November 02, 2022 FCAL Insert Installation Meeting
From GlueXWiki
Meeting Time and Place
Wednesday November 02, 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_19,_2022_FCAL_Insert_Installation_Meeting
- Discuss Lead Glass and crystal module removal/install [1] - Sasha
- 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
- Maybe able to crane frame off platform partially assemble
- Rework for patch panels
- Cable discussion fruitful
- Option D to move cables from inner 400 cables to adjacent crate
- Remove 2 crates and move to new racks
- Abandon 200 cables
- Patch panels worked out, 2 HV and 2 LV north and south side, 1 signal feedthrough plate downstream wall
- HV and LV cable length = 20 ft
- Signal cable length = 16 ft
- 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
Action Items
- Set up separate meeting for Cable mapping and requirements - Tim
- Continue to work on unstacking, categorizing and repair plan - Sasha, Mark D.?
- Develop layout for patch panels - Stephanie/Chris S
- Continue to develop current monitoring design - Stephanie/Arshak
- Work on cable tray layout - Tim/Stephanie
- Provide lengths for HV and LV cables inside dark room - Tim/Stephanie
