Photon Beam Polarimetry

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Revision as of 16:25, 13 February 2015 by Kmoriya (Talk | contribs) (Expected Timeline)

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This page contains a list of to do items for installing the triplet polarimeter for the Spring 2015 GlueX run. Items that used to be on this page are now at the bottom in Items From Before January 2015

Expected Timeline

  • February 2 - 5: Kei visits ASU (DONE)
  • mid-February: ship triplet to JLab (CURRENTLY WAITING)
  • First week after delivery: Survey by JLab
  • End of February - March 27: testing, installation
    • End of February - April 2: testing in EEL 126
    • April 3 - May 4: physics beam, installation when possible

Hardware Division

  • ASU
    • motor (data sheet)
    • controller
    • power supply
      1. 4 channels of +12V, 0.21 amps per channel
      2. 4 channels of -12V, 0.21 amps per channel
      3. 1 channel of +200V, the leakage current on the silicon strip detecter is 3.3 micro-amps
    • 32 short SSI cables with Lemo
    • vacuum rated limit switches (data sheet)
  • JLab
    • fADCs
      1. 2 fADC250s on PSC VXS crate
    • 32 coax cables with Lemos on both ends (Fernando). Require 55ft to racks
    • turbo vacuum pump (Tim)

Things to do at ASU

  • packaging, shipping
  • testing(?)

Things to do at JLab

  • preparation of hardware before shipment
  • installation
  • Monitoring
    • Would like to run the device below 50 mTorr to avoid voltage breakdown. Need pressure sensor, monitoring (Note: this is being extremely cautious. We will be running at ~200V, and even with 300V the required pressure is, given d = 1mm, <6Torr)
    • Humidity: no requirements
    • Temperature: would like to monitor temperature in collimator cave since we don't want the preamps to get too hot. Need temperature sensor, monitoring
  • testing with source(?) - will we test with source before installing in beam line?


  • write proposal, safety concerns/procedures
  • Beryllium use:
    • will be used as radiator foil, 25μm thick
  • Get approval from Bert
  • Pass by Patritzia

Analysis Procedures

  • beam requirements
  • requirements on other systems (PS, tagger)
  • analysis procedure
    • Think of procedure for high-level analysis to ensure data is good
  • online monitoring
    • fADC scalers for monitoring each sector → Hovanes
    • RootSpy plugin
  • MC - GEANT4 simulation available with previous geometry

Items From Before January 2015