User name R. Michaels
Log entry time 16:11:36 on November15,2004
Entry number 136742
Followups:
- 136808 11/16/04 11:02 R. Michaels qasy in past 18 hours
- 136811 11/16/04 11:51 R. Michaels qasy feedback turned on
Tests of charge asymmetry (qasy) feedback. I make changes to the
IA EPICS channel during runs in progress. Start with tiny changes.
Then I tried bigger changes. Here are the data:
Time .... Run (in progress) .... IA set ....... Qasy (ppm)
14:00 .... 4692 ............ 0.1 (start) ...... ~0 +/- 100
14:03 .... 4692 ............ 0.2 .............. no signif. change
14:40 .... 4692 ............ 0.4
14:55 .... 4693 ............................... 0 +/- 100 ppm
15:10 .... 4693 ............ 4.0
15:28 .... 4694 ............................... 700 +/- 65 ppm
15:30 .... 4694 ............ 10.0
15:43 .... 4694 ............................... 1491 +/- 78 ppm
15:45 .... 4694 ............ 6.0
16:00 .... 4694 ............................... 786 +/- 69 ppm
16:09 .... 4695 ............ 0.1 (test finished. return to zero).
The slope is 147 ppm.
I will "turn on" the qasy feedback tomorrow (I must leave now).
Meanwhile, I set IA to 0.1 since this minimizes qasy.
The qasy seems pretty stable, it doesn't drift much.
Note also, the IA dynamic range is 0 - 10, hence we are near an edge.
FIGURE 1
