1 / 53

Tracking results from Au+Au test Beam

Tracking results from Au+Au test Beam. Jochen Markert For the Tracking group. Status. DST gen0: Almost full calibration of all detectors alignment of all detectors (Shower done by hand) NOW: second iteration of calibration and alignment (new procedures by Vladimir)

timothyf
Download Presentation

Tracking results from Au+Au test Beam

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Tracking results from Au+Au test Beam Jochen Markert For the Tracking group

  2. Status DST gen0: • Almost full calibration of all detectors • alignment of all detectors (Shower done by hand) NOW: • second iteration of calibration and alignment (new procedures by Vladimir) • Overall improved tracking performance • Kalman Filter almost ready • MDC dE/dx to be done • Investigations of tracking parameters ongoing

  3. Improvements S3: tracks +8% chi2 -10% wires +2.3% S5: tracks +17% chi2 -25% wires +11.5% S6: tracks +10% chi2 -31% Wires +12% V. & O. Pechenov

  4. Vertex Day 224 Field • Vertex fit for field runs uses 2 inner MDCs simultaneously • Sigma ~ 1.3 mm V. & O. Pechenov

  5. Vertex Day 227 No Field • Vertex fit for no field runs uses 4 MDCs simultaneously • Better resolution compared to field on runs • Sigma ~ 1.1 mm V. & O. Pechenov

  6. Cluster Search And Fitting

  7. Number of Layers in Segments • Solid line for cluster • Dashed line for fit • Cluster search requires 10 layers at minimum • Almost the same number of layers in cluster for MIPS and NonMIPS • Less wires accepted in fit for outer segment (average loss 2 layers) compared to inner segment (average loss 1 layer)

  8. Number of Wires in Segment • Solid line for cluster • Dashed line for fit • Cluster search required 10 layers at minimum • Less wires accepted in fit for outer segment (average loss 2 layers) compared to inner segment (average loss 1 layer)

  9. Number of Layers in Segment Required layers in segment: >= 10 layers >= 11 layers =12 layers

  10. Number of Wires in Segment Required wires in segment: >= 10 wires >= 11 wires >= 12 wires >= 13 wires >= 14 wires >= 15 wires >= 16 wires >= 17 wires

  11. Track Fit

  12. Drift Velocity vs. Electric Field • Drift velocity of Ar/CO2 higher compared to Ar/i-butane • No real plateau for Ar/CO2 • Drift velocity very low at low electric field values for Ar/CO2

  13. Drift Velocity Contours for MDCI Ar/i-butane Ar/CO2 • Strong inhomogeneous drift velocity contour for Ar/CO2

  14. Fit Deviation vs Distance from Wire Deviation = tmeasured – tcalculated • Systematic deviation visible • Origin: cal1/cal2 ? • Needs to be investigated separately for each wire

  15. Fit Deviation vs Distance from Wire • Systematic effect stronger for NonMIPS compared to MIPS

  16. Drift Time Resolution • Resolution shows strong detoriation close to the sense wire • Different shape for MDCI compared to other MDCs • Better resolution for NonMIPS

  17. Front end Setting Comparison

  18. Evaluating 3 Scenarios • Aug 15  • spike rejection of TDCs in plane II = 23 ns • Aug 16 - 19  • from august 16, 13:42:00 on the spike rejection of TDC in plane II changed to 13 ns • Aug 17 • 13:21:41 – 13:24:12 two runs with high threshold settings (0x60) and spike rejection of TDCs = 13 ns

  19. Plane I, Sector 3, Layer 1 • Rich structures in the measured drift data • Question: Contain to additional structures “good” measurements with wrong time measurement ? T.Galatyuk

  20. Plane II, Sector 3, Layer 1; 15 && 17-19 August Black curves = Day 227 Color = Day 229 – 231  spike rejection of TDCs has been changedfrom 23 ns to 13 ns T.Galatyuk

