Tuesday, Jul 9, 2013 11:00am EDT

Logistic information

   Phone number:  1-866-740-1260
   Access code:   1978431#

Agenda

http://ace.phys.virginia.edu/MollerSpectrometer/259

Minutes

Attendance: Wouter, Seamus, Nilanga, David A., Rupesh, Mark P.

• Dave A.
  • 4 GEMs, provide wiggle room for inefficiencies and failures

• Nilanga:
  • ~95% efficiency - what we have measured so far
  • GEMs need to be out of vacuum
  • Need not worry about vacuum
  • With GEMs we can have resolution of about 100 um or so.
  • Can we improve th-th_rec by using 100 um instead of 500um

• David A./Seamus:
  • We need to be using r/dr as cuts, not th

• David A.

• Mark P.
  • The detector scans needed for Moller events, not ep

• David A.
  • Interested in Moller asymmetries
  • Collimator motions are important
  • Maybe eps will be sensitive to small angles

• Mark P.
  • Tolerances of positioning collimator hole
  • Does this change the distribution of millers, eps at the detector?

• Things to do:
  • Inner/out collimator motion
  • p6. plots with GEM resolution much worse
    • If 100um GEM res reduces the diff widths, then good,

else these widths are not determined by the tracking system.

• Seamus
  • 5m between the first and last GEMs -> Move the first/second GEMs closer to downstream GEMs

• David A.
  • Main purpose of good resolution is to verify that we have valid tracks
  • The distributions that we have are not going to change very much with resolution, I suspect