NPS Frame and Infrastructure Meeting (JLab, 1/31/2019)

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Revision as of 12:46, 4 February 2019 by Brads (talk | contribs) (Added action item on temp logging; requested that carbon fiber sample be sent to Brad S)
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Frame mechanical design


  • PMT assembly
  • as long as use non-magnetic material for the cylindrical tubes holding divider should be ok
  • suggestion to use a standoff screw - would move access further to the back for easier access
  • Cables, PCB, connectors
  • need to check if can also increase vertical size - might hit SHMS water lines
  • piece still needed to finalize for cable routing: NPS to front of SHMS
  • discussion about grounding - might want to check with prototype and optical path disconnected - still see signal?
  • cable making responsibility
  • need to identify responsibilities for module assembly
  • Thermal aspects
  • find out dew point in experimental hall (need to make sure water will not condense/drip on components and heat exchanger inside NPS frame)
  • Radiation hardness carbon fiber
  • place sample in hall (give it to Brad S)
  • Slow Controls / Logging for temperatures


  • PCB Interface (HV, anode current, LED; 25cm(W) x 80cm(H))- updated design to improve access to PMTs
  • Calorimeter design still same - plan to work on in Feb/March
  • Reflector test for cross talk (Ho San) - result suggests negligible, no tedlar needed
  • Calorimeter support - design to be finalized and check with mock-up, plan to work on Feb-April
  • New PMT assembly design
  • Only need to unscrew in one place now
  • Captive screws - cannot fall during (de)installation
  • Long cylinder tubes hold divider assembly
  • Cables, PCB, and connectors
  • PCB has been successfully constructed and tested - ready for construction
  • Signal: sma
  • HV: Fisher
  • LED command connector: Samtec
  • Increased box size to have more room for pushing cables left/right - gives more slack for cables, top of box LED connection is fixed
  • review of cable routing plans from (11/13-11/15/2018)
  • Signal: special patch panel to go from LEMO to BNC - RJ178 seems preferred as less bulky
  • HV: multi-channel
  • all cable connectors are on top of the detector box - LEMO as fits better
  • discussion about making cables and cost
  • 20 euro/cable (parts and labor), rate=4 cables/hour (need 250 hours labor)
  • drawings and instructions prepared by IPNO
  • discussion about module assembly
  • many parts of the process (c)should be done by collaboration, some things like pre-shaping of the reflector might be better to do external
  • Thermal aspects
  • Crystal + external zone (intermediate and heating zones, 500mW/channel -> 540 W)
  • Most important is the temperature stability
  • Heating zone cooled by two heat exchangers, fans, and one chiller - effectively over-dimension (create a temperature bath) since have no idea about the air flow in that region, many cables
  • discussion about temperature monitoring
  • planned for front and back of crystals, no space in-between
  • discussion about condensation
  • if/if not need a dryer depends on temperature that run bottom heat exchanger to get 3kW, humidity in hall usually not that high
  • if need a dryer could use a system like Hall A's
  • Radiation hardness test of carbon fiber material in hall - preferably during high current running