Difference between revisions of "Spring 2019 DIRC Commissioning"

From GlueXWiki
Jump to: navigation, search
(Commissioning Conditions)
(Commissioning Conditions)
Line 20: Line 20:
 
*Tagger quadrupole on (-4.2 A).  
 
*Tagger quadrupole on (-4.2 A).  
 
* Collimator hole: 5 mm diameter
 
* Collimator hole: 5 mm diameter
* Targets:
+
* Targets: [https://hdops.jlab.org/wiki/index.php/Cryogenic_Target_Shift LH2 cryogenic target]
**LH2 target: [https://hdops.jlab.org/wiki/index.php/Cryogenic_Target_Shift cryogenic target]
+
  
 
== Commissioning Goals ==
 
== Commissioning Goals ==

Revision as of 12:29, 21 December 2018

Commissioning Conditions

  • Beam energy expected 11.7 GeV
  • Solenoid on at 1350A
  • CW Beam current:
    • Range: 50 nA - 1.0 uA. 250 MHz frequency.
    • Chopper slit shared with Hall ???
    • Typical low-intensity commissioning expected to be 100 nA on JD70-105 (47 um diamond) or 225 nA on JD70-104 (17 μm diamond).
    • Some high-intensity running expected to test nominal 5 x 107 γ/s in coherent peak: 400 nA on JD70-105 or 900 nA on JD70-104.
  • FFB on or Position Slow Lock on (FFB doesn't operate below 50nA).
  • Radiators:
    • Goniometer radiators:
      • Diamond JD70-104 (17 μm - 1.4·10-4 R.L., 7×7 mm²) - wider rocking curve
      • Diamond JD70-105 (47 μm - 3.9·10-4 R.L., 7×7 mm²) - good rocking curve
    • 40 μm Al radiator (44.9·10-5 R.L.)
    • Amorphous
      • 1.64 µm Al (1.86·10-5 R.L., see study)
      • 10 µm Al (11.2·10-5 R.L.)
      • 30 µm Al (33.7·10-5 R.L.)
  • Tagger quadrupole on (-4.2 A).
  • Collimator hole: 5 mm diameter
  • Targets: LH2 cryogenic target

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