September 10, 2014 Calibration

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GlueX Calibration Meeting
Wednesday, September 10, 2014
11:00 am, EDT
JLab: CEBAF Center, F326

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  1. Announcements
  2. Collaboration Meeting
  3. Commissioning Planning updates
    1. CDC
    2. FDC
    3. FCAL
    4. BCAL
    5. TOF
    6. Start Counter
    7. Trigger
  4. Fall 2014 Commissioning Simulation updates
  5. AOB


  • Attendees: Curtis M., Naomi J, Eugene C., Mark I, Lubomir P., Simon T., Beni Z., Manuel L., Noemi O., Andrei S.
  • For the F125 Cody has implemented Mode 8 (raw + time + integral). Sparcification is now possible in all modes.
  • The FDC and CDC group have been taking cosmic data over the last few weeks. The plan is to use the CDC cosmic data to align the chambers. The FDC data has been taken with trigger scintillators used for studying the BCAL, so may be of limited use for alignment. Vladimir B. is starting to work on calibration of the FDC.
    • One curious thing is that the simulated rates in the FDC counters in Sean's recent simulation do not agree qualitatively with early background studies by Alex S. -- under investigation.
  • Calibration constants for other detector systems are being migrated to the CCDB. Noemi O. from Regina has started working on calibration for the BCAL.
  • The start counter has just recently been moved to the hall after initial checkout with a source -- no update on calibration.
  • Alex S. has been working on the trigger commissioning, but so far he is wrestling with hardware issues.
  • The geometry in the simulation for the commissioning run has been updated by Simon T. to include the beam line between the SEGblock shielding and the commissioning target. The model for the shield blocks and the pair spectrometer vacuum chambers has also been updated.
  • Curtis reported that he had tried to normalize the FDC rates from Sean's EM background studies to those that Sascha did in 2010. By normalizing the 1200A point in both, the rates from currents of about 200A up to 1500A all fell roughly on the same line. The following file plots the factor by which the EM rate increases against the decrease in current in the solenoid in 100A units. Thus, the point at x=0 and y=1 corresponds to 1500A current and a scale factor of 1.00. The point at x=13 and y=3.75 corresponds to a solenoid current of 200A and a scale factor of 3.75. The slope of the curve suggests that the EM rate increases by a factor of about 1.2 for each step down in solenoid current of 100A.
File:Solenoid Current.pdf
  • Mark I. announced a new version of CCDB that includes a fix to a multi-thread issue: CCDB_1.03