J Kissel S Dwyer

We now think that the IMC alignment wasn't the real problem, which we had suspected earlier today 36424.

•  Peter Jason and I went into the PSL this afternoon and moved the spots in yaw to match the two irises in the bottom periscope path).  
• Afterward Kiwamu and I realigned the IMC by moving the PZT and MC1, and Jeff picomotored to center the IMC WFS. The spots on IM4 trans and the second loop QPD are closer to where they were before the vent, but this didn't help us lock. 
• Jeff did an initial alignment
• We attempted to get through the CARM offset reduction, but saw that our recycling gain hadn't improved. We were still seeing the symptons in alog 36439
• Jeff and I used the procedure described in the comment to 29082 to co-align the red and green in the Y arm. With the Y arm locked and full green ASC engaged for the Y arm
  • ISC_LOCK to initial alignment
  • ALS_YARM to INITIAL_ALIGNMENT (Green locked, all green ASC running)
  • We locked the PSL to the Y arm (ALIGN_IFO to YARM_IR_LOCKED).  
  • Jeff continuously adjusted the beam splitter to maximize the IR transmission through the arm (LSC-TR_Y_NORM, goal is 1) while I moved the camera offsets and we waited for the green ASC loops to converge.
• We ended up changing the YAW camera offset to 397 from 367.95.  Yesterday when I first aligned the Y arm, the camera spot was near this position.   Engaging the camera servo moved the beam off the trans diode on ISCT1, so I moved the beam splitter to restore it.  What Jeff and I did today was the reverse of this procedure.  We think that the green camera reference for the Y arm has gone bad somehow (gotten bumped), so we have updated it.  We tried this procedure for pitch but ended up with the same camera and beamsplitter positions as we started with. 
• After this we redid the alignment of SR2 and SRM.  DRMI locked well, we didn't have the same problems with ASC engaging we have been having.  We did not have as large of a 10 mode at the AS port just before DHARD WFS confirming that the camera and beamsplitter move was good for the alignment of the interferometer. 
• This locking attempt we were able to get through the CARM reduction.  The first ASC loops to be engaged (REFL POP WFS) brought the recycling gain down.  Then when some further ASC loops came on (probably POP-> PRM which is ASC_PART2) we unlocked the interferometer.  
• Since that we have had several locklosses in the final steps of the CARM offset reduction sequence, but the reflected power is consistently better during the offset reduction than it was before we moved the camera reference. 

Other things tonight:

• ALS locking has been not very reliable.
• Searching for DIFF was not working well, I updated one of the offesets in alsDiffparams.dat
• the mode cleaner has not been locking well, we can lock it by puting an offset on MC2 length and taking it off again.  We might need to relook at the triggering. 
• I changed the gain for the initial alignment of the laser into the X arm, I changed INP1Y gain from -50 to -40 to get rid of an oscillation. This is in the guardian.