User name Armstrong
Log entry time 19:26:48 on July27,2005
Entry number 149705
keyword=phase advance test
MCC has loaded new optics after FOPT studies of the Hall A line.
This should lead to good vertical phase advance.
I run a HAPPEX run (3878) - this was at 10 µA with no
target. No data seen in dithering plot - must be the low beam cut.
Try another run at 30 µA. This is run 3879.
Error on my part lead to no dithering cycle in the data (I started dithering
before the run started, and the run was not long enough to see a dither cycle
(every 8 minutes or so, says Kent).
Nonetheless, I see from the natural beam motion that the situation is still
bad: BPM4BY and BPM4AY are 100% correlated (the x's show
nice differences). Thus there is still no Y phase advance seen.
See figures below.
This is despite Jay's optics model doing a great job of predicting the response
of all the other BPMS in the Hall A line to various correcter kicks (with
FOPT). Unfortunately, the FOPT program doesn't have our 4A and 4B BPMS in the
configuration file so we can't see the effect directly in the FOPT test.