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STAR Time of Flight software & analyses

STAR Time of Flight software & analyses. Frank Geurts Rice University. Outline. TOF Timing HPTDC chip Calibration for HPTDC Non-Linearity TOF Performance Monitoring Online Monitoring Prompt Analyses TOF Offline Analysis Fast Offline QA Overall Layout Matching Algorithm

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STAR Time of Flight software & analyses

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  1. STAR Time of Flightsoftware & analyses Frank Geurts Rice University

  2. Outline • TOF Timing • HPTDC chip • Calibration for HPTDC Non-Linearity • TOF Performance Monitoring • Online Monitoring • Prompt Analyses • TOF Offline Analysis • Fast Offline QA • Overall Layout • Matching Algorithm • Physics Production Chain and Calibration • TOF Offline resources/organization • Summary & Outlook Hanghzou Workshop on STAR TOF

  3. TOF timing: HPTDC★ • Timing based on CERN HPTDC chip • Operated in the Very High Resolution Mode: • external clock input 40MHz • 11bit coarse timing, 25ns • internal Phased Lock Loop 8x 40MHz • 3bit, 3.125ns • internal Delay Locked Loop of 32 cells • 5bit, 98ps • internal 4 R-C delay lines • 2bit, 24.4ps • 21-bit timing information • 8 MRPC channels per HPTDC chip • 3 HPTDC chips per TDIG board • 8TDIGs per TOF tray ★) High Performance Time to Digital Converter LSB MSB PLL bits (bin width 3.125ns) DLL bits (bin width 98 ps) R-C bits (bin width 24.4 ps) Coarse time(bin width 25ns, 11 bits) Hanghzou Workshop on STAR TOF

  4. TOF Timing Data • Timing based on Leading Edge (LE) MRPC signal • set by a discriminator on the TINO board • Signal-height correction (slewing) based on Time-over-Threshold (ToT) • measure the Trailing Edge (TE) of MRPC signal • ToT is time difference between LE and TE; proportional to signal height; • slewing correction based on offline calibration • see today’s presentation by Ming Shao • HPTDC has an intrinsic non-linearity • due to e.g. process variation • requires a per-channel calibration • once determined, expect no changes Hanghzou Workshop on STAR TOF

  5. HPTDC Non-Linearity • HPTDCs come with a three sources of non-linearity • unequal bin widths in RC-tapped delay lines • unequal bin widths in DLL • noise coupling from the logic network (40MHz) into the sampling clock network (320MHz) • Higher level tests show clock feedthrough (#3) dominates • periodicity is 1024 bins (25ns) • Differential Non-Linearity (DNL): • determine statistical bin width using a code density test: • apply uniform random distribution w.r.t. TDC clock • compare measured vs. expected #entries 1024 1024 #entries Bin number Hanghzou Workshop on STAR TOF

  6. Integral Non-Linearity Calibration • HPTDC integral non-linearity (INL): • INL(n) = Σi=1..n DNL(i), • where DNL(i)= [Nexp – Nmeas(i)] / Nexp • INL correction determined for all TOF HPTDC channels • Full TOF Barrel: 120x192 = 23k TDC channels • 1024 bins/channel at 2byte precision • Offline Database: 46Mbyte RMS 3.993 RMS 0.7789 σ = 0.7659 ≈ 18ps no INL applied INL applied Hanghzou Workshop on STAR TOF

  7. Outline • TOF Timing • HPTDC chip • Calibration for HPTDC Non-Linearity • TOF Performance Monitoring • Online Monitoring • Prompt Analyses • TOF Offline Analysis • Fast Offline QA • Overall Layout • Matching Algorithm • Physics Production Chain and Calibration • TOF Offline resources/organization • Summary & Outlook Hanghzou Workshop on STAR TOF

  8. TOF Online Monitoring Embedded in the STAR Online Monitoring code • Provides a fast check of the TOF system status • occupancy/Dead channels • correlation of East/West upVPD hits • time information of TOF hits • etc. etc. • Widely used during Run 8/9 • 7 pages, 20 histograms • new version will soon be deployed • includes data-integrity checks Hanghzou Workshop on STAR TOF

  9. TOF Prompt Analyses • Data integrity/consistency • verify TOF consistency of TOF data headers • see http://www.rhip.utexas.edu/~lli/tof/ • part of this can be moved to Online Monitoring • Dedicated noise runs • dedicated TOF “pedestal” run (pedAsPhys_tof) • count #triggers in 5μs trigger-matching window at a ~3.5kHz STAR trigger rate • prompt analysis of Leading and Trailing Edge noise rates for each MRPC channel • see http://www.rhip.utexas.edu/~tofp/var/rts/ Run #10105009 Tray-19 Leading Edge noise Hanghzou Workshop on STAR TOF

  10. Outline • TOF Timing • HPTDC chip • Calibration for HPTDC Non-Linearity • TOF Performance Monitoring • Online Monitoring • Prompt Analyses • TOF Offline Analysis • Fast Offline QA • Overall Layout • Matching Algorithm • Physics Production Chain and Calibration • TOF Offline resources/organization • Summary & Outlook Hanghzou Workshop on STAR TOF

  11. Offline DAQ Reader • New offline DAQ reader based on RTSReader • TOF data format specs v2.4★ • implemented Run 8 DAQ TOF Branch StBTofHitMaker • fiber data status and trigger time are stored in StBTofHeader • leading-edge and trailing-edge values are stored in StBTofRawHit • INL-corrected LE and TE values stored in StBTofHit • StBTofCollection: • StBTofHeader • StBTofRawHit • StBTofHit ★) http://www.star.bnl.gov/public/tof/electronics/TOF_Fiber_Data_Format_v2_4.pdf Hanghzou Workshop on STAR TOF

