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03/25/2004
Cell development:
- Todd (W&M):
- made 4 1-inch-spheres, one 40cm regular geometry cell and one 40cm regular cell in the vacuum system all are hybrids
- Pumped the cell with 2 lasers but with different oven temperatures ==> polarization rate increases with oven temperature.
- Jaideep pointed out that it should be corrected for density.
- Jaideep (UVA):
- Working with temporary oven.
- Different tests are underway to finalize the design of the new oven: hope new oven to be ready in 3 weeks.
- Filled cells at 8 amagats.
Target lab:
- Lingyan:
- EPR wavetek is working fine.
- Ameya:
- Tested Nilanga's amplifier: it look to work fine.
- Did a spindown with field at 180deg and took NMR measurements 6 hours apart: uncorrected lifetime is 38.5 hours (34.1 hours was found with spindown at 0deg).
- With Seema, made frequency sweep NMR working manually.
- RTDs are fixed.
Small Angle GDH:
- Nilanga:
- Proposed a new method for momentum optimization to Vince and the Hypernuclear student.
- To solve the problem of the hole shift with Phi_tg, Jaideep will simulate fake holes thus higher order matrix elements could be used for the optimization.
- Tim:
- Talked with Wolfgang about the false asymmetry analysis.
- Using the same method as in Kevin's thesis.
Spin duality analysis:
- Patricia:
- Problem to recompile ESPACE due to LINUX upgrade: Seonho fixed it.
- BPM/raster calibration for kin.1. (all the other kinematics were already done)
- Working on adding old shower variables (= not build from tracking information) in ESPACE in order to extract the VDC efficiency.
- Checking analysis steps.
- Nilanga:
- Checking asymmetry results.
03/04/2004
Target lab:
- Lingyan:
- Try to be more familiar with EPR
- Ameya:
- Showed spindown with NMR measurements 90 minutes apart.
- Showed the neat difference between spin-up with 2 lasers and with 3 lasers.
- Working on the lifetime and AFP loss study on Queen Mary.
Small Angle GDH:
- Tim for Vince:
- showed plot with all water signal results for Spin Duality.
- Tim:
- Used method of error calculation from Hall C for BCM.
- Jaideep:
- Ran simulation to see the effect of the shift in PHI of the central ray with elastic kinematic --> it is about 5% so should be very small for the other kinematics.
Spin duality analysis:
- Patricia:
- Modified the asymmetry code to extract cross section.
- Generated cross section for all kinematics:
--> inefficiency of preshower blocks #8 and 16 caused glitches of the cross section for kin3 and kin6.
--> will look into using only the shower for these kinematics.
- Compared xs with nQFS and E94-010 data (for the lowest Q2)--> the shapes are pretty consistent but the acceptance wasn't taken into account properly (as Nilanga and Jian-Ping suggested) so had to multiply by a factor 3 nQFS to agree with the data for kin3 for example.
- Early elastic cross section: simulation and data have a 3.7% disagreement for the left arm and 6% for the right arm.
- Plan: Acceptance study, target analysis, finish detector efficiencies.
g2n:
- Kevin:
- worked on the elastic cross section by trying to make the simulation and data agree: varied the incident energy, the radiation length and the gamma constant of the spectrometers.
- working on fitting F2(3He) data because NMC fit doesn't work well for GDH data. Then will extract radiative correction from it.
(last updated: 03/06/2004, maintained by Patricia Solvignon)