Initial HAM6 Inspection: New discoloration on Fast Shutter

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.

Fri CP1 Fill

Fri Jul 19 08:04:09 2024 INFO: Fill completed in 4min 6secs

Gerardo confirmed a good fill curbside.

Friday Ops Day Shift Start

TITLE: 07/19 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 8mph Gusts, 5mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.11 μm/s
QUICK SUMMARY:

IFO currently DOWN for maintenace.
LVEA is currently LASER SAFE
Temps in the LVEA have come back down from their peak yesterday.

Expected work today (according to DCC Doc E2400260) :

H6 - Initial inspection of OM1, Refl Beam dump, cables, PDs, beam dumps, etc
H5 - Lock ISI
H5 - Remove OFI Black glass panel shroud pieces from at least +X side and roof.  TAKE CARE TO INVESTIGATE any clipping or anything out of nominal.
Remove HAM6 -X DOOR
H6 - Lock ISI
Pull CC wafers reachable in both chambers
H5 - Initial inspection of OFI and SRM optic surfaces, cables, beam dumps, etc
FTIR sample XX areas on table and around any damage areas (5 sample vials).
H5 - Transition to Laser Haz
Setup AUX laser systems, prioritize HAM5 alignment laser

 

Dominant Axes During EQ Lockloss

Edit : Neil knows how to make links, now. Tony and Camilla were instrumental in this revelation.

This is an update to my previous post (Neil’s previous post on this topic) about looking for possible explinations why similar seismic wave velocities on-site may or may not knock us out of lock.

The same channels are used in addition to:

SEI- * ARM_GND_BLRMS_30M_100M
SEI- * ARM_GND_BLRMS_100M_300M
Where * is C, D, X, or Y.

I have looked at all earthquake events in O4b, and only ones which knocked us out of lock. This is to simplify the pattern search, for now. Here are the results.

Total events : 29

Events with ISI y-motion dominant : 11 (30-100 Hz) : 8 (100-300 Hz)
Events with ISI x-motion dominant : 3 (30-100 Hz) : 0 (100-300 Hz)
Events with ISI z-motion dominant : 9 (30-100 Hz) : 19 (100-300 Hz)

Events with ISI xy-motion dominant : 1 : 0 (Both axes are similar in amplitude.)
Events with ISI yz-motion dominant : 0 : 1
Events with ISI xz-motion dominant : 0 : 1

Events with IS xyz-motion dominant : 5 : 0

Total SEI- * ARM recorded events : 8
CARM dominant events : 7 : 8
C/XARM dominant events : 1 : 0

Conclusion is that in the 30-100 Hz band, it is equally likely to have either z- or y-axis motion be dominant. In the 100-300 Hz band, the ratio is about 1:2 for z and y motion being dominant during lockloss.

Clearly, common modes are a common (^_^) cause of lockloss.

Note that velocity amplitudes should be explored more.

7-18 vent vacuum diary

Today's activities:
- The purge air dew point was measured at the purge port: (9:15 am) -42.5 deg C
- The relay tube was vented with Nitrogen, and was taken off: at the HAM5 side, the dog leg stayed, and at HAM7, one bellows was left there
- The HAM5/HAM6 annulus system was vented with Nitrogen, the AIPs have been turned off
- HAM5+X, HAM5-X, HAM6+X doors have been removed. Both HAM5 doors' inner O-ring are needed to be replaced, as they are damaged and worn out
- IP19 was valved out at the top of HAM7
- HAM7 was vented, but all doors are staying in place for now
- The pressures outside the corner have been stabilized now, and consistently dropping

The pressures:
- Corner, HAM7: atmosphere
- Y-manifold: 3E-8 Torr
- CP1: 3.9E-9 Torr
- CP2: 5.3E-9 Torr

OFI shroud partially removed

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.

