TITLE: 07/16 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Oli
SHIFT SUMMARY:

IFO is DOWN and in CORRECTIVE MAINTENANCE

A very dynamic day that I will try to sum up as best as I can. Check alogs 79102, 79164, 79167, 79160, 79178, 79156, their comments and the plethora of alogs about this OFI issue.

Context: IFO has been struggling to lock due to what we think is an OFI issue. The plan today was to test out our movement of SR3 in the +Y direction to see if we can get to NLN to the point of potentially delaying a vent to fix/replace the OFI. Here’s what happened next:

14:30 UTC (Shift Start): Tuesday Maintenance had been canceled, Sheila and I were moving the IFO up in the new SR3 +Y position but losing lock repeatedly at around ENGAGE_ASC_FOR_FULL_IFO. This happened for a few hours. Allowed maintenance activities happened (technical cleaning, HVAC stuff, NORCO delivery).

14:30 - 18:00 UTC: 3 IPA tour groups came in as expected. They went to the LVEA, which disrupted locking activities so we waited a bit until they were out.

18:26 UTC: We finally reach NLN for the first time since Friday. The range is low at around 130 MPc. Tuning, measurement and assessment of the IFO alignment begins. The alignment doesn’t look fantastic but we are NLN.

19:14 to 19:37 UTC: I take a calibration sweep by Sheila’s request since it seems that we are not well calibrated only to find out that simulines is broken and that there is no way to generate the report even for broadband on its own. Calibration team takes a look at this very briefly, confirm that the kappa c is 90% so we’re calibrated enough. Then, we discover a newer, more pressing problem.

~20:00 UTC: Keita and Sheila realize that there is only 80% of the beam power making it to sensors (table comments to alog 79160). This then took priority because it meant that should we lose lock, there could be damage to the IFO in unknown ways, including to the pressure. A quick discussion was had and commissioners agreed to manual over to ADJUST_POWER (20:31 UTC) and then slowly bring the power down until we can safely unlock the IFO. Until..

20:32 UTC: Lockloss. Sheila adjusted the power by only 1W down to 59W and we lost lock immediately. The cause for this is generally unknown but it meant we are now unlocked and need to check quickly for damage. Janos and the Vacuum team were called in to check the pressures for any glitches or spikes and thankfully, everything was okay on that front.

21:00 UTC: LVEA transitioned to LASER HAZARD per WP 11979 for SQZ work primarily.

22:00 UTC: After the SQZ work, a meeting was called to discuss next steps, specifically with respect to venting. IFO has been DOWN since then.
23:00 UTC: Prep is being done to vent, such as activating the purg

LOG: