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LHCb VELO Testbeam at Fermilab

LHCb VELO Testbeam at Fermilab . Jianchun Wang Syracuse University. Track Data Format. A: Raw Track Magic cookie (01 02 03 04) I*4 Length of the block I*4 Block type (6) I*4 Number of hits I*4 Tbdb ID ( Hit 1) I*4 Chip ID I*4 Local X F*4 Local Y F*4

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LHCb VELO Testbeam at Fermilab

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  1. LHCb VELO Testbeamat Fermilab Jianchun Wang Syracuse University

  2. Track Data Format • A: Raw Track • Magic cookie (01 02 03 04) I*4 • Length of the block I*4 • Block type (6) I*4 • Number of hits I*4 • Tbdb ID ( Hit 1) I*4 • Chip ID I*4 • Local X F*4 • Local Y F*4 • Expected X resolution F*4 • Expected Y resolution F*4 • … (Hit 2) • FF FF FF 00 I*4 • C: Pixel Track Event for VELO • Magic cookie (01 02 03 04) I*4 • Length of the block I*4 • Block type (7) I*4 • Trigger event ID I*4 • Matched VELO event ID I*4 • Distance from trigger jump I*4 • Number of tracks I*4 • Number of hits (Track 1) I*4 • Chi2 of fit F*4 • Projected X at DUT F*4 • Projected Y at DUT F*4 • Track slope X F*4 • Track slope Y F*4 • Projected X error at DUT F*4 • Projected Y error at DUT F*4 • … ( Track 2) • FF FF FF 00 I*4 • B: VELO Alignment • Magic cookie (01 02 03 04) I*4 • Length of the block I*4 • Block type (8) I*4 • Number of VELO sensors I*4 • X offset of sensor 1 F*4 • Y offset of sensor 1 F*4 • Angle around X axis of sensor 1 F*4 • Angle around Y axis of sensor 1 F*4 • Angle around Z axis of sensor 1 F*4 • … • FF FF FF 00 I*4 For pixel alignment: AAAAAA… For VELO study: BCCCCC… Jianchun Wang

  3. Event Matching Between Pixel and VELO Best match Offset Trigger Count Offset Accu. Number of VELO Hits pix_090420_111844 • There are fake trigger or trigger inefficiency, that are different in the two systems. • Showing up in data ~ few counts difference over the whole run (~50K triggers). • To determine and correct this trigger jump we rely on matching between VELO hit and pixel track. • Out of 115 runs 81 have this problem, totals 349 jumps. • For some studies events around the jump should be excluded. Jianchun Wang

  4. Pixel Trigger Issue Run pix_090420_094446 Before After Pixel Trigger ID (100 bins) • The pixel trigger ID should be continuously incremented number starting from 0. • 15 files with pixel trigger issues that the trigger number are not continuous. • In 3 runs, few trigger pockets were not sent out, resulting a jump of one count or few. This does not affect event matching between pixel and Velo systems. • In 13 runs, there were fake trigger pockets sent out (total 63 times). Because the trigger counter has cycle of 4096. Count smaller than in the previous event results in an increment of 4096. This was corrected manually. Jianchun Wang

  5. Summary Of Status • Pixel and VELO events are matched in all runs. • Wrongly assembled VELO events are fixed. We need to regenerate date files of these runs. • Pixel alignment is good enough for many studies. • More precise alignment is on the way. • Tracks of reasonable alignment are generated. • Tool is written to handle tracks. • Noise, efficiency, resolution, and TELL1 algorithm cross-checking are on-going. Jianchun Wang

  6. Data Sets Jianchun Wang

  7. Residual On the 5th Station Ncol = 1 Ncol > 1 Different Scale Number of Entries (Arb. Unit) Nrow = 1 Nrow > 1 Measurement – Track Projection (mm) Binary readout 5 pixel stations Simulated through iterations  track proj. error ~ 4.9 mm Jianchun Wang

  8. Track Probability Issue Tracks (arb. Unit) Exclude Ncol = 1 Prob (c2, ndof) Expect Tracks (arb. Unit) Non-gaussian Seen Uniform dist for Ncol=1 Gaussian for the rest Prob (c2, ndof) With multiple scattering Jianchun Wang

  9. Tracking Error 5 pixel stations X Log ( number of tracks ) Y • Multiple scattering contributes 1.7-2.1mm to track projection error. • One can select events of better tracking error. • Measurements of Ncol=1 improve track projection precision, although distort the track probability distribution. Tracking Error from Pixel (mm) Calculated without multiple scattering Jianchun Wang

  10. Look at R/F Data Matched Hits Y ( mm) Signal (ADC) Pixel coverage X ( mm) We took data at nominal 0, 4, 8, 12 degrees rotated around horizontal axis. The effective angle is smaller due to concentric strips. Effective Track Angle (degree) Jianchun Wang

  11. Charge Sharing (I) Strip pitch (40, 50) mm R sensor of R/f pair Nstrip = 2 Nstrip = 1 All pitches & track angle Percentage of Hits Nstrip = 3 Effective Track Angle (Degree) Range: angle0.5 Seed threshold = 6 ADC ~ 9.6 Ke Side threshold = 3 ADC ~ 4.8 Ke Cluster Size Jianchun Wang

