G2p Analysis Minutes
From Hall A Wiki
Minutes of the weekly analysis meetings
Contents
1/8/2014
Present: Kalyan, Chao, Jie, Min, Melissa
By Phone: Ellie, Toby, Ryan, Karl, Alexandre, Pengjia
Feature Presentations:
- Melissa:
- Gave a short update on yields for packing fraction runs. For one run (3864), the ungated livetime is significantly different then
the helicity-gated livetime. Using the average of the helicity gated LT values for the normalization makes this run agree better with
other packing fraction runs (3574 and 3727). She will check the beam position for these runs to see if this could have a large effect
on the yields. Her slides can be seen here.
- Gave a short update on yields for packing fraction runs. For one run (3864), the ungated livetime is significantly different then
- Chao
- Gave an update on the simulation package. Previously, the real theta and phi were not determined event by event, but for an entire
run. Since we know the position of the reaction point and the sieve hole, and the momentum of the electron, it is possible to use a
bisection method to determine the real theta and phi for each event. With this update it will be easier to determine the calibration for
different dp settings. Next he will work on finishing the optics calibration for the first setting with the target field. His slides can be
seen here.
- Gave an update on the simulation package. Previously, the real theta and phi were not determined event by event, but for an entire
- Min
- Gave an update on pointing analysis. The calculation was done using the March 14th calibration, using a carbon foil in liquid helium.
Using the carbon-12 ground state and first excited state to do the calibration of d(delta-E'), the results for the LHRS (4.40MeV) and
RHRS (4.42 MeV) agreed within the uncertainty with the nominal value (4.44MeV). However, including other uncertainties (survey and
beam x), add up to ~0.11 deg uncertainty in the scattering angle. She concluded that using the carbon foil in LHe is not ideal for a
pointing study. Next she will try CH2 run in longitudinal target field setting, once the optics calibration is complete for this setting. Her
slides can be seen here.
- Gave an update on pointing analysis. The calculation was done using the March 14th calibration, using a carbon foil in liquid helium.
- Pengjia
- Gave an update on the status of the BPM calibrations. He has finalized the calibrations for data taken from April 11th to May 18th,
which includes three different BPM gain settings. For settings before April 11th, the process is more complicated (larger pedestals,
auto-gain), but he will try to finalize the calibrations soon. He will provide a technote of his procedures and results. More details can
be seen here.
- Gave an update on the status of the BPM calibrations. He has finalized the calibrations for data taken from April 11th to May 18th,
General Discussion:
- If any students are interested in giving a talk at the APS April Meeting, please circulate an abstract to the group. The deadline for abstract submission is this Friday, January 10th.
