Log entry time 18:09:11 on June19,2004

Entry number 126343

Followups:

• 126460 06/21/04 00:08 Seonho Choi Changing Hall C IA set point

We should try to zero the Hall C charge asymmetry after every couple
runs, or anytime it seems to be getting big.  We won't need to do this
once we get the automated feedback working for Hall C.

How to zero the Hall C charge asymmetry:

Analyze the most recent (or current, if it has enough statistics) run:

as apar on adaql5 or adaql6:
> gopan
> pan -r ####   (where #### is run number)

Check the charge asymmetry:

> pan
root [0]  open(####)
root [1]  P->Draw("asym_bcm10","ok_cut&&evt_bcm10>0.0015")

Check the mean for this histogram. (Also, the plot should not be 
absurd, with a beam at -1000000 or something like that.)

The new HALL C IA setpoint is calculated as:

(new IA) = (old IA) - mean / 1250