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Update on Analysis of
FNAL TB09
Jianchun Wang
for the group
Syracuse UnivesityJan 29th ,2010
Testbeam Team at FNAL
June 2008: Tony Affolder, Marina Artuso, Alessandra Borgia, Lars Eklund, Karol Hennessy, Gwen Lefeuvre, Ray Mountain, Abdi Noor, Chris Parkes, Sheldon Stone, Jianchun Wang
April 2009: Marina Artuso, Alessandra Borgia, Torkjell Huse, David Hutchcroft, Ray Mountain, Jianchun Wang
Pixel system: David Christian (FNAL), Bruce Knapp (Nevis Lab), Jianchun Wang
More from remote
01/29/10 Jianchun Wang 2
301/29/10 Jianchun Wang
Introduction
PixelVELO
Pixel
YX YX
120 GeV proton beam
Pixel
Y
Scint
RR( )F
X
Z
Y
The system and analysis procedure: Independent DAQ systems for Pixel & VELO, sharing trigger signals. Events are matched offline. Tracks are reconstructed from pixel hits and fit to straight lines, multiple scattering is treated
separately. Pixel stations/modules are aligned within its own system. Velo sensors are aligned with respect to the pixel tracks. Tracks, corresponding Velo event IDs and alignment
parameters are saved in tracking data files. Pixel tracking data are fed to Vetra for VELO analysis.
Non-irradiated N-type R sensor (R/ f pair) Charge sharing & resolution for different pitches and track angles. Presented at 10/19/09 TREC meeting. Some plots are included here for comparison.
Differentially irradiated N-type & P-type R sensors (RR pair) Most probable charge vs irradiation particle fluence ( presented at 12/07/09 VELO meeting), some are updated
here. Most probable charge for different bias HVs. Detection efficiency and resolution.
Just
a re
mind
er
Basic on Charge Distributions
The FE electronics were under-powered, resulting in low gain. Most probable charge ~16 ADC instead of ~40.
Constant thresholds (seed=3.6, inclusion=1.8) are used (noise ~ 0.9 ADC counts). Thresholds are low enough to study irradiated sensors.
Gain differences are partially corrected using header heights.
Only hits that match with pixel tracks are looked at, to reduce the influence from uncertainty of noise hits.
Charge distributions are fit to Landau convoluted with Gaussian. The width of Gaussian is fixed to an average value so as to reduce the uncertainty on Landau MP.
In some cases there are shoulders/tails on low side that were not well understood. Fits are at peak areas. Fit range affects MP obtained from fit. MP represents, but not completely, the charge collection efficiency.
01/29/10 Jianchun Wang 4
Charge (ADC counts)
Sensor Charge Collection
Jianchun Wang 5
Tracks at 0-8 degrees, detector biased at 500 V.Hit map determined by pixel tracks that matche with VELO hits.
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= – Y
X (
mm
)
N-type
= + Y
X (
mm
)
P-type
?
?
MP Charge At Different HVs
Jianchun Wang 6
Bias Voltage (V)
500 400 300200 100 50
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N-type P-type
No HV scanned for middle part due to tight schedule.
It is difficult to extract correct MP when MP is close to threshold.
Comparing Different Electronics Settings
Jianchun Wang 7
N-typeKazu setting
P-typeKazu setting
N-typeChris setting
P-typeChris setting
optimized for sensors after irradiation.
Optimized for current running in the pit.
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biased at 500 V
Detection Efficiency
01/29/10 Jianchun Wang 8
Due to the trigger scheme and different DAQ clock frequencies for the two systems, tracks seen by pixel and VELO are not necessarily the same.
Pixel tracks are matched with hits from one sensor (± 200 mm) to ensure this is a real track and seen by VELO.
We then look at the other sensor to see if there is hit that matches the track. The detection efficiencies are thus determined.
Beam profiles are not guaranteed to be the same for different conditions so the weight of dead areas changes for different condition runs.
A dead chip and few dead strips and certain border areas are removed.
