Difference between revisions of "September 25, 2019 FCAL Insert Design Meeting"

Revision as of 09:09, 25 September 2019

Meeting Time and Place

Wednesday Sept 25 1:30 pm At Jefferson Lab, room TED 2504

• Present - Sasha Somov, Josh Crafts, Vlad, Eugene, Stephanie, Keith Harding, Tim

Agenda

• Discuss Center tube
  • 1mm thick wall minimum. ID is 1.8 cm
  • Upstream end flush with upstream face of acrylic
• Discuss Tungsten absorber
  • Cover 1.5 crystals ok?
  • Rohacell supported
• Monitoring System
  • Use 1/2" Acrylic sheet with 45 degree angles on edges
  • How to attach fibers? Media:Acrylic_sheet.pdf
  • What size fibers?
  • Ok to make test piece as shown?
• 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
• 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 the center support tube
  • Need to determine material for center tube - Sasha
    • consider magnetic properties, thermal conductivity, strength, stiffness
  • Need to determine the maximum hole size allowable (assume steel initially) - Tim
  • Need to move the upstream end flush with US side of acrylic sheet - Keith
  • Need to decide on size of hole (2x2 crystals now) - Sasha
• Discussed Monitoring system
  • Use 1/2" acrylic sheet same as FCAL
  • Discussed possibility of pre-assembling the acrylic, fibers and rohacell
  • Determine diameter of fibers - Sasha
  • Layout fibers coming through rohacell and cut angles on acrylic - Keith/Tim
  • Add fibers to inner hole edge
  • Fabricate a test piece - Tim/Keith/Josh
• Discussed feedthru panels attached to cable support chains
  • Cables are stiff, ok to attach panels to cables with hinge
  • Use ComCal feedthu sizing to develop panels - Keith
  • Cables should be strain relived to chains
• Discussed cooling system
  • Concept to glue copper tubes to aluminum blocks with thermally conductive epoxy accepted
  • Concept to clamp cooling plates to inner support tube accepted
  • Assuming 2.1KW total heat load, we would need 2 of the chillers used for BCAL.
  • Continue with connections and manifold layou - Keith/Tim
• Discussed Brazing of PMT module straps and new mag field tests
  • Josh has successfully brazed and cleaned (warm water) an assembly and is testing
  • Test with 2mm cookie to ensure enough pressure can be maintained for good transmission - Josh
  • Sasha wishes to assemble a new 9 module array for magnetic field testing
    • 18mm diameter light guides are needed - Tim
    • 6mm longer with 50 micron larger ID mag shield steel needed - Tim
    • additional mu metal shields needed (same as previous - 350 microns) - Tim
    • Have steel shields annealed - Tim
• Discussed test fixutre for PMTs in beam
  • Need to fabricate steel case - Tim
  • need to fabricate support structure - Tim
  • Need to fabricate feedthru panel - Josh/Tim
  • need to fabricated aluminum base plate - Josh/Tim

Action items