Difference between revisions of "Tuesday, Jul 2, 2013 11:00am EDT"
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* Formulate Near term (MIE) & long-term plans | * Formulate Near term (MIE) & long-term plans | ||
* theta reconstruction -- first pass at formalism: | * theta reconstruction -- first pass at formalism: | ||
− | ** http://ace.phys.virginia.edu/MollerSpectrometer/ | + | ** http://ace.phys.virginia.edu/MollerSpectrometer/256 |
== Minutes == | == Minutes == | ||
* Participants: | * Participants: | ||
** Seamus, David A., Mark Pitt., Rupesh, Wouter, | ** 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
- Formulate Near term (MIE) & long-term plans
- theta reconstruction -- first pass at formalism:
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?
- What do we need for 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
- Variables to look at:
- 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
- Modify (inside/outside) collimator locations in r, B-field in r & phi, detector locations in r