(Daniel, Kiwamu, Chris, Stefan)
- Using PR3 we pointed the green beam to the center of the septum view port. some pointing references for PR3:
PIT: -145, Yaw: 125 Center of septum view port, we left it there
PIT clips at -85 and -206
Yaw clips at +75 and +198
- Kiwamu moved the top periscope mirror in HAM1 up until the green beam was centered on it. The periscope yaw position agreed well with the center of view port. He then guided both the green ALS beam and the POB beam (actually IR, but we used green as alignment proxy) to ISCT1. Note that the POB beam does not yet have all its hardware, but we suspect it might be useful later. We dumped all stray beams on ISCT1, and put the green beam on H1:ALS-C_TRY_A_DC to have a reference.
- For the red beam - unlike yesterday -we were not able to get IM4 TRANS pitch to zero (using a MC move), possibly due to falling off the WFS sensors. For now we ignored this.
- We then realigned the red beam following the same procedure as yesterday. (PR3/PR2 walk keeping fringes, putting PR3 to its desired spot. PR2/IM4 walk to optimize transmitted fringes). This actually gave us a signal in the POB quads (H1:ASC-POP_A_SUM_OUT and H1:ASC-POP_B_SUM_OUT)
- Finally we also hunted and found the PRM alignment. Power recycling fringes with a power gain of about 3 are visible on both POB quadrant diodes and as stray light on the ITM cage.
- The attached alignment snapshot reflects the fully aligned power recycling cavity (incl PRM).