Presentation on theme: "Collection Of Plots for A Testbeam Paper. List of Possible Plots R/Phi resolution, charge sharing, noise etc. Noise performance and few Landau distributions."— Presentation transcript:
List of Possible Plots R/Phi resolution, charge sharing, noise etc. Noise performance and few Landau distributions Testpulse MP/Irradiation fluence vs position MP/Irradiation fluence vs position for different bias voltages For full irradiated area, MP vs HV to extract full depletion voltage Detection efficiency at certain threshold. Charge sharing comparison at full vs at none, and transition region Resolution comparison at full vs at none, and transition region. Ballistic deficit with one pitch bin. Jianchun Wang2
10/19/09Jianchun Wang4 Charge Sharing (I) Seed threshold 5.4 Ke Side threshold 2.7 Ke Strip pitch (40, 50) m N strip = 1 N strip = 2 N strip = 3 R sensor of R/ pair Range: angle 0.5 Cluster Size Percentagge Side threshold ~ 2 × noise
10/19/09Jianchun Wang5 Charge Sharing (II) Pitch ( m) 40 – 50 50 – 60 60 – 70 70 – 80 80 – 90 90 – 100 R/ data is split into 1 of angle & 10 m of pitch sub-samples. Sub-samples of 0 , 3 , 7 and 11 are with reasonable large statistics. Angle ( ) -0.5 – 0.5 2.5 – 3.5 6.5 – 7.5 10.5 – 11.5 Seed threshold 5.4 Ke Side threshold 2.7 Ke
Charge Sharing With Different Thresholds (I) Jianchun Wang6 pitch (40, 50) m, angle (–0.5, 0.5) N strip = 1 N strip = 2 N strip = 3 Angle ( ) -0.5 – 0.5 2.5 – 3.5 6.5 – 7.5 10.5 – 11.5 Seed threshold = 4 ADC Side threshold = 2 ADC Approximate conversion for R/ 22.5 Ke / 15 ADC = 1.5 Ke/ADC
Charge Sharing With Different Thresholds (II) Jianchun Wang7 pitch (40, 50) m, angle (–0.5, 0.5) N strip = 1 N strip = 2 N strip = 3 Angle ( ) -0.5 – 0.5 2.5 – 3.5 6.5 – 7.5 10.5 – 11.5 Seed threshold = 6 ADC Side threshold = 3 ADC Approximate conversion for R/ 22.5 Ke / 15 ADC = 1.5 Ke/ADC
10/19/09Jianchun Wang 8 The Eta Curve Eta curve plot – the relationship between charge sharing and track hit position. It can be generated in two ways. Method one (Thanks to suggestion from Jan Buytaert): 1)Find track projected hit position on VELO plane. 2)Find the two adjacent strips between the centers of which that the track hits. 3)Calculated charge sharing before applying threshold. Method two (useful in hit position reconstruction): 1)Applying thresholds and form clusters. 2)Select two- or more-strip clusters that matched with track. 3)Calculate charge sharing. Track Hit Fraction Only Strip N has Charge Cluster Fraction = Only Strip N+1 has Charge Center of Strip N Center of Strip N+1
Eta Curve Correction 10/19/09Jianchun Wang9 Pitch = 40 – 50 m Angle = (-0.5 , 0.5 ) Nstrip = 2 only Fit eta profile and correct R VELO measurement. Track Hit Fraction Cluster Fraction Profile Fit to pol3 = 11.7 = 10.1 R VELO – R track ( m )
10/19/09 Jianchun Wang10 Resolution vs Pitch R sensor of R/ pair Preliminary ! Angle ( ) - 0.5 – 0.5 2.5 – 3.5 6.5 – 7.5 10.5 – 11.5 Tracking precision is removed from the hit resolution. Tracking precision is determined at each point (~6 m). Error bar includes: Statistic error from fit ~ 0.2–0.5 m, except for few points. Different fitting methods ~ 0.1–0.5 m. Guestimated uncertainty on alignment error & tracking precision ~ 0.5 m. Contribution: ~0.1–0.4 m. Seed threshold 5.4 Ke Side threshold 2.7 Ke
Comparison 10/19/09Jianchun Wang11 Source Resol @ 40 m Pitch/sqrt(12) 11.5 m ACDC3 ~ 9.2 m TED Fit ~ 10.6 m FNAL Fit 8.1 0.6 m Normal Incidence ( 0.5 ) Preliminary ! TED result was produced by Silivia Borghi and presented by Kazu Akiba at the Florence LHCb week Low momentum track, momentum not measured. Multiple scattering effect is not removed precisely. If resolution is determined from RMS of residual instead of fit, then the projection to 40 m is 9.6 0.6 m
10/19/09Jianchun Wang12 Resolution vs Track Angle Effective track angle is determined in plane perpendicular to the strip. Sub-samples of 0 , 3 , 7 and 11 are with reasonable large statistics. Other angles are due to concentric strip, thus with small amount of hits. Pitch ( m) 40 – 50 50 – 60 60 – 70 70 – 80 80 – 90 90 – 100 Large statistics For discussion purpose only Worse than testbeam 2004 results (ref: lhcb-2007-151)
N-type Sensor Charge Collection Jianchun Wang15 The relative position between irradiation profile and sensor Y is adjusted according to the center of two transition regions ( Position = Yprofile – 39.3 mm). N-type sensor is flipped (Position = -Y). X VELO (mm) Y VELO (mm) Hit map determined by tracking All angles
P-type Sensor Charge Collection Jianchun Wang16 X VELO (mm) Y VELO (mm) Hit map determined by tracking 1 bad beetle chip The sudden drop after 30 mm is unexpected. It is very unlikely that the irradiation profile is wrong. Normal incident track only
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 Wang17 Charge (ADC counts)
Sensor Charge Collection Jianchun Wang1801/29/10 = – Y X (mm) N-type = + Y X (mm) P-type ? ? Tracks at 0-8 degrees, detector biased at 500 V. Hit map determined by pixel tracks that matches with VELO hits.
