulations
• The BTeV multiplicity is easily handled by 50mm x
  400mm pixels