Compton Meeting, October 3, 2012 (F228)

1. Dial Toll-Free Number: 866-740-1260 (U.S. & Canada)
2. International participants dial:
Toll Number: 303-248-0285=
Or International Toll-Free Number: http://www.readytalk.com/intl
3. Enter your 7-digit access code, followed by “#”

 --> our access code is 3227471

Agenda

Meeting room, F228

Miscellaneous

• Pass 2 analysis
  • BPM offsets ELOG 243 understood?
  • Low current BCM calibration done Moller Elog 110
  • Remaining analysis tasks Tasks

Laser

• Direct test of cavity polarization maximization method: Laser elog 201 (Mark is back, maybe he cares to comment)

Electron Detector

• Further discussion of analysis technique, 2 vs. 3 parameter fits Edet log 431
• Further noise-related discussions
  • One suggested test from 2 weeks ago was to analyze Moller-Compton-Moller data with and without noise subtraction (Is this test done yet?)

Photon Detector

• Tasks
  • Analytic calculation of analyzing power with continuous fit to non-linearity
  • Lead-tungstate in MC

Notes/Minutes

Present: Dave Gaskell, Amrendra Narayan, Wouter Deconinck, Mark Dalton, Juan Carlos Cornejo (notes), Vladas Tvaskis, Dipungkar Dutta

• BPMs
  • Will use relative gains found from BPM measurement. Introduce to code as alpha= BPM+ / BPM-
• BCMs
  • Dave: Calibrated low current running
  • JC2: Will enter all BCM calibrations into the analyzer
• Laser
  • Mark: Nothing new to add. We need to determine priority for moving forward. He suggests at the moment laser work has low priority when compared to Qweak.
  • Deffer polarization work until later...
• Electron Detector
  • Vladas: Shows 3-parameter fit ELOG
  • Discussion of goal:
    • Dave: Goal was to do 3-parameter fit only
    • Vladas: Goal was to also be able to distinguish systematic errors from statistical errors.
    • Dave: Complicating things. If 3-parameter fit works, why not just use it?
    • Mark: The non-systematic error is not statistical error. It is fitting error. We can't avoid including it.
    • ...
    • Dave: Extra work is circular, if we already do the 3-parameter fit and it works, why then go back to 2-parameter fit? Instead, do the 3-p fit and then go do 3-p MC and see what systematics we get.
    • DD: The issue is to do the same N-parameter fit in MC as in data. Which to use? That is the question.
  • Noise correction for Moller-Compton-Moller
    • Has not been done yet.
    • Amrendra: Prefers this to be done soon-ish, because he wants to compare to his method that does laser cycle analysis which removes the noise.
• Photon Detector
  • Linearity issues
    • JC2: Will make a piecewice fit to the linearity data.

Action Items

• (**JC2**): Make ELOG about BPM calibration. Feed values to analyzer.
• (**JC2**): Enter BCM calibrations into analyzer
• (**Vladas**): Change the 3-fit to set the max parameter fit (the CE) as the higher-side-edge of the strip, instead of the lower side. Then see how things change.
• (**Vladas**): Will do the Moller-Compton-Moller analysis without taking the noise into account.
• (**JC2 && Wouter**): Will look at analyzer crash.