N-type MP Charge At Different HVs Jianchun Wang19 HV (V) 500 400 300 200 100 50 Sum of all angles Some points need further work
P-type MP Charge At Different HVs Jianchun Wang20 HV (V) 500 400 300 200 100 50 Some points need further work
Comparison Between N- and P-type Sensor Jianchun Wang21 P-type N-type
Comparing Different Electronics Settings Jianchun Wang22 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. biased at 500 V
More on N-type Sensor Jianchun Wang23 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
MP vs Y for Different X Slices Jianchun Wang24 X Slices (–5, ) (–10, –5) (–20, –10) (, –20) X flipped
Phi Value of Sector Borders Jianchun Wang25 The VELO alignment wrt pixel tracks has very loose constraint in phi. Check if this is the source of the shift in MP vs position for different X slices. Look at phi of matched pixel hits for each sector. Borders are clear. Fit to error function. The average edge value of the neighboring border is consistent with (+0.0017 and +0.0016 for N-type and P-type respectively). Borders between sectors 0&1, 2&3 are consistent with 3/4 and 5/4 . The maximum difference is ~ 0.003 corresponding to shift of 0.12 mm at R=42mm. Ruled out N-type, Sector 1 Edge = 3.1472 Sigma = 0.0016 N-type, Sector 2 Edge = 3.1395 Sigma = 0.0008 (rad) Number of Matched Hits
Detection Efficiency 01/29/10Jianchun Wang26 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 Wang27 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 Wang28 N-type Kazu setting P-type Kazu setting Normal incident tracks Biased at 500 V 01/29/10 Not from 0
N-type Sensor Charge Sharing Jianchun Wang29 Largest strip ADC value of each cluster Low tail due to large cluster size Y = (–42, –32) mmY = (–32, –18) mm Y = (32, 42) mmY = (18, 32) mm
P-type Sensor Charge Sharing Jianchun Wang30 Largest strip ADC value of each cluster Low tail due to large cluster size Y = (–42, –32) mmY = (–32, –18) mm Y = (32, 42) mmY = (18, 32) mm
Detection Efficiency Jianchun Wang32 N-type Chris setting P-type Chris setting All angles 01/29/10 ?
Detection Efficiency Vs Mp Jianchun Wang33 N-type P-type Biased at 500 V Detection efficiency is determined by 1.charge collected (MP) 2.charge sharing (cluster size) 3.seed threshold (constant ADC)
Detection Efficiency Vs MP for Different HV Jianchun Wang34 N-type Kazu setting P-type Kazu setting All angles Bias Voltage (V) 500 400 300 200 100 50
MP vs HV Jianchun Wang35 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
For Resolution Study Jianchun Wang36 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 Wang37 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 Wang38 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) Angle ( ) -0.5 – 0.5 2.5 – 3.5 6.5 – 7.5 10.5 – 11.5
Center of Residual vs HV Jianchun Wang40 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
Center of Residual vs HV Jianchun Wang41 64 – 70 m 90 – 100 m 80-90 m 70 – 80 m P-type non-irradiated 6-8 degree tracks Full depletion voltage ~ 110 V
Inefficiency Issue Jianchun Wang42 The window is ± 200 m for reference plane hit with pixel tracks. If noise hit gets in due to this window, the efficiency would be lower. The window is tighten to ± 100 m, for reference plane. The efficiency difference is negligible. 200 m might be too tight for DUT.
Non-perpendicular Beam For Irradiation Jianchun Wang43 Irradiation profile offset Old= 39.3 mm New= 36.8 mm X Slices (–5, ) (–10, –5) (–20, –10) (, –20) Angle = 0.251 Before rotation After rotation X Y Position Position* N-type
MP vs Y for Different X Slices Jianchun Wang44 X Slices (–5, ) (–10, –5) (–20, –10) (, –20) N-type P-type
Sensor Charge Collection Jianchun Wang4501/29/10 = – Y(rotate) X (mm) N-type = + Y (rotate) X (mm) P-type ? ? Tracks at 0-8 degrees, detector biased at 500 V. X Y Position X Y
Pixel VELO Pixel YX 120 GeV proton beam Pixel Y Scint RR( X Z Y ~ 1 m Pixel X/Y VELO Pixel Y Pixel X/Y