L.Dartez, S. Dwyer, M. Nakano

Continuing from alog 91450, I started using awg to raster the im4 alignment to find the IR beam on the ISCT1 REFL camera on Friday. This effort was paused at the end of the day without finding the beam. This morning, Masayuki and Sheila noticed that the AS AIR camera had a beam but it was off-center. They walked it back using PR2 and IM4 and adjusted PR3 and the BS to compensate. 

When I got in to the control room I adjusted IM4 further to center the beam on ASC-POP_A. ASC-POP_B is still off center but we're choosing to prefer that POP_A stays centered for now.

Later this morning, Masayuki and I decided to see if we could find a PR2 + PR3 + PM1 alignment that 1.) maximizes LSC-POP, 2.) maintains the beam centered on ASC-POP_X, and 3.) maintains the beam center on the ISCT1 REFL camera. Starting from the nominal position (e.g. the position it was already in before we started) we moved PR2 in each direction. Each trial move's procedure was as follows: 1.) move PR2, 2.) compensate with PR3 to recenter ISCT1 REFL camera, 3.) adjust PM1 to center onto POP_X, 4.) observe/record the LSC POP counts.

We currently have roughly 3.4 counts on ASC-POP_X NSUM and 2.7 counts on LSC POP with POP_X centered within about 0.15 and 0.1 counts for PIT and YAW, respectively.

The slider values for PM1 are in PM1_sliders.png and the sliders for PR2,PR3, and IM4 are in IFO_sliders.png.

This new alignment configuration should better position us for the arm peak taking place this week, since we can confirm that we have red beam down to the ISCT1 table and on POP_X. The next intermediate step here will be to lock PRMI...