User name paschke
Log entry time 00:41:27 on July17,2003
Entry number 104160
keyword=charge asymmetry feedback ready
I configured the source RWP to reduce charge asymmetry for Hall A.
Quick scan, run 3308:
RWP EvLo:EvHi Aq
7000 0:900 2580
6000 1200:5600 2740
5000 6800:11000 -980
5250 12000:end -60
Halls B and C were informed before this was done, and when it was over.
Hall B saw Aq changes on order of +/- 1000 ppm, so this was rather smooth.
The whole procedure took about 1/2 hour.
Feedback has been turned on and is working well, even without a fresh IA
calibration. We should continue to exercise feedback as possible, even
during optics studies, in order to keep the system working and the beam
ready to go for production.
We should also pay attention to charge asymmetry the first time the IHWP state
is toggled (IHWP is OUT right now). In principle, the charge asymmetry with
IHWP=IN could be different, but it should be easily within reach of the feedback.
For completeness, the Pockels cell voltages are: Pos=7.383, Neg=7.518.