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...

WP 11989

With HAM6 and HAM7 vented, the Fast Shutter, OMC PZT, PSAM and HAM7 Piezo were powered on. Both high voltage interlock chassis are bypassed from the vacuum interlock system. Shortening plugs were installed to enable the power supplies to turn on. This will need to be removed before pump down. WP will be left open.

The fast shutter chassis in ISC-R3 is powered on but the enable HV switch needs to be toggled up. See attached picture.

Fil, Dave:

Fil tested the corner station ITMY, ITMX HWWDs by disconnecting one of the satellite amp input connectors for a few seconds on each. The HWWDs went into LED-low-current mode (8) as expected.

We performed this test because over the past week ITMY and ETMX HWWDs have been very quiet, whereas ITMX and ETMY remain noisy. I cannot find any correlation in the main mass top drives signals and these quiet times.

At Jims recommendation, I put the corner station ISIs into damped around 17:45 UTC. HAMs 2, 3, 4, and BSCs 1, 2, 3.

Fil, Camilla WP11987

Fil labeled and then we removed the AS Air and OMC Trans Cameras form HAM6 +X Door. They are being stored on the metal racks in the SQZ bay. Plastic guillotines were inserted before removal and yellow VP covers install. 

I have investigated the gradual increase of the BNS range from ~140 Mpc just after relocking, to ~160 Mpc a few hours after the relock by comparing the coherence between the CAL_DELTAL_EXTERNAL_DQ channel and the SUS, ASC and LSC channels to look for repeating patterns.

I have found that the LSC_SRCL_OUT_DQ channel shows a systematic decrease in coherence in the 20-50 Hz band from just after the relock to when the range has stabilized at ~160 Mpc. This is mirrored by an increase of the BNS-range count in the OAF_RANGE_BAND_3 in the hours just after relocking.

The attached plots show the coherence difference between a time at which the BNS range was at 140 Mpc, in red, and the time at which the BNS range has stabilized at 160 Mpc, in blue, for the four relocks on the 7th of July 2024. I also attached time series plots of the BLRMs for the same time period.

FAMIS 25999

This CPS Spectra was ran after the vent on 2024-07-18.

 

Thu Jul 18 08:04:50 2024 INFO: Fill completed in 4min 47secs

Jordan confirmed a good fill curbside.

TITLE: 07/18 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 6mph Gusts, 4mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.09 μm/s
QUICK SUMMARY:

IFO is in MAINTENANCE for VENTING

Getting ready for an 8:30 meeting detailing plans for the vent this week and beyond.

Other:

  *H1:PEM-CS_DUST_PSL102     WARNING: dust counts did not change, please investigate

Late entry from yesterday (7-16): The Kobelco (corner station purge air supply) was switched on at 4 pm. It needs to run at least 12 hrs before vent

Today's activities:
- The purge air dew point was measured: Right tower (11 am) -42.1 deg C; left tower (11 am) -43.4 deg C; the dew point at the purge port before venting (4:10 pm) -42.2 deg C
- Particle counts of the purge air before venting (4 pm; 3 l/min flow rate): 0 pcs. of 5 um or larger particles
- The following GVs were closed: GV1, GV2, RV-1, RV-2, FCV-1, FCV-2, FCV-3, FCV-4, and GV5 soft closed (see explanation below)
- All the adjacent Ion pumps (IP1, IP2, IP3, IP4, IP14) were valved out
- The OMC RGA was valved out, and now is being pumped by an aux cart
- The Y-manifold Turbo was switched on and valved in, in order to hold the pressure between GV1 and GV5
- The vent started at 16:15, and lasted until 19:30. This means an overall ~3.9 Torr/min pressure rise, which is a nice slow vent. We hit some ~8 Torr overpressure, and then blew the volume down

The reason behind the soft close of GV5: because CP1 is most likely saturated, or at least only has some reduced pumping performance, after closing GV1 and GV2, the pressure of the Y-arm started to rise (notice, that after the close of these 2 GVs, the X-arm CPs were not able to aid the Y-arm CPs). Therefore, the pressure in the Y-manifold started to drop, and the pressure at CP1 (PT-114, PT124) started to raise: this phenomenon would have gone until equilibrium. To avoid the pressure rise of the Y-arm, we soft-closed GV5, and valved in the Y-manifold turbo. This helped, as the pressures are stabilizing now at all areas.
This also shows now undeniably, that the pumping performance of CP1 is seriously reduced, and definitely needs regeneration. And, this also explains the relatively high pressures at LHO's corner (notice, that before the vent it was in the low E-8s, while at LLO it is in the mid-low E-9s).
Tomorrow, some graphs will be added as a comment in this topic.

