User name V. Sulkosky
Log entry time 05:22:12 on June29,2004
Entry number 127325
keyword=Hall C IA setpoint changes during run 2523
At the end of Run # 2522, the Hall C Aq had increased to 100 ppm. We decided to wait until the next run to change the IA. However at the start of Run # 2523, the Hall C Aq was around 250 ppm. I had to reduce the Hall C IA from 6.267 to 5.947 to zero the charge asymmetry.
During the first 50k events of this run, the Hall C Aq was greater than 100 ppm. Now the Hall C Aq is below 75 ppm and is continuing to drop.
It appears that when the Hall C beam trips off the charge asymmetry changes, forcing us to change the Hall C IA to compensate.