Tuesday, Jul 2, 2013 11:00am EDT

Agenda

• Formulate Near term (MIE) & long-term plans
• theta reconstruction -- first pass at formalism:
  • http://ace.phys.virginia.edu/MollerSpectrometer/130702_003412/plots_theta.pdf

Minutes

• Participants:
  • Seamus, David A., Mark Pitt., Rupesh, Wouter,

• Theta resolution -- determine kinematics?
• How well from these distributions is the spec giving us the same theta as

• Seamus:
  • What do we need for the GEMS?
    • - spectrometer limiting factor.
  • How do we determine the spacing of the GEMS?

• David A.:
  • Thin target at exit window location to do much of the calibration.

• Seamus:
  • Putting something with high Atomic mass for target will be useful
  • Do not have a generator yet..

• David A:
  • Want a theta resolution plot: disentangle r/dr/phi/dphi dependence

• Seamus
  • Based on theta resolution, we will want to justify our GEM resolution

• David A.
  • With LH2 target, do not have z info. So need thin target to get tight correlations.

• Seamus
  • Poor optics upstream of target, but more rates from upstream too -- something to keep in mind

• David A:
  • Need thin targets upstream/center/downstream location of the LH2 target.

• Seamus:
  • Wrap this analysis for MIE.
  • Adjust the collimator (roughly as well as we could survey them)

• Dave A./Mark P.:
  • How does the APV change with collimator?

• Seamus:
  • Variable that we would want to change -- add the various

• David A.:
  • radial motion would be the dominant one
  • take one collimator aperture, and move it radially by some amount -- 150 microns (survey) -- several mm.

• Mark P.:
  • Look at Dave Mack's slide: tolerance in z and r.

David A.:

• • Variables to look at:
    • Moller APV
    • distribution of theta, y

• Seamus:
  • Inner/Outer collimator motion
  • B-field: Going to be some variations in the field -- vary the field by 1%, get dA/A: twist in phi, r. Ideally would want new field maps, but tweaking the field that we have will give us some idea as well.

• David A.:
  • Move magnet, detectors

• Seamus:
  • Beam & target should stay fixed
  • Need raster ON for these.

• David A.:
  • Ignore moving in z for anything: out sensitivity would be much less in z compared to r

• David A.:
  • What are we comparing our Moller APV to?
  • Moving dets would shift the Moller distributions, and change APV in any detector.
  • Which is the APV that we would want to compare against? Mollers, averaged over all sectors?
    • Averaging over all sectors would make us insensitive to motion in phi.
    • Same with magnetic field?

• Seamus:
  • B-field couples with the collimator -> therefore phi changes in B-field would affect APV.

• David A.:
  • Radial tails have lower APV, and will lose these first when moving dets.

• Meet in a week, same time.