The pressures:
- Corner: atmosphere
- Y-manifold: 2.9E-8 Torr
- CP1: 4E-9 Torr
- CP2: 5.4E-9

TITLE: 07/17 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 17mph Gusts, 13mph 5min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.08 μm/s
QUICK SUMMARY:

IFO is DOWN and in CORRECTIVE MAINTENANCE - VENTING

With maximum sarcasm, I report that it's been a slow day. Here's a rough rundown:

• Systems meeting for the sole purpose of understanding, planning, drafting, re-drafting and commencing the impromptu LHO Vent in order to deal with the OFI issues.
• HAM 5 and 6 HEPI locked (yesterday), ISIs set to isolated
• Cleanrooms cleaning
• Facilities movement of forklifts
• Search teams for long lost parts (or procurement after loss of patience/hope)
• A team of Jeff and Operators took reference TFs of all soon-to-be vented suspensions (SR3. SRM, OFI, SM6, OMC, OM1, OM2, OM3, SR2) . alog 79189, alog 79188, alog 79198, alog 79202
• Vacuum team in and out of LVEA
  • Checking pressures
  • Closing gate valves
  • Checking Viewports
• Comissioners taking pre-vent alignment checks alog 79193
• High voltage turned off alog 79196
• Laser Safe (now with more safety!) for vent
• Other tasks

The vent plan can be found at E2400260

Other:

EY Intelli-site network down (Fil contacting contractors)

As part of the TF A-Team, SR2 and SR3 TFs can be found here under today's date - 07-17-2024

SR2:

/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SR2/SAGM1/Data

SRM:

/ligo/svncommon/SusSVN/sus/trunk/HSTS/H1/SRM/SAGM1/Data

PDFs to be posted, edited, commented in soon.

SUMMARY:  Transfer Functions COMPLETED for ZM6, OM1, & OM2.  Leaving in DAMPED guardian state for vent.  Will post matlab plots in a comment to this alog later.

Joined team of others (Ibrahim, Jeff, Rahul, RyanC) in getting SUSpension transfer functions in preparation for upcoming vent.  We split up the work amongst us.  I took on ZM6, OM1 and OM2. 

7/18/24 Update NOTE:  OM3 measured by Ryan C, OMC measured by Rahul.  Their results are posted in a comments below!

Instructions for this work is at:  https://awiki.ligo-wa.caltech.edu/wiki/Suspensions/OpsManual/TFs/DTT

For TODAY, this is what I did:

• Run the Transfer Function measurements (and saved the .xml files)
• Exported the data (& saved as .txt files)
• And Added + Committed these new files to the SVN

Here are the locations of the files noted above:

• ZM6:  /ligo/svncommon/SusSVN/sus/trunk/HXDS/H1/ZM6/SAGM1/Data
  • FILES:  2024-07-17_2100_H1SUSZM6_M1_WhiteNoise_[L, P, Y]_0p02to50Hz.xml
• OM1:  /ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/OM1/SAGM1/Data
  • FILES:  2022-10-07_1800_H1SUSOM1_M1_WhiteNoise_[L, P, Y]_0p02to50Hz.xml
• OM2:  /ligo/svncommon/SusSVN/sus/trunk/HXDS/H1/OM2/SAGM1/Data    (not HTTS !!  Although there is another OM2 folder under HTTS.)
  • FILES:  2024-07-17_1900_H1SUSOM2_M1_WhiteNoise_[L, P, Y]_0p02to50Hz.xml

Will leave all of these SUSpensions in their DAMPING  guardian state (vs ALIGNED).

Travis requested that the cell phone alarms for BSC2 vacuum gauge be turned off for the duration of the vent. I have removed the PT120 pressure and error channels from the alarms system and restarted the systemd alarms.service on cdslogin.

Channels removed are:

H0:VAC-LY_Y1_PT120B_PRESS_TORR

H0:VAC-LY_Y1_PT120B_PRESS_TORR_ERROR

The seismic state of HAM5 during this measurement was, ISI_DAMPED_HEPI_OFFLINE and the HEPI was locked yesterday. I put SR3 to DAMPED, made sure the damping outputs were off and the TEST outputs were on. Overall it looks fairly close to the model.

On Roll I saw an extra peak around ~1.04 Hz, and Verticle around ~1.5 Hz (cross coupling from yaw?).

The templates are saved at /ligo/svncommon/SusSVN/sus/trunk/HLTS/H1/SR3/SAGM1/Data

Daniel, Sheila

We turned off the 9 Mhz, 45 MHz, and 117 MHz sidebands in order to do an OMC loss measurement.  We used a single bounce beam off of ITMX, with 10W input from the PSL. We spent some time trying to improve the alignment before making OMC scans. 

locked: 1370711576  (OMC REFL avg 3.51mW, OMC DCPD sum 15.23mA)

unlocked: 1370711782 (OMC REFL avg 24.73 mW, OMC DCPD sum 0.078 mA)

OMC scan start: 1370712036 duration 100 seconds (2nd order modes are roughly 8% of the 00 mode).

shutter blocked: 1370712337 (OMC REFL avg -0.030 DCPD SUM 8e-4 mA). 

Jennie Wright plans to analyze this data to estimate OMC losses.