JEF meeting, January 13, 2022

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
  • Received all 150 CRYTUR crystals from physics division (22-C0275) [1]
    • Expect to receive 95 more CRYTUR crystals in May (835 + 95 = 930 in total)
  • Wrapped CRYTUR crystals: 835 (ALL available CRYTUR)
    • 10 crystals wrapped since last meeting
    • Available for wrapping: 10 CRYTUR crystals, 140 SICCAS crystals from CCAL
    • Mindy (DSG group) continues wrapping crystals and soldering wires to sockets
  • Disassembling CCAL
    • CCAL moved to the ESB
    • All modules (with SICCAS crystals) are removed
  • List of available parts
• Module fabrication -- Sasha
  • Fabricated modules: Total 1408 (12 modules fabricated since last week)
    • All SICCAS 576 SICCAS
    • 832 CRYTUR, available: 3
    • Moving modules to the new lab (EEL108)
• Testing of PMT dividers -- Sasha / Arshak
  • All parts for dividers have been ordered
  • Install 25 modules with new dividers on the CCAL, build prototype of LV patch pannel (check rate and noise)
• Installation of the FCAL2 detector -- Sasha / Arshak
  • Detector installation page
  • Updates from the meetings with Tim's group [2]
  • Manpower and division of tasks
  • Projects for summer students
  • Meeting with the detector imaging group
• Light Monitoring System -- Arshak
  • Beam test
• Simulations/Analysis

Minutes

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

• We have received all 835 Crytur crystals we expected to receive last year
  • All wrapped
  • 95 more expected in May
• Grand total number of fabricated modules = 1408 (only 3 more crystals available for fabrication in lab)
• COMCAL removed from hall
  • Modules need to be at least partially disassembled
    • Replace 25 micron brass straps with 50 micron brass straps? re-wrap?
    • Some tedlar had grease contamination due use of grease for optical coupling
    • PMT shielding: replace FR4 with soft iron
    • Need to remove plastic cap holding optical fiber
• Plan to install 5x5 prototype using COMCAL crystals in hall
  • Instrument with new electronics to test hight rate response
  • Check 3x amplifier in new PMT base design
    • Have 25 bases in house
    • Test noise level
• Plans for module installation coming together: student help, procedures, shims and alignment tools, ...
  • Expect some help from imaging group
• Arshak continuing to work on LMS beam test using 3x3 matrix
  • Plexiglas plate in front with similar design to actual plate but smaller size
  • Middle fully instrumented with FCAL-2 module, sides blanks with varying light access in the front (close/open faces)
  • Measured cross talk using PS setup selecting particular PS tiles
  • Cross talk level <~0.5% integrating over all amplitude, but most of the amplitude is near pedestal
    • Suggest look at amplitude dependence
    • MC simulation of effect?
• Also discussed using individual fibers for LMS
  • Not enough light from 250 micron fibers? Thicker diameter fibers more difficult to bend
  • Light uniformity?