corey.gray@LIGO.ORG - posted 01:52, Monday 27 January 2020 - last comment - 04:32, Monday 27 January 2020(54738)
H1 Locking Notes (Running Log Of How It's Going During Tonight's Graveyard)
Started off locking attempts this shift, but taking H1 to DOWN.
Initial Observations:
- Green Arm alignment looks great.
- Able to get to CHECK_IR w/ no issues.
- DRMI didn't lock on first attempt.
- PRMI locked up fairly quickly.
- Not sure if this is noteworthy, but while attempting to go to PRMI_ASC, the ISC_DRMI node seemed to be stuck in PRMI_ASC and would not get to OFFLOAD_PRMI_ASC. The log was going made saying several signals had not converged (i.e. MICH Pit, PRC1 Yaw, PRC1 Pit Error Signal). On the Control ndscopes on the wall, they looked like they reached a convergence (or atleast were close).
- After about 10-15min later, I had to taoke ISC_LOCK to MANUAL & go to PRMI_TO_DRMI_TRANSITION
- But are we now skipping the OFFLOAD_PRMI_ASC step?
- DRMI did not lock.
- CHECK_MICH_FRINGES continues to have issues where it appears to no longer lock on a dark fringe, so it is no longer clear what one should do with the BS. (but with that said, the BS should be fairly aligned since the PRMI readily locks). But it would be nice to have CHECK_MICH_FRINGES return to its normal operations.
- Gave up on CHECK MICH FRINGES and went to PRMI: it locked up almost immediately
- Unfortunately, continue to have the same issue where PRMI_ASC is stuck waiting for ASC signals to converge. 1st Attachement is a snapshot of the IR cavity Init Align ndscope & on this INP2_P looks like it increases from 0 to 0.4 and it just stays there. Does this need to converge?
- Since stuck at PRMI_ASC, took ISC_DRMI to AUTO, and then went MANUAL from PRMI ASC --> OFFLOAD PRMI ASC & then PRMI ASC OFFLOADED. Then let took ISC_DRMI back to MANAGED.
- ISC_LOCK then took over and tried locking DRMI. First 1-2min looked ugly, so I clicked SRM in negative Pit moves & observed.
- DRMI Locked!
- Made it to OFFLOAD DRMI ASC.
- While typing this alog, noticed POP 90 & 18 both took HUGE shifts(!). ASC luckily caught this, and restored, but what was this about?? (see 2nd attachement).
- LOCKLOSS immediately as soon as I went to next state: CHECK AS SHUTTERS!!
This is going to be a long night.
Images attached to this report
Comments related to this report
NOTE: winds have picked up with gusts over 40mph in the last 30min.
After lockloss at CHECK AS SHUTTERS:
- 9:56 (1:56am local) Took SEI_DIFF from FULL to CORNER.
- DRMI locked after I intervened by moving SRM in pitch (by ~-9.0 units)
- The POP 18/90 drop/shift might be happening during OFFLOAD DRMI_ASC (perhaps due to issues at PRMI?)
- CHECK AS SHUTTERS takes pop18/90 into oscillations (drops POP18).
Attached is snapshot of ndscope. The two spots to look at are when pop18 (pink) & 90 (green) go into oscilations/drop:
- 1st drop: during OFFLOAD DRMI ASC
- 2nd drop: during CHECK AS SHUTTERS.
I'm not used to seeing these effects. What's different??
Images attached to this comment
Selected NOMINAL LOW NOISE & waited to see how it goes (also crossed fingers). Jeff last made it to LOW NOISE ASC...Hoping to get that far!!
- 10:10 - 10:15 MOVE SPOTS
- Lockloss at LOW NOISE ASC.
- This is where I expected a lockloss to happen since Jeff had a lockloss here, and ASC Land hasn't looked happy from PRMI/DRMI.
At a wits end now. Will try an Initial Alignment next.
11:14 Initial Alignment run and successfully completed.
After an Initial Alignment.
- DRMI didn't lock. Noticed short locks...wondering if this could be a triggering threshold issue?
- PRMI locked within 2-mins, but still seeing issue of signals not converging & hence being stuck in this step.
- Took over 12min waiting for signals to converge (i.e. MICH_P took a step up and looked like it was very slowly coming down. Wondering if PRMI just timed out? (Because I did not want to intervene this time.)).
- DRMI locked in about 3min.
- Lockloss at LOW NOISE ASC again.