Daniel, Sheila, Corey, Keita

Here are some comparisons of power build ups on POPAIR B:

Tony and Ryan Crouch found time for PRMI + DRMI without the arms from before the BS swap using state counter, they are writting an alog about that. 

We seem to now get more of an increase in build ups that we would expect from locking the arms, and we have more light on the diode than in O4.  We do not know if we might have had clipping in this in air path during O4. 

Some changes:

• leaving SRCL offset on for TR_CARM transition seems to help.  I have commented out line 1163 in ISC_DRMI, so the SRCL offset will stay on until we manually turn it off.  It may be better to use a larger offset, like -1200 counts.  
• With DRMI locked, after Corey fine tuned the alignment, we moved the SRCL offset around.  POP90 changes with the SRCL offset as shown in the attached screenshot. It seems like we need to keep POP18 above 200 counts to have a smooth time with the TR_CARM transition. 
• Moving the ALS COMM VCO a bit closer before starting the TR_CARM transition seems to help (-100 Hz offset instead of -200 Hz).  (this change is in lscparams).  
• PR3 jumped, 92170.  After this Corey put it back according to the top mass osems and then realigned MICH and PRX.  After this the build ups in DRMI were lower, but they were also more stable and we didn't have as much mode hopping.  
• We were able to go to the start_TR_CARM state, and with the above changes the guardian was able to once do this without intervention.  This means we can servo the arm transmitted powers, but something seems not stable here.  
• I tried to measure the TR_CARM loop gain, but the coherence is too low with the settings in our usual template (userapps/lsc/CARM/TR_CARM has excitation amplitude of 1).  I increased the loop gain by putting a 3 in TR_CARM where there is normally a 1, and increased the amplitude to 10.  We lost lock for an unknown reason, not the measurement.
• locking PRMI and DRMI has been slow.  Here is an old alog about the trigger levels 44348  When we ahave DRMI locked the MICH TRIG MONITOR (POP 18 norm) is around 100, based on this old alog I manually changed the trigger threshold to 27 and this seemed to help PRMI lock.  I've only tried this once and didn't put it in the guardian.  
• We are able to to strat_TR_CARM, with the SRCL offset on, then add a factor of 3 gain (in the input matrix or TR_CARM) and then step the TR_CARM offset to -0.8 without looseing lock.  I was only able to get a poor coherence measurement but it seems like this may have a ugf close to 100 Hz.  I do not understand why this is not stable, and stepping down the ALS gain seems to cause locklosses or large glitches.