Jennie W, Keita, Rahul

Today the three of us went into the optics lab to upgrade unit S1202965 with the c'bore washer and qpd clamp plate that give a ~ 2 degree tilt between the QPD plane and the mount plate. See detail D in D1300720.

Looking at the assy solidworks file, LIGO-D1101059, if the back face of the photodiode array is facing to the back, the longer clamp leg points towards the front, and the notch on the tilt washer should be approx at the 4o'clock position.

We first checked the alignment into the array photodiodes currently and realised the beam was off by a large amount in yaw from the entrance aperture.

Keita had to change the mounts for the PZT mirror and lens as these were slightly tilted on the translation stage and it seemed like we needed some more robust alignment setup.

We then tried aligning with the upstream steering mirror and PZT mirror but can see multiple beams on each array PD. To check that the beam is not too large at the input aperture we want to re-profile the beam size on the way into the ISS assembly.

We left the set-up with the M2MS beam prolfer set up at the corner of the table and rough alignment of the beam into it, more fine adjustment needs to be done.