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User name paschke/snyder
Log entry time 19:42:43 on June22,2004
Entry number 126663
keyword=opportunistic source studies
CHL crash, so opportunistic source studies in the 100 keV region.
We set the bpm gains in crate iocse11 to match the gains we used
in studies May 25th. At that time, the bpms were fine with 40 uA,
but most are "unlocked" (signals are too low) even though we are
running 50 uA. Strange. Our data looks fine, by the way, so I
guess I won't worry about it.
There was a spot move this morning also, so getting 50 uA was no
problem. By the end of the tests (about 2.5 hours?) the current had
dropped to 40 uA!
Run 2371 - checking BPMs in injector, changed PC voltages at end of run.
Run 2372 - PITA scan, IHWP=OUT, RHWP=2250, PC centered on "ideal" voltages:
Delta PC pos PC neg
-------------------------
0 5.405 6.388
100 7.072 4.721
200 8.739 3.054
-100 3.738 8.055
-200 2.071 9.722
Results: PITA slope approx. -3.4 ppm/Volt.
1I02 DeltaX about .57 nm/V, DeltaY about -0.3 nm/V
Run 2373 - killed to restart et_server. Went to Beam line configuration.
Run 2374 - RHWP scan (IHWP=OUT, PC pos=5.405, new=6.388)
results: charge asymmetry shape about as expected. Position
differences large (1 um in 1I02, 2 um in 1I04) and pretty much
no response to RHWP at all.
Run 2375 - RHWP scan, with 100 V PITA offset (IHWP=OUT, PC pos= 7.072, neg=4.721)
results: position sensitivity to RHWP, but around 1/3 that of
the "constant" position difference offset (for x, much
less sensitivity for delta y).
Run 2376 - IHWP->IN, PITA scan. centered on "ideal" PC voltages,
RHWP=6500
Delta PC pos PC neg
-----------------------
0 3.931 6.658
100 5.598 4.991
200 7.265 3.324
-100 2.264 8.325
-200 0.597 9.992
results: slope in Aq =10.6 ppm/V,
at bpm1I02 position diff slopes are DeltaX = -2.2nm/V, DeltaY = 1.3nm/V
Run 2377 - RHWP scan (IHWP=IN, PC pos = 3.931, PC neg = 6.658)
this was interrupted after scanning 130->180 degrees, as the CHL
was returning and they were ready to use the beam.
results: large position differences remain, comparable to IHWP=out
scans. Position differences are again totally insensitive to
RHWP angle.