Log entry time 12:35:35 on July18,2004

Entry number 128852

Followups:

• 128853 07/18/04 13:03 paschke Hall C charge asymmetry

I can't remember if this is clearly known or not.  The effect
of Hall C on the Hall A beam is seen below.  The Hall A IA cell runs steadily 
around 2 V when C is on, and when C turns off, feedback
adjusts the IA cell by about 1.6 V (about 320 ppm). 

This, despite the fact that the Hall C charge asymmetry was not large
(steady about about 100 ppm during the run, see Figure 2).  Why is our charge 
asymmetry so sensitive to Hall C beam?

And the second mystery: why did the Hall C auto feedback not work?  The Hall C 
IA cell was nearly, but not quite, railed; the epics readback was constant at 
9.9 for the entire run.  Does Hall C feedback shy away from the number 10?