Cheryl, Kiwamu, Sheila
This morning Cheryl went into the PSL and saw that the rejected beam from the thin film polarizer after the rotation stage was hitting the edge of the steering mirror which sends it to a beam dump. (She has nice photos of this). This aftrernoon she, Kiwamu and I went into the PSL to fix this.
We first adjusted the position of the iris after the bottom periscope mirror, and added two steering mirrors, and iris and a beam dump to the path to the OSA so that we would have good alingment references for the beam leaving the table. We then turned the power down before the PMC, and using base plates as markers moved the entire TFP assembly 5 mm closer to HAM1. Kiwamu took some photos of the resulting beam position on the steering mirror which are on Cheryl's camera. The beam was then high on the beam dump apperature, so we changed the spacer in the beam dump mount for a thicker one. We turned the power back up, and checked the beam on the irises and the persicope PD.
Cheryl's photos from this morning suggested that there could be clipping on the output apperature of the EOM. We tried to determine if this was clipping or a back reflection, but can't say for sure. Now we are out of the PSL, the IMC relocked without problems, and Jeff B has started inital alingment.
Kiwamu's image of the beam nicely centered after he and Sheila moved the houseing for the Thin Film Polarizers and the steering mirror.