Patrick Spradlin, SCIPP trip to LLU, May 2, 2001 Detector Characteristics.
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Patrick Spradlin, SCIPP trip to LLU, May 2, 2001 Detector Characteristics
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Transcript of Patrick Spradlin, SCIPP trip to LLU, May 2, 2001 Detector Characteristics.
Patrick Spradlin, SCIPP trip to LLU, May 2, 2001
Detector Characteristics
Patrick Spradlin, SCIPP trip to LLU, May 2, 2001
Patrick Spradlin, SCIPP trip to LLU, May 2, 2001
Detector Details
Patrick Spradlin, SCIPP trip to LLU, May 2, 2001
Vital Statistics
• Overall detector area: 6.4 cm by 6.4 cm• Wafer thickness: 400 m• Silicon: n-type substrate, p-type strips• Large substrate resistivity: 5-8 k• Number of strips: 320• Strip pitch: 194 m• Strip width: 50 m• AC coupled strip readout
Patrick Spradlin, SCIPP trip to LLU, May 2, 2001
Some Considerations in Estimating Energy from TOT
• Detector: Energy deposited => Charge Q in detector– Landau Distribution of deposited energy
– Shot noise
• Preamplifier and Front End Electronics– Threshold Calibration
– Charge Saturation: plateau in TOT vs. Input charge response
• Controller and Readout => TOT• Estimated charge Q => Estimated particle energy
Patrick Spradlin, SCIPP trip to LLU, May 2, 2001
Landau Energy Deposition, 400 m thick detector
0
0.02
0.04
0.06
0.08
0.1
0.12
0 10000 20000 30000 40000 50000 60000
Deposited Charge (fC)
Pro
bab
ility
/222
.5 f
C
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Inte
grat
ed P
rob
abili
ty
30 MeV
25 MeV
20 MeV
15 MeV
35 MeVIntegrated Probability
Curves
Binned DistributionCurves
Patrick Spradlin, SCIPP trip to LLU, May 2, 2001
Landau Energy Deposition, 300 m thick detector
0
0.02
0.04
0.06
0.08
0.1
0.12
0 10000 20000 30000 40000 50000 60000
Deposited Charge (fC)
Pro
ba
bil
ity
/22
2.5
fC
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Inte
gra
ted
Pro
ba
bil
ity
30 MeV diff
25 MeV diff
20 MeV diff
15 MeV diff
35 MeV
Integrated ProbabilityCurves
Binned DistributionCurves
Patrick Spradlin, SCIPP trip to LLU, May 2, 2001
Deposited Charge vs. Energy of Incident Proton*
0
10000
20000
30000
40000
50000
60000
70000
80000
10 15 20 25 30 35 40
Proton Energy (MeV)
Ma
xim
um
Lik
elih
oo
d D
epo
site
d C
ha
rge
(fC
)
400 um thicknes
300 um thickness
*Based on Monte Carlo Simulation
Patrick Spradlin, SCIPP trip to LLU, May 2, 2001
Leakage Current
• Possible source of detector noise– Minimized with care. Usually a small noise
source– Shot noise. Mainly affects long shaping time.
• Temperature dependence:– Leakage current doubles for each 7°C rise in
detector temperature
• Bias voltage dependence:– Illustrated on following chart
Patrick Spradlin, SCIPP trip to LLU, May 2, 2001
I-V Characteristics
HKM Factory Data, Detector 312.Factory Data for other 3 detectors
similar.25°C
SCIPP Data, Apr. 25, 200124°C
Patrick Spradlin, SCIPP trip to LLU, May 2, 2001
Energy DepositionComparison of Landau distribution (theoretical line)
with ToT data from GLAST
Patrick Spradlin, SCIPP trip to LLU, May 2, 2001
Two MIP EventsComparison of theoretical and observed energy depositionfor possibility of 2 tracks passing through the same strip