  12. Fast Offline QA Offline DAQ • event-wise hit distributions • matched hit distributions • channel-by-channel timing distributions • requires fast-offline calibration by experts • Vz from upVPD, TOF PID • Implemented in StEventQAMaker • During Run 8 and Run 9 (500GeV) QA by TOF experts • MatchMaker will soon be included in Fast Offline Fast Offline Reconstruction EventQAMaker histograms QA by shift crew Hanghzou Workshop on STAR TOF

  13. STAR TOF Offline Analysis Layout geometry (btofgeo) GSTAR geant hits STAR/TOF DAQ DB Tables StBTofUtil StBTofPool TOF Offline DAQ reader StBTofHitMaker TOF Simulation Maker TOF Mixer Maker StBTofCollection StEvent StMcEvent StBTofRawHit StBtofHeader association StBTofHit StMcTofHit StBTofMatchMaker StBTofCalibMaker MuDst TOF BTofRawHit BTofHit BTofHeader StTrack StMuBTofUtil StMuDstMaker StBTofPidTraits Hanghzou Workshop on STAR TOF

  14. TOF Geometry Defintions btofgeo.g and vpddgeo.g provide various TOF/VPD geometries: • btofgeo.g -- btofConfigure • vpddgeo.g -- vpddConfigure Hanghzou Workshop on STAR TOF

  15. TPC tracks & TOF matching Expect to see a similar plot for Run-9 500GeV soon. • p+p tof-tpx trigger data • ~120k from run #9056082 • ~45k good matched TPX tracks with TOF hits Hanghzou Workshop on STAR TOF

  16. Matching Algorithm StBTofCollection StEvent Track Nodes (global) StBTofHit StBTofPidTraits Track projection on TOF Fired TOF Hits Projected TOF Hits Matching of hits within one pad distance • TOF Cell Index • Timing • Projected position • Associated Track Init Matched TOF Hits Associate one TOF hit with multiple tracks … and remove One track with multiple TOF hits Singly-Tracked Matched Hits Final Matched TOF Hits Hanghzou Workshop on STAR TOF

  17. Physics Production Chain StBTofHitMaker StBTofMatchMaker DB Tables StBTofUtil StBTofCalibMaker STBTofNtupleMaker StMuDstMaker/StMuBTOFUtil Trees for Calibration Hanghzou Workshop on STAR TOF

  18. Database Tables • Active Tables (i.e. relevant to BTOF) Hanghzou Workshop on STAR TOF

  19. From StEvent to MuDst • MuDST more compact than StEvent • allows essential StEvent objects to be rebuild in memory • TOF branches in MuDst are filled by StMuDstMaker::fillBTof • TOF branches in MuDst • structure StMuBTofHit • modified from StBTofHit using StMuBTofUtil::fillMuBTofHit • structures StBtofRawHit, SBtTofHeader • direct copy from StBTofCollection • TOF PID traits in StMuTrack • StMuTrack::muBTofPidTraits • Structure: StMuBTofPidTraits: modified from StBTofPidTraits Hanghzou Workshop on STAR TOF

  20. Calibration Summary Run 9 (500GeV p+p): Fast-offline based production of 3.7M events finished Hanghzou Workshop on STAR TOF

  21. Outline • TOF Timing • HPTDC chip • Calibration for HPTDC Non-Linearity • TOF Performance Monitoring • Online Monitoring • Prompt Analyses • TOF Offline Analysis • Fast Offline QA • Overall Layout • Matching Algorithm • Physics Production Chain and Calibration • TOF Offline resources/organization • Summary & Outlook Hanghzou Workshop on STAR TOF

  22. Offline Software: people • Online Plot: J.Liu • Offline QA: L.Li, M.Wada, X.Zhang, Y.Zhou • Calibration: Z.Tang, X.Zhang, J.Liu, X.Zhu, M.Shao L.Ruan • Chain Makers: X.Dong, F.Geurts • Geometry: W.Llope, X.Dong • Simulation: D.Thein, L.Ruan, F.Geurts • Database: X.Dong, F.Geurts • VPD: X.Zhang, J.Zhou, X.Zhu, Y.Xu • PID: C.Markert, M.Wada, L.Li • Coordinator: F.Geurts • many thanks to X.Dong! • Institutes: BNL, LBNL, Rice, Tsinghua, USTC, UT Austin Hanghzou Workshop on STAR TOF

  23. Offline Software • weekly meetings • Wednesday 1h30pm EST • switch to EVO-based • widely in use in high-energy community • STAR community exists, too • get an account (www.caltech.edu/evo) • topical meetings • as needed • early connection with PWGs • include TOF-based PID • efficiency (embedding) Hanghzou Workshop on STAR TOF

  24. Summary • TOF Offline Software is in a good shape • Online Monitoring and FastOffline QA well integrated in STAR framework • Migration to a new StEvent model is almost completed • STAR offline software review (Nov.’08) provided useful feedback ahead of Run 9 • Decouple prototype software support and maintenance • Matching and Calibration procedures/software have been tested for several years using the TOF prototypes • Database tables are well maintained for offline analysis • Run-9: Efficiently handle the significant increase of channels that comes with a Large Area TOF • jump from 4 to 75% of the full TOF • optimized various aspects of the offline framework • database loading! Hanghzou Workshop on STAR TOF

  25. Outlook • Continue Particle Identification method development - integrated with dE/dx • Simulator development • Efficiency • Embedding and association • Include “start-less” TOF analysis • relevant in low-energy runs where upVPD may not be very efficient • Connect early with STAR PWGs and have TOF PID included in many physics analyses Hanghzou Workshop on STAR TOF

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