User name R. Michaels
Log entry time 21:22:12 on October 11,1998
Entry number 2677
This entry is a followup to: 2671
keyword=charge asymmetry testSpectrometer DAQ run 1704
Happex DAQ run 8081
Moller DAQ run 4021
Measurements of Charge Asymmetry at waveplate position 48
which is optimum, or near optimum.
Results: Happex says Qasy = +0.28 +/- 0.005% (error probably bigger)
Moller says 0.29 +/- 0.02%
pscaler (q10) says 0.45 % (error basically unknown)
The relative signs of these asymmetries is not firmly
established. The spectrometer scalers have unkown
offsets (with beam off) that need to be subtracted.
The disagreement with pscaler is disturbing.
Below are helicity correlated beam position differences
at various places: the point of highest dispersion in
the arc (giving the energy diff), and the BPMs near target.
FIGURE 1
