Compton Meeting, May 14, 2013 (L210A)

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Agenda

Usual meeting room (L210A).

Miscellaneous

• Nothing.

Laser

• Schedule for laser table work (Mark and Dave).

Photon Detector

• Look at backgrounds via scalers - correlate with extracted asymmetries.
  • Not yet, plan to do it along with a replay to save time (jc2).
• Follow up from last week:
  • Few events that deposited more energy than the incident photon [1] --> any conclusions?
  • Checks using "default" GEANT routine for summing energy?

Electron detector

• Studies including clustering trigger --> and efficiencies?
• Efficiencies from tracking mode data (accounting for angle of electrons on detector)

Minutes

• No objections to maintaining same meeting time over the summer.
• Laser work in tunnel needs to be wrapped up in the next couple months. Would like to remove as much laser equipment as possible before demolition begins in the fall.
  • In addition to verifying no loss of polarization in transit to cavity what else to be done? MD and DG to consult with Kent.
• Photon detector: N/A
• Electron detector:
  • Elog 526 - just showing impact of different trigger cuts on energy distribution
  • Elogs 527 and 528: even with "strict" trigger, variation of polarization from plane-to-plane is on the order of 0.07%. In this context, the polarization variation of 0.15% with changing vertical edet position (0.15% for 0.2 mm) seems like no big deal.
    • EDIT: Thinking on it again - this IS a big deal. It's almost certain that we did not position the detector at the same spot with 1 strip reproducibility during the experiment.
    • Dave suggests looking at consistency between MC and analysis, i.e., there are still some "imprecise" values for c floating around. Is assumed geometry in analysis consistent with geometry used in MC?
  • VT is working on detector efficiency from tracks - accounting for the fact that electrons are not at normal incidence to detector. Nothing worth showing yet - but making progress.