Sheila Varun Cao TJ Dan B Jim Georgia Patrick Jenne
This morning we were able to get to resonance by changing some gains and offsets in the CARM offset reduction.
- TJ and I moved the parameters that I changed into a dictonary in lscparams called carm offset, to make it easier to undo this and to redo it if we need to again in the future.
- We were sometimes loosing lock before making the transition to RF darm, so I moved the TR_CARM offset for the RF_DARM transition (from -5 to -3). I tried to revert this once the recyclin gain was improverd, but we kept loosing lock, so it is at -5 for now.
- We were engaging a DARM boost (FM4) part way through the CARM offset reduction, previously at -20 TR_CARM, I moved it to -12 because all the build ups became much more stable once that was engaged. Now that the recycling gain is better, this boost still seems to help stabilize build ups lower on the frigne than -20, so I have left this at -12.
- Moved the TR_CARM gain increase and boost that normally happens at -40 to -32, based on measurements of the TR_CARM OLG. (This is so far still at -32)
- We were then able to move to TR_CARM of -38, manually skip the gaurdian state that calculates the TR_CARM offset to use for the TR_REFLAIR9 transition, and do the transition to REFL9.
- We were able to go to resonance, but with a recyclcing gain of ~23 and very noisy build ups. We lost lock the first time that we locked this way attempiing the ANALOG_CARM transition.
- Watching the ASC error signals, we were able to manually move the arms (CHARD P mostly) to increase the recycling gain.
- We have had several iterations of this, closing more ASC loops each time combined with manual alignments.
- The guardian is working until ENGAGE_ASC_FOR_FULL_IFO, if we manuly skip CARM_5_PM. SRC1+SRC2 loops are commented out of ENGAGE_ASC for now.
- After our struggles with the ground moving (below) we were able to acquire lock with a recycling gain of 41, before turning on any ASC here Georgia servo'd the green QPD offsets to zero the green WFS signals, and we averaged the camera offsets to reset the inital alignment references. (1st attachment shows differences in references).
- We lost lock after this while trying to manually move SR2 +SRM to keep up with the ADS loops.
- We decided to pico on AS_C to bring the beam back onto the diode so that we can try to close some loops. We got an EQ +wind after this and decided to leave closing these loops for another day.
Seismic/ISis:
- We have tripped the BS ISI 3 times, Jim thinks that the first two were the result of an incorrect setting in the GS13s, the third trip was due to walking near the sensor correction seismometer, and tripped both ITMs as well.
- We had been runing 90mHz blends at EX, but we've had difficulty locking for the last 2 hours since the wind has been gusting to 40mph. We switched the ISI config to WINDY no BRSX, although didn't make much difference to the ETMX pit oplev, which is about 0.4urad peak to peak
- After a few hours of struggle with wind, Patrick and Jim fixed the BRSX code with some remote advice from Michael, and added it back to the sensor correction, which helped quiet down ETMX optical lever.
- Jim also turned on the differential CPS feedforward between HAM2/3 in the X direction, and between ITMX and BS in the X direction, and ITMY and BS in the Y direction. We can turn this on or off using the master switching in the lower right hand corner of the output limiters screen accessible from the yellow ISI DIFF button on the ISI_CONFIG screen. Jenne and Chiara are working on a guardian for this. Things seemed much better after this is done, but this also coincided with the wind dying down a bit.
- The wind has now picked up, forecast to go until 11pm and there is now also an EQ, so I am done for the day.
Oher locking:
- Once, we had DRMI lock just a few seconds before the DRMI timer went off, but not long enough before for the DRMI guardian to have "arrived" in the requested state. ISC_LOCK requested PRMI_ASC and unlocked DRMI. We edited this so that it will not check the timer unless DRMI is not locked.
- We also saw that after the PRMI ASC runs, the OMs get railed sometimes (operators have been pointing this out). We added a few lines in the ISC_DRMI gaurdian that will turn off the AS centering loops before attempting the transition to DRMI.