Sheila, Gabriele, Corey, Jennie, others
- Based on the alog from last night, we decided to start with an initial alingment, using the camera set points that were set yesterday based on the baffle PD alignment. This went smoothly, and allowed us to lock to PRE_ASC_FOR_FULL_IFO several times.
- We undid some guardian changes from yesterday, we removed all DRMI ASC except MICH, and put the DHARD gain increase in DHARD_WFS back in.
- We realized that we have been loosing lock because the ALS DIFF guardian was thinking that we lost lock (when we skip shuttering ALS this checker doesn't get disabled). I've added IDLE states to both ALS_DIFF and ALS_COMM, for now we are manually selecting these when we get past the ALS steps of the CARM offset reduction.
- After that, we are able to sit and walk alignments for longer in PREP_ASC_FOR_FULL_IFO. We lost lock as we moved CHARD P in the negative direction which was improving the PRG, but in the last seconds of the lock POP90 was increasing. Our next plan is to turn off MICH ASC while we walk alignment.
Summary of guardian changes that are useful to make when we are recovering from a vent, for future reference:
- bypass shuttering of ALS in CARM offset reduction by changing wieghts of connections, this allows us to reset the green references when we lock.
- Greatly extend the timer for INCREASE_FLASHES
- change connection weights to go through CHECK SDF rather than SDF revert (if this is what we want)
- we are thinking about the check for giving up on DRMI and moving to PRMI, the logic we have worked well during O4a so we are hesititant about changing it. A workaround for if it is switching to DRMI when we don't want that is to pause ISC_LOCK and let the DRMI guardian lock DRMI.
Some guardian changes made yesterday to think about maybe reverting:
- got rid of DHARD gain reduction at DHARD WFS
- added SRC1 back to DRMI ASC
- change of ALS normaliztion to Y arm.
We increased the ITMY camera exposure (H1:VID-CAM23_EXP) from 30 to try to see the beam location once we're in resonance.
Comparing the ITMY camera (intra-cavity) from last lock in O4a to now, beam position seems similar in pitch, slightly more right in yaw. Caveats: as we have a dimmer beam X/Y reported position may be more effected by scatted light, and we are comparing different locking states (500 before, 300-400 now) plot attached.
I added a new state to the ISC_LOCK guardian called IDLE_ALS, which sets ALS_DIFF and ALS_COMM to IDLE, as shown in the attached graph. This can be used to avoid shuttering ALS, but when we are finished with resetting the green reference we can set the weight to not use this path any longer.
As we have been moving alignments today, we have unlocked the green arms. The ALS_XARM and ALS_YARM guardians have a fault checker in the LOCKED_IR state that checks the beckhoff ALS PDH fault checker, which checks things related to the green PHD. This causes the guardian to try to relock the green arm, and if it suceeds it can turn the green WFS back on, which caused us some confusion today. I've removed this fault checker.
In this situation, we need to turn on the script that adjusts the QPD offsets to keep the green aligned to the arm while we move the arm alignments, this can be done once the ALS_ARM guardians are in RED_LOCKED and the green WFS are off.