Update on Analysis of FNAL TB09 Jianchun Wang for the group Syracuse Univesity Jan 29 th,2010.
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Update on Analysis of FNAL TB09 Jianchun Wang for the group Syracuse Univesity Jan 29 th,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 01/29/10Jianchun Wang2
01/29/10Jianchun Wang3 Introduction Pixel VELO Pixel YX 120 GeV proton beam Pixel Y Scint RR( 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/ 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 reminder
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. 01/29/10Jianchun Wang4 Charge (ADC counts)
Sensor Charge Collection Jianchun Wang5 Tracks at 0-8 degrees, detector biased at 500 V. Hit map determined by pixel tracks that matche with VELO hits. 01/29/10 = – Y X (mm) N-type = + Y X (mm) P-type ? ?
MP Charge At Different HVs Jianchun Wang6 Bias Voltage (V) 500 400 300 200 100 50 01/29/10 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 Wang7 N-type Kazu setting P-type Kazu setting N-type Chris setting P-type Chris setting optimized for sensors after irradiation. Optimized for current running in the pit. 01/29/10 biased at 500 V
Detection Efficiency 01/29/10Jianchun Wang8 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 m) 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 Wang9 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 Wang10 N-type Kazu setting P-type Kazu setting Normal incident tracks Biased at 500 V 01/29/10 Not from 0
Detection Efficiency Jianchun Wang12 N-type Chris setting P-type Chris setting All angles 01/29/10 ?
For Resolution Study Jianchun Wang13 Track Effective Angle (degree) Select regions Y 16 mm. Angles: 0-2, 2-4, 6-8 degrees Pitches: 64-70, 70-80, 80-90, 90-100 m Y (mm) Pitch ( m ) 01/29/10
Resolution vs Pitch Jianchun Wang14 Normal Incidence ( 0.5 ) R of R/ pair N-type 0-2 degree P-type 0-2 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 pair (Chris, 0 degree) 01/29/10 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 Wang15 R of R/ pair N-type 0-2 degree P-type 0-2 degree Fully irradiated (Kazu) Fully irradiated (Chris) Non-irradiated (Kazu) Fully irradiated (Kazu) Non-irradiated (Chris) Error not estimated R of R pair (Chris, 0 degree) Angle ( ) -0.5 – 0.5 2.5 – 3.5 6.5 – 7.5 10.5 – 11.5 01/29/10
Center of Residual vs HV Jianchun Wang17 N-type fully-irradiated 6-8 degree tracks 64 – 70 m 90 – 100 m 80-90 m 70 – 80 m Naïve interpretation Max difference ~150 tan(8 ) = 21 m 01/29/10
Center of Residual vs HV Jianchun Wang18 64 – 70 m 90 – 100 m 80-90 m 70 – 80 m P-type non-irradiated 6-8 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. 01/29/10Jianchun Wang19
Comparison Between N- and P-type Sensor Jianchun Wang20 P-type N-type 01/29/10
More on N-type Sensor Jianchun Wang21 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 01/29/10
MP vs HV Jianchun Wang22 N-type P-type Non-irradiated V dep = 117±7 V irradiated Fit with a naïve function Non-irradiated From non-irradiated V dep = 771±43 V V dep = 1218±96 V 01/29/10