  21. Plane I, Sector 3, Layer 1 Thr.>0x30 Thr.>0x60 • Higher threshold reduce additional structures T.Galatyuk

  22. Plane I, Sector 3, Layer 1 Factor of 10 suppression of the small ToT satellite T.Galatyuk

  23. The combination of low thresholds (0x30) and 23 ns spike suppression of TDCsseems to be a better choice? T.Galatyuk

  24. Momentum Distributions RPC ToF • High spike rejection + low threshold or low spike rejection + low threshold seems to be featured T.Galatyuk

  25. Mass Distributions RPC ToF p p d 3He t T.Galatyuk

  26. Number of Wires in Cluster for different Front end Settings • MIPS selected • Low threshold + high spike rejection results in more wires in the cluster compared to standard setting

  27. Number of Wires in Cluster for different Front end Settings • NonMIPS selected • Low threshold + high spike rejection results in more wires in the cluster compared to standard setting • Less improvement compared to MIPS

  28. Number of Wire in Segment for different Front end Settings • MIPS selected • Low threshold + high spike rejection results in more wires in the cluster compared to standard setting

  29. Number of Wire in Segment for different Front end Settings • MIPS selected • Low threshold + high spike rejection results in more wires in the cluster compared to standard setting • Less improvement compared to MIPS

  30. Efficiency Studies • Fully reconstructed tracks: • inner + outer segment fitted • Runge-Kutta fit succeeded • Matched with Meta hit • NonMIPS : beta < 0.6 • MIPS : beta > 0.8

  31. particle  y x ToT as Function of Impact Angleinto the Drift Cell NonMIPS • Integration over distance from wire • 5 degree angle bins • Second bump at large ToT for MDCI due to strong drift velocity variation for ArCO2 angle angle

  32. ToT as Function of Impact Angleinto the Drift Cell MIPS • Second bump at large ToT almost vanished

  33. particle  Cell Efficiency from Segment Fit • Impact angle and distance from wire known from segment fit • Only accepted wires are taken into account • Reference are wires which should have given a signal • Efficiency limited due to segment fit ? • Low values MDCIV ? • Structures in MDCI ? 70% 70% 75% 58%

  34. Cell Efficiency from Segment Fit • Better efficiency compared to MIPS • Still the same questions as before 73% 82% 80% 58%

  35. Cell Efficiency from Segment Fit • Difference between efficiency of MIPS and NonMIPS

  36. Cell Efficiency from Cluster • Impact angle and distance from wire known from segment fit • wires from cluster are taken into account • Reference are wires which should have given a signal • Efficiency not limited due to segment fit, but noise or double hits are counted as “good” 80% 84% 90% 84%

  37. Cell Efficiency from Cluster • MDCIV now at high efficiency • Conclusion: segment fit looses wires due to noise or wrong measurements (hardware, geometry,cal1, cal2) 80% 90% 92% 90%

  38. Cell Efficiency from Cluster • Difference between efficiency of MIPS and NonMIPS

  39. Cell Efficiency results

  40. Layer Efficiency • Layer efficiency calculated from clusters • Only clusters are selected which contain no multiple used wires • Event multiplicity 10-30 selected, max multiplicity per sector < 8 tracks • Long spike rejection + low threshold seems to be the most efficient combination T.Galatyuk

  41. Probabilities T.Galatyuk

  42. Comparison between Au+Au and Ar+KCl • Layer efficiencies comparable • 40 degree layers show lower efficiencies T.Galatyuk

  43. Some layers show same efficiency structures • The complete chamber has been build new. Front end electronics could be the reason T.Galatyuk

  44. Thank you!

  45. Time (from 0 to 100 ns) vs.Distance to wire (from 0 to 2.5 mm) Ar/i-butane Ar/CO2

  46. Number of layers in module

  47. Number of wires in module

  48. 13 ns, 0X38 23 ns, 0X38 23 ns, 0X60

  49. Velocity vs. Momentum x charge RPC TOF

  50. Time-of-flight spectrun in RPC b > 0 b < 0

More Related