In this way, the detection efficiencies reflect more precisely the effect of irradiation fluences and/or bias voltages.
Cleanup of Dead Strip & Borders
Jianchun Wang 9
X (mm)
Y (
mm
)
X (mm)
Y (
mm
)
N-sensor
P-sensor
N-sensor
P-sensor
Remove 6 bad
strips & borders
Remove 4 bad
strips & borders
hit position expectation that are unmatched
01/29/10
!
!
Detection Efficiency
Jianchun Wang 10
N-typeKazu setting
P-typeKazu setting
Normal incident tracks
Biased at 500 V
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Not from 0
Detection Efficiency
Jianchun Wang 11
N-typeKazu setting
P-typeKazu setting
All angles
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Bias Voltage (V)
500 400 300200 100 50
Detection Efficiency
Jianchun Wang 12
N-typeChris setting
P-typeChris setting
All angles
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?
For Resolution Study
Jianchun Wang 13
Track Effective Angle (degree)
Select regions Y< –16 mm & Y > 16 mm.
Angles: 0-2, 2-4, 6-8 degrees
Pitches: 64-70, 70-80, 80-90, 90-100 mm
Y (mm)
Pitc
h ( m
m )
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Resolution vs Pitch
Jianchun Wang 14
Normal Incidence (0.5)
R of R/ f pairN-type
0-2 degree
P-type0-2 degree
Fully irradiated (Kazu)
Fully irradiated (Chris)
Non-irradiated (Kazu)
Fully irradiated (Kazu)
Non-irradiated (Kazu)
Non-irradiated (Chris)
Error not fully estimated
R of R/f pair (Chris, 0 degree)
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Resolutions are obtained through Gaussian fit to residual distributions, not just RMS due to bkg hits.
Tracking errors are removed.
Charge Sharing vs Pitch
Jianchun Wang 15
R of R/ f pair
N-type0-2 degree
P-type0-2 degree
Fully irradiated (Kazu)
Fully irradiated (Chris)
Non-irradiated (Kazu)
Non-irradiated (Kazu)
Fully irradiated (Kazu)
Non-irradiated (Chris)
Error not estimated
R of R/f pair (Chris, 0 degree)
Angle ( )-0.5 – 0.52.5 – 3.56.5 – 7.5
10.5 – 11.5
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Resolution vs Pitch
Jianchun Wang 16
N-type
P-type
Error not fully estimated
R of R/ f pair
Angle ( )- 0.5 – 0.52.5 – 3.56.5 – 7.5
10.5 – 11.5
Irradiated Fully None
Angle (degree)0-22-46-8
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Center of Residual vs HV
Jianchun Wang 17
N-typefully-irradiated6-8 degree tracks
64 – 70 mm
90 – 100 mm
80-90 mm
70 – 80 mm
Naïve interpretationMax difference ~150tan(8) = 21 mm
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Center of Residual vs HV
Jianchun Wang 18
64 – 70 mm
90 – 100 mm80-90 mm
70 – 80 mm
P-typenon-irradiated6-8 degree tracks
01/29/10
Full depletion voltage ~ 110 V
Summary
Data on irradiated sensors are analyzed.
Most probable charge, detection efficiency, charge sharing and resolution are measured for different pitch, HV and irradiation dose.
Paper draft is on the way.
More ideas may come up while producing paper draft.
Some systematic errors already added, more will be included.
Suggests and contributions are welcome.
01/29/10 Jianchun Wang 19
Comparison Between N- and P-type Sensor
Jianchun Wang 20
P-type
N-type
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More on N-type Sensor
Jianchun Wang 21
Artificial parameter from MP so that the shape looks more like the irradiation profile
Slopes in the transition region exhibit small discrepancy.
N-type sensor
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MP vs HV
Jianchun Wang 22
N-type P-type
Non-irradiated
Vdep = 117±7 V
irradiated
irradiated
Fit with a naïve function
Non-irradiated
From non-irradiated
Vdep = 771±43 VVdep = 1218±96 V
01/29/10