JEF meeting, April 4, 2025

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Connection

Meeting time and location:

Agenda

Detector checkout Sasha, Hakob, Vlad

    • Tuning timing delays for the ECAL alpha-source trigger [1]
    • Testing ECAL magnetic shielding
      • List of LED runs taken during the magnet ramp-up [2]
    • List of runs
    • LMS amplitudes

Restoring PS test setup [3]

  • Fabricating prototype consisting of 5x5 PWO4 and 5x5 LG modules (PS test setup)
    • ECAL modules exist, have been testes using an LED
    • LG modules will be instrumented with the resistive dividers (borrowed from Hall D)
      • all dividers were testes
      • modified PMT coupling to the LG block, use G10 tensioning plate to push the PMT towards the module
      • testing LG PMTs (FEU-84)
    • The prototype will be places inside the CCAL box
      • modified the cooling plate to accommodate all modules

Monitoring

Calibrations

Minutes

Attendees: Yuyao, Sasha, Hakob, Vlad, Igal, Bill, Zisis, Mac, Drew, S.T.

  • Final detector checkout completed
    • Timing delays of reference PMTs relative to LEDs set
    • No new issues with dividers found
  • While solenoid was ramping up, studied how well ECAL magnetic shielding was working by looking at changes in amplitude using LMS data
    • Found maximum relative difference between full field at 1350 amp and low field (not quite at 0 amps) ~3%
      • Deviations not symmetric about the beam pipe -- most differences seen in south top quadrant of ECAL
        • GEMTRD prototype is below south bottom quadrant
        • Impact of DIRC boxes?
    • Looked at deviations as a function of field for several channels
  • Setup of 5x5 PWO + 5x5 LG prototype to be installed on PS arm in hall continues
    • Need table rated for weight of COMCAL box plus crystals and blocks
    • Need 2 more flash-ADCs
    • Base of COMCAL box extended to accommodate all LG blocks
    • Using resistive bases for LG borrowed from Hall A
      • Good signal quality but large spread in amplitudes
      • Dividers use connector that needs to be converted to SHV, patch panel needed
    • Hakob checkout out all LG modules using dark box
    • Tensioning plates to push LG PMTs toward cookies being added
    • Added block to align lead tungstate crystals with LG blocks
    • Ready to start assembly
    • PS arm occupied for first ~1.5 months
  • S.T. on FCAL/ECAL shower reorganization
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