August 27, 2014 Calibration

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GlueX Calibration Meeting
Wednesday, August 27, 2014
11:00 am, EDT
JLab: CEBAF Center, F326

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Agenda

  1. Announcements
  2. Commissioning Planning
  3. Fall 2014 Commissioning Simulations
    • Status Update
      • Commissioning target geometry in branch hdds-commissioning

Commissioning target.png Commissioning target closeup.png

    • Number of Events & Final States
    • EM Background Simulations (Sean)
    • EM Background Simulations (Simon)
      • Mockup of Level 1 trigger:
        • Version A: (Ebcal + 4.0 Efcal)>=2.0 && Ebcal>0.200 && Efcal>0.030
        • Version B: (Ebcal + 4.0 Efcal)>=2.0 && Ebcal>0.030 && Efcal>0.030 && N(start counter hits)>0
        • Version C: Efcal>=0.250
        • Version D: Efcal>=0.250 && N(TOF hits)>0
      • Coherent bremsstrahlung generator: 10 GeV electron beam, 5 mm collimator, Emin=1.2 MeV.
   Events |                   Trigger               |           Events with segments
          |         A         B         C         D |          A         B         C         D

    97172 |       169        70        44        44 |        122        67        29        29 

Fraction: | 0.0017 0.0007 0.0005 0.0005 | 0.0013 0.0007 0.0003 0.0003


  1. Action Items
  2. AOT

Action Items

  • Update desired event counts (all)
  • Tag new sim-recon version (Mark I.)
  • Update geometry for commissioning running (Simon)
  • Obtain new constants for EM background simulation & magnetic field (Sean)
  • Update expected photoproduction event rate calculations
  • Decide number of events & conditions to simulate
  • Run simulations
  • What is the lowest solenoid current that we can run at? How will a low solenoid current affect FDC alignment?
  • Study FCAL & BCAL trigger thresholds

Minutes

Attending: Sean (CMU); Naomi, Curtis (CMU); Matt S., John Z. (IU); Simon, Lubomir, Beni, Mark I., Mark D., Eugene (JLab); Zisis, Tegan (Regina); Justin (MIT)

Announcements

Curtis mentioned that in the latest meetings with the accelerator group, it sounds like there will be the possibility of taking additional data on evenings and weekends in November and December, beyond the 3 weeks we have been planning for. Therefore, we should be planning to make as many calibrations as possible with the available data.

CDC

  • Naomi presented an updated commissioning plan, which had two main parts. In early running, old HV supplies would be attached to the inner straws to measure the currents induced by the photon beam. After that, a healthy sample of tracks taken with the magnetic field off are needed.
  • Beni suggested to look at what would happen if targets at different positions and with different thicknesses were used.
  • Simon has been running his alignment code with the currently collected cosmic data, which is giving generally reasonable results though there are some outliers. He plans to update his stimaes of how much data is needed. His current alignment plugin needs some small changes to work with straight tracks from the target instead of cosmics.
  • Generally, an estimate of how much raw mode data is needed would be useful.

FDC

See simulations below.

FCAL

  • The pi0 energy calibration code originally developed by Claire Tarbert is in several pieces. Matt is working with John Z. to collect this code and get it working in the DANA framework. This work has been delayed by several problems installing the GlueX offline software.
  • The plan is to start with pi0's being produced with the particle gun and work up to analyzing and balancing the gains using EVIO files.
  • An undergrad student is looking at omega photoproduction, with the decay omega -> gamma pi0.
  • The first pi0 data will be used to refine the PMT gain balancing. Further gain balancing can be done in software.
  • In principle, the first pass at timing calibrations can be done with data from the the LED monitoring system. This data is currently being analyzed.

BCAL

  • Zisis presented and reviewed the plans for BCAL calibration that were developed earlier this year. These plans are being updated based on the experience with cosmic data and simulations. The reconstruction software is being updated as well.
  • Mark D. reported that the current checks and calibrations are data limited - they plan to take as much cosmic data as they can before the beam.
  • Plans for pi0 and charged hadron energy calibration were developed a few years ago and need to be revisited.
  • Sean mentioned that it would be useful to know how the current calibrations will affect efficiencies during the fall running.
  • Beam data taken with and without magnetic field will be useful, the latter especially to determine the response of curving charged particles.
  • There have been problems installing the latest offline software at Regina as well.
  • Zisis requested 30% of the GlueX simulation needs on the Canadian Westgrid platform, and this request was well received.

TOF

  • Sasha O. is working on calibrations with the data currently in hand. Progress is being made though he is running into some trouble with events that have a lot of hits. Plans are to take more data.
  • They request to have some running with a thick target to determine the hit rates expected for the hydrogen target.

Start Counter

  • It is being constructed and hoped to show up at JLab next week. Fingers are being crossed.

Simulations

    • BCAL: DocDB documents 2361 and 2379 need updating together with Wiki info, and experience from this summer's cosmics and LED running, and MC simulations
    • TOF
    • Start Counter
    • Trigger
  1. Fall 2014 Commissioning Simulations
    • Status Update