As I went to correct the ITMX Oplev mirrors, I found that both mirrors were placed in very different positions than the design position. Part of the reason I think was to preserve outside oplev path, and party because a counterweight was in ITMXOL1 position. I had to do following steps to correct this:

• I noted down level meter readings of the table before making any changes.
• I removed the counter weight from near the center of the table.
• I placed the Oplev mirrors in the nominal positions.
• I placed the counter weight near previous position.
• I moved a edge hanging counter weight to get back the level meter to its previous state coarsely.
• Then I used dataviewer to find the previous OSEM PD monitor values and changed ITMX PIT and YAW to come closer to those PD values. And voila, I regained the flashing on Xarm. I nudged the ITMX pit and yaw bit more to maximize it.
• I then went back to aligning the Oplevs properly.
• Then I adjusted the POP mirrors to get the beam back through center of window. This was very tricky and took a lot of time.
• Now the beam is going through near center and the oplev beams are far away enough from POP_SM5.
• On the outside table, I noted the POP beam and the oplev beam. I corrected the pit of the returning beam to get the oplev beam at nominal height on outside table.

ITMX Sat Amp is flaky

[Anchal, Paco]

During the above work, i must have kicked the cable between the vacuum flange and the satellite amplifier box for ITMX. This disconnected all the OSEMs and Coils. We tried several things to debug this and finally found that nudging the connections on Sat Amp box brought the OSEMs and coils back online. Note that the connector was not partially out or in a state that obviously showed disconnection of the pins. I'm glad we are putting in new electronics soon for the vertex optics as well.

Next steps:

• I showed Tega the returning oplev beam and the POP beam coming out of the ITMX chamber.
• The Oplev beam paths need to be adjusted.
  • The ongoing beam steering mirror is blocking the returning beam, so the ongoing path needs to be changed.
  • First setup two irises to save ingoing path.
  • Then make space for the returning beam by changing the steering mirror positions.
  • Then recover the ingoing path to the center of irises.
  • Steer the returning beam to the QPD.
  • Then maximize the flashing on XARM and center the oplev to save this position.
• POP beam needs to be directed to previous setup on far side of table.
  • The POP beam is coming out at the rising angle.
  • This is good for us if we do bit unconventional stuff and transfer the beam to other side of table at an elevated height. Given how close all the beams are coming out of the viewport, I think this is the best solution in terms of saving time.
  • Get the beam down to the old setup which was camera and photodiodes all aligned.