Stefan, Craig, Georgia, Sheila

Locking

• We understood why we were having trouble with tidal last night, it was a tricky feature of some recent changes to the ALS ARM guardians.  Craig has added some new states called TRANSITION in the ALS ARM guardians to avoid this confusion in the future. 
• We had slow DRMI acquisitions.  Here is a summary of the changes we made:
  • Georgia found that the MICH trigger level had been lowered since 2 weeks ago, we raised it back to 40, and teh MICH trigger delay we set back to 0.3 seconds as it was 2 weeks ago. 
  • We wathced a few failed locks, and decided that when the SRCL control gets ramped on it kocks MICH out of lock.  We increased the RAMP time on the +106dB filter for SRCL to 0.3 seconds from 0.1 second. 
  • After this we had one DRMI lock within 2 minutes. 
• The contrast defect with our new 30W pre-loading TCS is 0.38%
• The violin modes are being damped by the guardain right now.  The other day Jeff K and I found that ITMY MODE7 wasn't damped with the settings in the guardian (-gain), but we were able to damp it with + gain -60 degrees.  Tonight this didn't work, now it is back to positive gain, no phase. 

Alignment

• Today initial alignment was giving us very bad recycling gain, so Hang adjusted teh soft DOFs by hand while we weer sitting at a TR_CARM offset of 40 to increase the refl power.  That allowed us to lock, but we clearly saw a CSOFT P instability at 2W (there was no CSOFT feedback on.... )  turning on the WFS which are engaged in REFL_POP_WFS improved the recycling gain and stopped the oscillation. 
• We had to reduce the gain of CHARD (removing FM1 which is +46dB for P and +30dB for Y) to avoid a slowly growing but very large oscillation in the POP power, REFL camera, and AS camera.  We also lowered the gain of SRC1+SRC2 by 20dB, because a slow oscillation in these was capable of breaking the lock.)  These changes are in th guardian. 
• Since we weren't able to lock with the alignment that Initial alignment gave us, we ran the scripts that set the QPD offsets, and reset the camera references.  Some of the QPD offsets are large enough that we should pico them, but we are reluctant to pico them here since we aren't sure why things would have changed compared to the references that worked before the TCS work. We also didn't accept these into SDF. 
• We phased AS36 to maximize the BS signal in Q. We also phased AS72 to get the DC signal into I, but these were only small changes. 
• We found that the POP QPD offsets were changes 2 days ago, we don't know why so we tried reverting them which resulted in a better recycling gain. 
• With the low gain in CHARD and SRC, engaging the SOFT loops is dangerous.  We would attempt to increase those gains, but until we have we had to move the arms by hand to bring the error signals close to zero before engaging them. 
• We are running the A2L script to check our spot positions. 
• Attached is a screenshot of our AS camera, which looks bad.