TITLE: 07/22 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 10mph Gusts, 7mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.07 μm/s
QUICK SUMMARY:

Verbals has a Check PSL Chiller alert from 14:22 UTC

IFO currently down for OFI maintenance. 

Expected work today:

H6 - Continue inspection of WFS and shutter (take photo with fast shutter up).
Start setup AUX laser systems, prioritize HAM5 alignment laser

Confirm pointing still retained settings, oplev.
Using SQZ beam delivered from HAM7, make OFI Measurements in-situ:
Measure loss after each component inc. SRM with power meter.
Get Danny signoff on updated AUX SOP
Finish Setup AUX laser system in HAM5, use SR
Group mtg to determine OFI optic swap order of operations.

Sun Jul 21 08:06:17 2024 INFO: Fill completed in 6min 13secs

Over the past few days the MX weather station has been reporting diminished high temps. The attached plot shows all four out-building weather station temps, MX is in red.

Sat Jul 20 08:05:07 2024 INFO: Fill completed in 5min 3secs

TCs spiked to below the trip temps, but didn't flatten out. Pressure spike looks normal though.

After everyone was done at HAM5/6/7 chambers, and with soft covers on HAM5 and HAM6, I closed the purge air to HAM7 and closed the relay tube gate valve, aluminum foil was restored to cover the entire bellows port.  HAM6 purge was closed via its purge valve.

HAM5 and HAM6 are currently being purged on a dialed back flow from the purge valve near HAM4 that feeds the ourput mode cleaner tube, soft covers are billowing out.  Flow needs to be restored before any activities take place on any of the 3 chambers.

AUX laser that is to be injected in HAM5 from SRM HR side for later alignment work was prepared in the lab. It's smaller than the real IFO beam but it will do OK. In the 1st attachment, left is the SRM transmission path, green is measured in the lab, red is a fit, blue is the IFO. Assumption was made that the distance from SRM HR to the collimator telescope of the laser is 1.5m, it turns out that it's probably more like 2m or so, but it's not a huge deal. Right is the SRM reflection going to SR2.

We placed the telescope, a metal mirror and a BS roughly in place in HAM5 but didn't adjust it because SOP was not fully signed in time. We left these components inside and closed the chamber for today.

TITLE: 07/19 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
SHIFT SUMMARY:

16:25 UTC HA:M4 and HAM7 ISI are Isolated.
HAM 7 Tripp. 18:02 UTC

Untripped an SRM watch dog.
 
Inchamber work started to happen today:

See Camilla's Alog shows that the Fast Shutter has been exposed to high temperatures and colorization.

Camilla and Jenne W. have been working on SQZ QPD centering. Seems like SQZr team now has light on their PDs again and will return on monday to continue their work.

HAM7 inchamber crew (TJ and Kieta) came out of chamber after installing the AUX laser but have not turned it on.

Gerardo is going into the LVEA to close up the HAM entries with temporary covers to minimize contamination.

Atomic clock failed again, Daniel is currently addressing that issue.

LOG:

This morning, TJ and I took FTIR samples of aras around the HAM5 OFI KTP burn event area and the HAM6 Fast shutter suspicious heat mark.

Report (and eventual results) posted to:  https://dcc.ligo.org/E2400268

Relative Humidity reader on the table inside of HAM5 was reading 5% when we got in, 9% an hour into work with the cover open, 2 people.

Vicky, Camilla

Took ZM4,5,6, SRM alignment and PSAMs back to their values on 2024/07/17 20:18 to 20:23 UTC as in 79193. Plot here. We hope this will allow the SQZ beam through the OFI.  SDFs for ZMs attached but not saved (incase we want to revert them if SQZ beam not seen), SRM optical align alignments were 2240, -3436 before as not svn monitored.  SRM WD was tripped, Tony reset this.

SQZ OPO is seed dither locked but I can't see the most of the beam power on the SQZT7 diode. Vicky pointed out I should use the RLF QPDs to check for FC1, ZM1,2,3 pointing, they looked bad but there was some light on the QPDs, moved alignment sliders to get the FC1, ZM1,2,3 osems to be the same as 2024/07/17 20:18 to 20:23 UTC. This made the beam completely off the QPDs so I reverted, plot and sdf attached. We started walking the beam with FC1 and ZM3 as in 75509. Then Daniel asked if we had the TECs on...d'oh. after the TECs were turned on we had the QPDs saturating and I reverted all ZM1,2,3 and FC1 changes.

After lunch: Can reduce SEED power and check centering on QPDs. Can open SQZT7 and check the beam is going though the irises.

Rick Savage, Dan Chen, Shingo Hido, Emmanuel Makelele and Dripta.

We went down to EY on Thursday, July 18th, 2024 to do a Pcal measurement, mostly to show the measurement procedure to our visitors. We used the procedure outlined in T1500062-V17 as a guide. A scanned copy of the filled out measurement procedures and log is attached.

Before we began the measurement, a picture of the beam spot position was taken. It shows that the beams were centered on the Rx sensor apreture (BeamSpotBefore photo attached).  

As noted in the scanned copy, after the first background measurement while WS was placed in the Tx module, the shutter stopped working. We could not open the shutter locally or remotely. The shutter has now been removed from the EY Tx module for troubleshooting. Pictures attached.

We continued with the measurement manually shuttering and unshuttering the laser. After taking all the measurements, a beam position picture was taken. It shows that the bemas remained centered and the Pcal beam spots did not drift significantly during the measurements (BeamSpotsAfter photo attached). 

Analysis and results/plots to follow. 

Conda packages updated on workstations.  diaggui was updated to version 4.1.3, fixing a bug in  excitation channel name nesting that could cause the excitation channel selection box to inadequatly nest channel names.

TJ has Transitioned the LVEA into LASER HAZARD for Work Permit:

This morning I took a dew point measurement of the corner station purge air at the purge valve for the output mode cleaner tube, the following chambers were using the purge air, HAM5 with two soft covers on, and HAM6 with one soft cover.  HAM7 was not drawing any purge air.

Dew point measurement is -41.5 ^oC.

Sheila, Betsy, Camilla

With the HAM6 +X door off we did an initial inspection of HAM6, looking for anything that could have caused the pressure spikes seen in 78346, 78432. 

There was discoloration on the fast shutter, see lower half of the -X part of the "fast shutter cap" and viton piece: part (4) and  (10) of D1003318. Photos attached.  This was the only thing we could see out of the ordinary. 

From the Feb 2024 HAM6 closeout photos in 75791, this photo shows the fast shutter and no discoloration can be seen. 

We'll plan to inspect the fast shutter when closed today.

Mitchell R, TJ S.

We removed the one +X panel, three of the top panels, the +Y panel, and one on the -X side. This should give enough room to work on the OFI below and get power meters into all places needed.

Some panels had minor blemishes on them, I'll have to reference the photos we took when installing to make sure they aren't new.

Dust counts when entering chamber were 0's or 10. They were checked periodically with similar readings.

Spare optic SRM07 arrived at LHO yesterday from LLO, after prisms were bonded to it's sides (see LLO alog 71969 for details). After inspecting the optic in bonding lab, I started preparing for bonding the magnet-standoff on the AR side. At first I prepared 8-10 magnet-standoff of both north and south polarity. The magnets were glued to the standoffs using Masterbond EP-30 - as per assembly drawing D0902432_V2.

The optic with AR side facing up (arrow at the top of the optic points towards the HR side) was placed on the gluing jig and aligned with the scribe lines. Once the edge of the optic was well aligned with the jig, metal plungers with the magnet-standoffs were inserted inside (the jig) - after applying the Masterbond EP-30 to the bottom tip of the standoffs using a pin (for reference see pic here). This set up was left for curing for 24hrs approximately, following which the jigs were removed. Given below are the details with pictures for reference,

- SRM07 arrived at LHO in pelican case - image01.

- optic inside the transport can - image02

- optic placed on the optical bench for inspection - image03

- Metal jig were placed on top of the AR side of the optic and aligned with the scribe lines and the optic edge (locked with stops having silica tip ends)- image04

- magnet-standoffs with plungers inserted into the jigs - image05

- magnet standoff prepared in lab - image06

- jigs removed and SRM07 with magnets glued to its AR side is visible - image07 and image08

- Optic with labels showing the four magnets and their polarity - image09 - see controls arrangement poster for reference.

Looks like there is visible damage on the KTP optic of the OFI.

TBC...

I ran the DARM offset step code starting at:

2024 Jun 13 16:13:20 UTC (GPS 1402330418)

Before recording this time stamp it records the PCAL current line settings and makes sure notches for 2 PCAL frequencies are set in the DARM2 filter bank.

It then puts all the PCAL power into these lines at 410.3 and 255Hz (giving them both a height of 4000 counts), and measures the current DARM offset value.

It then steps the DARM offset and waits for 120s each time.

The script stopped at 2024 Jun 13 16:27:48 UTC (GPS 1402331286).

In the analysis the PCAL lines can be used to calculate how the optical gain changes at each offset.

See the attached traces, where you can see that H1:OMC-READOUT_X0_OFFSET is stepped and the OMC-DCPD_SUM and ASC-AS_C respond to this change.

Watch this space for analysed data.

The script sets all the PCAL settings back to nominal after the test from the record it ook at the start.

The script lives here:

/ligo/gitcommon/labutils/darm_offset_step/auto_darm_offset_step.py

The data lives here:

/ligo/gitcommon/labutils/darm_offset_step/data/darm_offset_steps_2024_Jun_13_16_13_20_UTC.txt