JEF meeting, March 31, 2023

Meeting time and location:

• 9:30 am EST (JLab time) remote only
• Zoom meeting ID: 161 050 9142 Passcode: 004965

Agenda

• Preparation of parts for FCAL2 modules -- Sasha
  • Available crystals:

    1450 (modules)

    32 (ready for fabrication)

    40 (installed on CCAL)

    (some CCAL crystals from the inner part will not be used for the FCAL2)

    95 expect to receive from CRYTUR in May [1] Expect to start shipping crystals in the 2nd week of April.

    Total 1617

  • Disassemble the CCAL prototype

30 good modules [2]

Modules installed in the inner part of the CCAL

• • George (DSG group) is unwrapping CCAL modules and removing LMS caps. He'll also work on preshaping ESR reflectors (100 pcs) for CRYTUR.
  • Mindy (DSG group) solder wires to sockets (while waiting for crystals). She will continue with crystal wrapping during next week.
• Module fabrication -- Sasha
  • Fabricated modules: Total 1482

    Currently available for fabrication: 0 (modules will be available during next week)

• Testing of PMT dividers -- Sasha / Arshak
  • FCAL2 modules with dividers installed on the CCAL [3]
• Installation of the FCAL2 detector & integration to GlueX -- Sasha / Arshak
  • Detector installation page
  • Updates from the meetings with Tim's group [4]

- meeting last week (follow up on the cable distribution and design of the LMS) [5]

• • Manpower and division of tasks
  • Projects for summer students
  • Summer Students (2023)
  • Disassembling FCAL
• Light Monitoring System -- Arshak
  • Update on LMS
• Simulations/Analysis

Minutes

Attendees: Igor, Sasha, Bill, Arshak, Eugene, Igal, Zisis, Jon, Susan, Olga, Jane, Malte, S.T.

• Crytur crystals expected to start shipping second week of April
  • George from detector support group working on ESR reflectors for this final batch of crystals
• COMCAL has been disassembled, 30 good crystals now in EEL126 to be converted into FCAL2 modules
  • Modules need to be unwrapped and LMS caps removed
  • Not planning to use inner modules of COMCAL due to potential radiation damage, but could be converted to spare modules (10-15)
• Total number of FCAL2 modules remains at 1482
• Got new PMT divider with new connector, gains to be compared to COMCAL dividers with bypassed amplifier
• All parts available for full set of dividers except for some resistors
• Sasha met with Tim regarding cabling
  • Design makes sure that there is no material in front of chains in FCAL dark room
  • LV/HV bundling/labeling good task for students?
• Decided to go with the individual fiber design for the LMS
  • Some discussion about Arshak's design to punch holes in Rohacel foam (need not be 12 cm thick as in prior design)
  • Some discussion about bundling of fibers and location of integrating sphere (most likely outside dark box)
  • Arshak working on test setups for ~50 fibers at a time: scanner of fiber light output to be installed in ESB?
    • Developing automated procedure to choose good fibers
• Sasha showed that the inner FCAL blocks show obvious radiation damage
  • Also found evidence that some of the LG blocks have cracks. Most of these are in the periphery, maybe by design during the initial construction?
    • Could possibly be checked using small laser
  • FCAL will be surveyed this week -- need to measure stack heights
    • Also need to match bar codes on LG blocks to physical location --> database
• U.Regina group working on machine learning to identify splits from charged particles in FCAL-2 using I.U. approach
  • Trained on omega events, test on eta events?