Meeting #121
Moeller Measurements:
During the E05-102 experiment we did only four Moller measurements, all in May,
while we are analyzing data that were collected in June. Not having a single
beam polarization measurement made me very uncomfortable. Therefore, I tried to
learn something about our beam polarization from Hall-B Moller mesaurements.
Although Hall-B errors are probably larger than claimed, we still want to
use them, because it is better to have "bad" measurements than none.
Looking at the web-page (http://clasweb.jlab.org/cgi-bin/spin_rotation/spin_rotation.pl?a_passes=2&b_passes=5&linac_energy=1180.565&polarized_halls=1) I learned
that we were running at the sweet spot, meaning, that accelerator configuration
for Hall-A and B was such, that both halls could get maximum polarization.
This suggests, that their polarization can be directly compared to ours.
This is whay I did. I gathered all their measurements, calculated the average
value and the spread (sigma) of the measurements. Then I did the same thing
for our measurements. In the end I confronted both results:
1.)
MCEEP:
I am still working on the MCEEP simulation. I still see a 1-2deg difference
in the deuteron scattering angle (which should correspond to in-plane angle of q for
considered process d(e,e'd)), that I can not explain. MCEEP returns angles that
are too large. However, when I calculate the angle of q-vector myself, using
MCEEP information for HRS-L, I get results, that agree with data. Will continue
debugging this problem.
2.)
3.)
Last modified: 04/17/13