I tweaked up the MZ alignment. The reflection had been around 0.550, which kept the MEDM indicator green, but was still too high. I fiddled with BS1, and a little bit with BS2. When I had the doors of the PSL table open, I got as low as 0.320. When I closed up and came back to the control room, the MZ refl had drifted up to 0.354. But it's good again now.
In the future, mirrors shouldn't be so close together that you can't get at their knobs to adjust them No good. I ended up blocking the beam coming out of the PMC to prevent sticking my hand in some beam, making the adjustment, then removing the dump. It worked in a safe way, but it was obnoxious. |