  12. Charge Sharing (II) Pitch ( mm) 40 – 50 50 – 60 60 – 70 70 – 80 80 – 90 90 – 100 Angle (  ) -0.5 – 0.5 2.5 – 3.5 6.5 – 7.5 10.5 – 11.5 (Nstrip > 1) / N total (%) (Nstrip > 1) / N total (%) Effective Track Angle (Degree) Strip Pitch (mm) R/f data is split into 1 of angle & 10 mm of pitch sub-samples. Sub-samples of 0, 3, 7 and 11 are with reasonable large statistics. Jianchun Wang

  13. Velo Resolution Measurement • Resid = 18.0 mm <strk> = 5.1 mm Nevent = 12.5K • <Resid = 19.2 mm <strk> = 8.0 mm Nevent = 175K Rvelo – Rtrack (mm) Rvelo – Rtrack (mm) Error < 6 mm Tracking Error from Pixel (mm) Trk error = (pixel)1.85mm (multi-scatt.) <strk> = quadratic average over all trks To improve tracking precision one has to sacrifice statistics. Jianchun Wang

  14. Resolution vs Pitch R sensor of R/f pair Angle (  ) - 0.5 – 0.5 2.5 – 3.5 6.5 – 7.5 10.5 – 11.5 Preliminary !. Velo Hit Resolution (mm) Tracking projection uncertainty removed from resolution. Tracking precision is determined for each point ( ~ 4.7–5.4 mm). Error bar represents only statistic error. Linear charge weighting, eta-correction not applied yet. Strip Pitch (mm) Seed threshold = 6 ADC ~ 9.6 Ke Side threshold = 3 ADC ~ 4.8 Ke Jianchun Wang

  15. Tracking Precision Angle (  ) - 0.5 – 0.5 2.5 – 3.5 6.5 – 7.5 10.5 – 11.5 For each track the projections on Velo and projected errors in both X and Y directions are calculated using the corresponding pixel resolutions. R and error in R is calculated from X/Y. For each sample (point), the projection error is quadratically averaged over all tracks used. Projection error due to multiple scattering is ~1.85 mm obtained from simulation. The alignment error is to be determined. R Error From Track Projection (mm) Strip Pitch (mm) Jianchun Wang

  16. Resolution vs Track Angle Pitch ( mm) 40 – 50 50 – 60 60 – 70 70 – 80 80 – 90 90 – 100 Velo Hit Resolution (mm) 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. Effective Track Angle (Degree) Jianchun Wang

  17. The Eta Curve One strip shift due to tracking precision Only Strip N+1 has Charge All pitches & angles Nstrip = 1 removed Cluster Fraction Only Strip N has Charge Track Hit Fraction Center of Strip N Center of Strip N+1 Jianchun Wang

  18. The Eta Curves Of Small Pitches Angle=3 Angle=0 Pitch = (40-50) mm Nstrip = 1 removed Cluster Fraction Angle=11 Angle=7 Track Hit Fraction Jianchun Wang

  19. The Eta Curves Of Small Pitches Angle=3 Angle=0 Cluster Fraction Angle=11 Angle=7 Track Hit Fraction Pitch = (40-50) mm Cluster fraction=0 or1 correspond to nstrip=1, indicating how charge sharing varies with hit position. Jianchun Wang

  20. Uniform Irradiation: 6 VELO year eq. Useful for resolution, efficiency & S/N vs pitch, angle (x-axis rotations) Varying Irradiation: 0-6 VELO year eq. Useful for resolution, efficiency & S/N vs. pitch and dose Uniform Irradiation: 0 VELO year eq. Useful for resolution & S/N vs pitch, angle (x-axis rotations) Jianchun Wang 20

  21. RR Module: Position of irradiation spots Tell1 8 n-in-p Tell1 5 n-in-n Top Beam high irr low irr Bottom • Beam at the top • 500V on each sensor RR Files used: • RR_0deg_Top_latency_0x17_delay_40ns_Kazu_HV500-20090427-081938.mdf Jianchun Wang

  22. Jianchun Wang

  23. N in N Jianchun Wang 23

  24. Header Height Vs V2.5 T = ~ 2 °C, Kazu setting T = 4 - 8 °C, Kazu setting T = 23 - 27 °C, Kazu setting T = ~ 27 °C, Chris setting Kazu’s setting, at FNAL header height = 28.48 ± 1.48 Obtained from one run. Uncertainty of value is about 0.1-0.2. Sigma indicates spread among 64 links. Chris’s setting, at FNAL header height = 29.34 ± 1.12 We tried to find out what value V2.5 was during testbeam. Header height is also affected by T and electronics setting, not just V2.5 alone. Jianchun Wang

  25. Header Height vs Temperature H = 50.934 – 0.1754 T(C) V2.5 at nominal value Kazu setting Jianchun Wang

  26. VELO Containers Jianchun Wang

  27. Transient Event Store for Emulator • Normal data from each hybrid are stored in an array of 2048 = 64x32 elements, indexed by either the electronics channel or the strip ID. • In emulator dummy elements are added to mimic 4 FPGAs. The overall size is 2304 = (64+8)x32. • Before reordering data are stored in the order of electronics channel. And 2x32 dummies are added after each 512=16x32. ( DecodedADC, SubtracedPedADCs, FIRCorrected, and ADCMCMSCorrected). • The pedestal are still stored in an array of 2048 (SubtractedPed). • After channel reordering data are stored in the order of strip ID. For R sensor 2x32 dummies are added after each 512 strips (16x32). For F sensor each sector occupies 18x32 elements with inner strips the beginning of first 6x32 and outer strips the beginning of next 12x32 in the table (ADCReordered, ADCCMSuppressed). Jianchun Wang

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