Difference between revisions of "Tuesday, Jul 2, 2013 11:00am EDT"

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== Agenda ==
 
== Agenda ==
  
−
* Near term (MIE) & long-term plan
+
* Formulate Near term (MIE) & long-term plans
−
* Determination of theta:
+
* theta reconstruction -- first pass at formalism:
−
** http://ace.phys.virginia.edu/MollerSpectrometer/130702_003412/plots_theta.pdf
+
** http://ace.phys.virginia.edu/MollerSpectrometer/256
 +
 
 +
== 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.
 +
 
 +
==Things to Do==
 +
* What is the required GEM resolution?
 +
** Plot reconstructed theta - Monte Carlo theta, and get the RMS of the distribution
 +
* Sensitivities to collimator, B-field and detector locations
 +
** Modify (inside/outside) collimator locations in r, B-field in r & phi, detector locations in r
 +
*** observe the affects in Moller APV (compared against septant averaged Moller APV)
 +
*** observe the variation in distributions of theta, y

Latest revision as of 14:50, 2 July 2013

Agenda

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.

Things to Do

  • What is the required GEM resolution?
    • Plot reconstructed theta - Monte Carlo theta, and get the RMS of the distribution
  • Sensitivities to collimator, B-field and detector locations
    • Modify (inside/outside) collimator locations in r, B-field in r & phi, detector locations in r
      • observe the affects in Moller APV (compared against septant averaged Moller APV)
      • observe the variation in distributions of theta, y
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