On Monday I had a good alignment for the FC, see 89694 and that alog's attached screenshot. Yesterday we went there and had to touch up FCs a little to get flashes. Today for the same sliders was even worse witha very PIT misalinged FC Green beam, see attached, in the same FC1 PIT slider potion, the osems were 150urad off, attached. When I brought us back to the top mass osem positions for all optics (ZM1,2,3,FC1,2 and ZM2 PSAMS) we have no green flashes in the FC, just a single pass green beam, attached.
- Why is the FC1 top mass osems drifting 150urd in 24 hours
- We don't seem to be able to trust the osems as going back to them gives us no FC flashes.
Rahul did in-air TF's 75830
Rahul found that this was because the LVEA temp around HAM7 had increased ~3degF. Betsy , Geradro noticed this was as the Megacleanroom had been turned on. Richard is now turning it off.
As the temperature returned to normal with the mega clean room being turned off, our flashes degraded again. I again tried going back to the FC1 osems and the FC flashes disappeared, first attached t-cursor. I then tried going to the bottom mass WIT channels, which went the opposite direction to the osems, here the flashes were lower than when we started, second attached t-cursor. This makes us think that the best flashes are for the same slider values.
