Spring 2019 DIRC Commissioning

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Commissioning Goals

  • Integrate DIRC readout with general Hall D DAQ and online/offline monitoring
  • Confirm cabling through HV/mask checks with LED system
  • Calibrate per-pixel timing offset of MAPMTs using LED system
  • Determine geometric alignment parameters (position and angle offsets) for optical components
  • Implement reconstruction algorithm and compare data/MC: # detected photons, Cherenkov angle resolution

Commissioning Observables

  • "Ring" images for tracks with fixed kinematics (binned in position space over bars) overlaid on MC distributions
  • Per-pixel timing and Cherenkov angle differences (measured - LUT expected) to confirm geometry
  • Number of detected photons/track
  • Single photon resolution (SPR) per pixel

Commissioning Timeline, Tasks and Milestones

  • July 16-30: Integration of DIRC crate with DAQ and initial test of readout with standalone MAPMT module (Ben, Sergey, Sasha)
  • August-October
    • Implementation of DAQ decoder for SSP data format in sim-recon to create low level hit objects (David)
    • Calibration document with expected tables for CCDB (Oct 22) --- Justin
    • Implementation of Translation Table in CCDB to orient (FPGA, channel ID) mapping from readout into physical pixel coordinates (X, Y) position along readout window (Nov 1) --- David, Justin, Bill
    • Online and offline monitoring plugins to monitor occupancies and timing distributions (Nov 1) --- TBD
      • LED occupancy and timing calibration (Nov 1) --- Yunjie
      • Physics trigger occupancies and timing - possibly use TOF/FCAL as filter for tracks in different regions (Nov 1) --- TBD
      • Include DIRC hit patterns in event display --- TBD
  • October 29 - November 18 (3-week install period):
    • Verify cabling and translation table with LED data (1 week after install) --- TBD
      • Design unique patterns of HV and channel masks
      • Collect ~100k events in each configuration to verify mapping
    • HV and threshold scans with LED data (2 weeks after install) --- TBD
      • Duplicate scans of HV and thresholds as used in laser test setup (see below)
      • Determine initial HV and threshold settings for LED and beam data
    • Initial time offset calibrations with LED data (3 weeks after install) --- Yunjie
  • November 19 - December 19 (commissioning with beam):
    • Complete integration with DAQ under low-intensity beam conditions: (1 week)
      • Evaluate scaler rates and distributions relative to MC predictions
      • Mask any noisy channels for production data
      • Determine what global parameters can be optimized (beam current, bar box position, etc.) can be optimized
    • Production data taking with all sub-detectors in nominal condition (2 weeks, production overnight)
      • FCAL-BCAL production physics trigger with interleaved DIRC LED and random triggers
      • Collect sufficient statistics for optical alignment with identified ρ and φ, as well as more exclusive reactions with tagged Ks
    • Intensity scans (1 week, production overnight)
  • Evaluate rate dependence and backgrounds for both high and low luminosity
  • Scans of fixed amorphous radiator and varied current from 50 - 300 nA

Datasets to acquire with integrated DAQ

HV and threshold scans

  • Similar set of HV, MAROC gain, and threshold settings as laser setup for comparison with final implementation
  • Validate MAPMT characterization with both LED calibration and beam data