October 19, 2022 FCAL Insert Installation Meeting

Meeting Time and Place

Wednesday October 19, 2022 10am At Jefferson Lab, Hall D Counting House and on Teams

Agenda

• Minutes from last meeting https://halldweb.jlab.org/wiki/index.php/October_05,_2022_FCAL_Insert_Installation_Meeting
• Discuss Lead Glass and crystal module removal/install [1] - Sasha
• Discuss cable mapping - Sasha
  • Existing cables
  • New Cables
• Cable quotes Chris S.
• Patch Panel requirements
• Initial testing of modules before removal - Mark D.
• Revisited removal of darkroom -
  • All cables need to be removed from darkroom to be able to install new detector
  • may be able to only partially remove Framing
  • Maybe able to crane frame off platform partially assemble
  • Rework for patch panels
• Updated Schedule
• Monitoring system discussion
• Assembly in ESB
• Media:FCAL2_strawman_schedule.pdf

Minutes

• Reviewed minutes from previous meeting
• Sasha showed wiki page he started for FCAL2 installation
  • gave 7 possible categories of condition of existing glass modules
  • Lead glass modules have aluminum towards glass
  • Crystals have mylar towards crystal
  • Sasha estimates 40 minutes to rewrap a module with proper training
  • Need to determin qty or al mylar, silicone sheet and what else needs to be procured
  • Suggested students can do wrapping
  • Showed HV and current for each existing module
  • maybe 2 people from Cuevas to help with unstacking and stacking
  • Tech group will have availability during this time
  • Detector support group may have folks available to help
• Sasha needs more time for cable mapping - will make separate meeting
• Mark Dalton presented status of existing modules in 4 categories
  • 187 original bases saturated
  • 206 new bases saturated
  • 1018 new bases < 1790V
  • 1309 original bases < 1790V
• Possibility to mark prior to removal
• Maybe perform stress test on existing modules to see condition prior to removal
• Maybe remove bad bases before unstacking - need to plug end so pmt does not fall out
• Have about 50 good spare pmts besides 400 that will not be used
• discussed pre-sorting as removing from stack vs. just toss them in a bin for sort later
• Need to work out sorting procedure to determine required shelving
• do we also wish to inspect from US side prior to unstacking to label cracked or brown ones?
• Chris S. ordered 1600 RG174 signal cables and connectors - 20 weeks - $83K
• Have all external HV cables on connectors - they still need to be attached
• Lengths are needed for all HV and LV cables inside dark room
• LV cables are ribbon cables inside dark room
  • No daisy chaining
  • Can we reduce to 3 wire instead of 10 to save space?
• Monitoring Panel
  • fibers have about a 1" bending radius with 10% loss in signal
  • Leave clearance on side edges of Rohacell to allow fibers to come out and bend around US surface of outer monitoring panel
  • Outer plexiglass and rohacell can be held together using plastic push pins
  • Need to get details from Matt S. for outer LED attachments
  • discussed need for gasket on from brass face of each crystal to reduce possibility of cross talk
  • Sasha discussed changing to individual fibers for each crystal
    • is this needed for calibration?
    • what is the requirement for the monitoring system?
    • continue with the current design
    • Final decision needed by December
    • Arshak doing more studies
• Cable trays to be determined once cable configuration is defined