October 9, 2019 FCAL Insert Design Meeting

Meeting Time and Place =

Wednesday Oct, 9 2:00 pm At Jefferson Lab, room TED 2504

• Present - Sasha Somov, Josh Crafts, Eugene, Stephanie, Keith Harding, Tim, Fernando, Chris Stanislav

Agenda

• Action items from last meeting https://halldweb.jlab.org/wiki/index.php/September_25,_2019_FCAL_Insert_Design_Meeting
• Discuss Tungsten absorber
  • Cover 1.5 crystals ok?
  • Rohacell supported
• Monitoring System
  • Use 1/2" Acrylic sheet with 45 degree angles on edges
  • Testing plan
  • 1mm fibers
  • 15cm square with 6mm 45 degree bevel
• Cooling of blocks - 2.1 KW needed
  • 2 Chillers like those used for BCAL ($16K ea)
  • 4 water to air Heat exchangers around crystal area
  • 9 parallel circuits for each chiller
  • potted copper tube into aluminum blocks
  • Cooling of inner tube - removable plate
  • Proposed manifold similar to BCAL - needs to clear for FCAL module removal
• Support structure and assy sequence
• electronics patch panels DS of crystal pmts
• Discussed Brazing of PMT module straps and new mag field tests
  • Sasha wishes to assemble a new 9 module array for magnetic field testing
    • 18mm diameter light guides are needed - josh found some on Amazon - tim will order
    • 6mm longer with 50 micron larger ID mag shield steel needed - Submitted to machine shop Media:1020_shield.pdf
    • additional mu metal shields needed (same as previous - 350 microns) - Tim ordered Due Oct 18-
    • Have steel shields annealed - Tim looking into it >900C
• Discuss test fixture for PMTs in beam
  • Need to fabricate steel case - Media:Steel_shield.pdf
  • need to fabricate support structure - Tim
  • Need to fabricate feedthru panel - Josh/Tim
  • need to fabricated aluminum base plate - Josh/Tim

Minutes and Action Items

• Discussed Tungsten absorber
  • No decision on coverage, still at 1.5 crystals
• Monitoring System
  • Need to order diamond end mill - Tim
  • 1mm fibers for test
  • 2 Test samples made, 15cm square with 6mm 45 degree bevel
• Cooling of blocks - 2.1 KW needed
  • Inner cooling ring move to be in line with outer to keep area behind lead-glass module clear for repairs - Keith
• Support structure and assy sequence
  • Discussed sequence and shimming in detail
  • Need to develop a more detailed plan to show next meeting - Keith/Tim
  • Screen shots for Eugene - Keith
• electronics patch panels DS of crystal pmts
  • Some more discussion on panels - not much more detail given
  • Fernando needs geometry info for cable lengths - Keith
  • Need more info on connectors/patch panel - Fernando
• Discussed Additional testing for the final design
  • Josh continuing tests Brazing of PMT module straps
  • Sasha wishes to assemble a new 9 module array for magnetic field testing
    • 18mm diameter light guides are needed - josh found some on Amazon - tim will order
    • 6mm longer with 50 micron larger ID mag shield steel needed - Submitted to machine shop Media:1020_shield.pdf
    • additional mu metal shields needed (same as previous - 350 microns) - Tim ordered Due Oct 18-
    • Have steel shields annealed - Tim looking into it >900C
• Need fixture for testing crystals in hall (PS beam right)
  • 12 at a time
  • Josh assembling a fixture
  • Aluminum support clip fabrication - Stephanie
  • Josh to supply stp file for aluminum base plate - Stephanie to make dwg
  • Josh to supply stp file for copper soldering head - Stephanie to make dwg
  • Steel shielding cage - Tim sketched, need to check overall design - Stephanie/Tim
  • Need to make a stand - Tim