Sheila, Keita
I went to ISCT1 and Keita aligned PRM. We saw the beam on the periscope, it was making it to the camera. The camera normally gets the transmission through an HR steering mirror pointed at REFLAIR B, this was moved out of the way during in chamber work so the camera could be used. When I put this back in it deflects the beam, so it is no longer on the camera. I think we need two people to realign this camera.
I aligned REFLAIR A + B. REFLAIR A has two ND filters on it that make it easy to align some kind of glint to the diode.
In O4, in the guardian state 101 which is DRMI locking (2W input, PRM aligned), REFLAIR B had 6 counts DC, REFL AIR A was about 2 counts. Now REFLAIR A is 1.8 counts, but REFLAIR B is 3.6 counts. So we should revisit the alignment of REFLAIR B.
Before Sheila put back the splitters for REFLAIR sensors, the ISCT1 REFL camera showed a dark blob with somewhat lighter background (or, more like dark background with even darker blob) as soon as PRM was alighned. I assumed that the beam was not hitting the camera, but when we reduced the camera gain and exposure at the same time, it turned out that the dark blob was actually the beam. Too much light seems to make the camera go in a weird state.
Anyway, this means that the path from PRM to ISCT1 is still close to where it was when in air.
Even though the camera path (with the splitters for REFLAIR sensors in place) is not yet done, we can work on the PRM parking position if we want.