HAM8 H1 GS13 troubleshooting, bad shield connection edition

On a Tuesday a couple weeks back I went to HAM8 and looked at connections between the shield pins for all of the single axis seismometers on HAM8, both at the rack and at the feedthru on the chamber. For the H1 seismometer I found that pin 9 (labeled as GS13-2 Sig+ on D1002706) is grounded to pin 5, which is the shield, this would explain why the sensor has a gain of 1/2 compared to the other seismometers. None of the other GS13s show this shield connection to signal. However, 2 of the L4C pairs have multiple wires connected to the shield, I haven't run down what they are yet. All of the wires that are connected to shield are connected at both the rack and the flange, so the issue is somewhere in vacuum. Can't really tell more at this point without opening the chamber. I plan to check HAM7 at some point, but that is a borrow from 3ifo.

Mitch and I did some tests on what spare A+ cables we could find in the staging building, 2 D1000227 pigtails and 2 220(?) 25pin extensions. We couldn't find or cause any connections between the shields and signal wires, but it wasn't an exhaustive test. I'm also huddling some GS13s on the table, I will try to see if there are any wire-shield connections with the cables that are plugged into those sensors.

OPS Day Shift Summary

TITLE: 07/18 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY:

IFO is in CORRECTIVE MAINTENANCE for VENTING

Productive day where we found the culprit (yet to be seen if there are more) to our OFI issues in the form of a burn on the KTP Optic of the OFI (alog 79223). After this point, there were impromptu meetings discussing how to proceed. A slight shift of priorities was announced and the check-list is as follows (E2400260):

WED JULY 17

1. ✅ Check that after HEPI locking SQZ and single bounce beams both go to AS_C, find SRM and SR2 slider values to simulate alignments from early April and from June.
2. ✅ Check ITM OPLEVs
3. ✅ Close GV1,2sheila.d, FC tube GVs
4. ✅ Vent Corner, HI Volts on/off, see their M-doc. Full laser Safe transition. 

THUR JULY 18

1. ✅ Vent and Remove Relay tube
2. ✅ Remove Cameras from HAM6 door (alog 79213)
3. ✅ Open HAM5 via  +X DOOR
4. ✅ Open HAM6 via  +X DOOR
5. ✅ Vent HAM7
6. ✅ HI VOLT BYPASS back on (alog 79222)
7. ✅ Remove HAM5 -X DOOR
8. H6 - Initial inspection of OM1, Refl Beam dump, cables, PDs, beam dumps, etc
9. H5 - Lock ISI
10. H5 - Remove OFI Black glass panel shroud pieces from at least +X side and roof.  TAKE CARE TO INVESTIGATE any clipping or anything out of nominal.

FRI JULY 19

1. Remove HAM6 -X DOOR
2. H6 - Lock ISI
3. Pull CC wafers reachable in both chambers
4. H5 - Initial inspection of OFI and SRM optic surfaces, cables, beam dumps, etc
5. FTIR sample XX areas on table and around any damage areas (5 sample vials).
6. H5 - Transition to Laser Haz
7. Setup AUX laser systems, prioritize HAM5 alignment laser 
8. Using SQZ beam delivered from HAM7, make OFI Measurements in-situ:
   1. Measure loss after each component inc. SRM with power meter. 
9. Transition back to Safe when done.

Aditionally, all TFs for pe-vent suspensions have submitted ALL_TF and comparison TF reports as comments to their initial alogs: alog 79189, alog 79188, alog 79198, alog 79202

These plans are of course tentative and depend on ongoing decisions in this living (and breathing) document. Well done to the quick, efficient and safe vent crew!

THIS JUST IN: Approximately 3s before hitting enter, the vent crew came back with more pictures of backsplashed debris from the two burn spots in the OFI. Stay tuned for more (alogs).

LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
14:48	FAC	Karen, Kim	LVEA	N	Technical Cleaning	15:48
15:53	EE	Fil, Camilla	LVEA	N	Pulling off HAM6 Cameras	16:53
16:10	FAC	Chris, Eric	HAM6	N	Breaking torque on HAM6 Door Bolts	19:20
16:12	FAC	McCarthy	HAM6	N	Ensuring Safety during door work	18:12
16:14	FAC	Bubba G	EX & EY	N	Resuppling First Aid Kits	17:26
16:16	VAC	Jordan, Tyler	HAM6	N	HAM6 Door Bolt Torque breaking	19:38
16:18	VAC	Travis, Gerardo	LVEA	N	Relay tube VAC work & HAM6 Door crew work. Travis out 19:15UTC	19:31
16:31	FAC	Tyler	FCES	N	Camera Acquisition	16:52
16:33	VAC	Jason	LVEA	N	Aux lasers for LVEA vent team	16:42
16:44	EE	Keita	LVEA	N	Fil BNC Cable HAM6	17:10
16:57	FAC	Kim, Karen	LVEA	N	Technical Cleaning	17:57
16:58	FAC	Fil	LVEA	N	Interlock	17:58
17:11	SQZ	Keita, Jennie	Optics lab	Local	Work on HAM5/6 laser	19:38
17:23	SQZ	Camilla	Optics lab	Local	Check if team has all the parts they need	18:40
17:45	CAL	Tony	PCAL lab	LOCAL	Gather stuff	18:03
18:41	SQZ	TJ	Optics Lab	Local	Part search Part 2	19:08
18:41	FAC	Richard	LVEA	N	Supervision	19:01
18:42	PCAL	Rick, Guest	LVEA	N	Walking Tour	19:20
19:05		Betsy	LVEA	N	Check on crew	19:25
19:39	EE	Fil	CER	N	ISI WD Cable Reset	20:28
19:43	PCAL	Rick, Dripta, Emmanuel, Shingo, Dan	EY	YES	PCAL Measurements	21:54
20:23	FAC	Tyler	LVEA	N	HAM5 -X Door Removal Prep	21:51
20:28	VAC	Chris, Jordan, Travis	LVEA	N	HAM5 -X Door Removal	21:51
21:32	SUS	Mitchell, Betsy, TJ, Sheila	LVEA	N	HAM5 Door + OFI	23:32
22:26		Oli	LVEA	N	Parts dropoff	22:30
22:42		Ibrahim	LVEA	N	Sensor calibration	22:45
23:28	PCAL	Tony, Emmanuel	PCAL Lab	Local	LHO PS4 PS5 Measurement	00:28

Magnet-standoff assembly bonded to SRM-07 (HSTS spare optic)

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.

Quick inspection of the first OFI comonents visible as the door came off

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

 

TBC...

High Voltage for HAM7 and HAM6 Back On

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.

HWWD test, ITMY and ETMX have gone very quiet in past week

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.

 

CS SEI to damped

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

Pre-Vent SRM and SR2 Transfer Functions

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.

ZM6, OM1, OM2 (+OM3 by RyanC, +OMC by Rahul) Transfer Functions Are COMPLETED (In Prep For Vent)

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).

SR3 transfer functions

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

OMC Scan with PSL beam

Jennie W, Sheila,

 

We turned off the 9 and 45 MHZ sideband EOMs and unplugged the 118 MHz modulation at the PSL racks. See this alog for how to do this.

 

We locked the IMC and mis-aligned ITMX.

 

DC centering loops 3 and 4 were turned on.

 

Sheila took the OMC lock guardian to PREP OMC scan and turned on the OMC ASC.

We waited for this to converge then turned it off.

 

We turned input power up to 10W from 2W and then locked the OMC in length manually by using the PZT offset slider to search for a high peak ~ 15mA.

After finding it we turned on the locking with a gain of 24 and the boost and int filters on (we checked the settings we needed in the guardian as we couldn't get the OMC guardian to lock it for us).

 

Then we turned off the OMC ASC.

 

We tuned up the OM3 and OMC alignment slightly to maximise the power on OMC-DCPD_SUM_OUTPUT and minimise it on OMC-REFL_A_LF_OUT16.

OM3 was moved down in yaw only from -108 to -117 and OMC was moved down in yaw from 210.5 to 195.5 and down in pitch from 350.4 to 340.4. The final values for the sliders are here.

 

Quiet time locked after aligning 16:21:03 UTC - 16:24:13 UTC

OMC-REFL_A_LF_OUT16 = 0.652644 mW

OMC-DCPD_SUM_OUTPUT = 15.6162 mA

 

Quiet time unlocked 16:25:31 UTC -16:27:35 UTC

OMC-REFL_A_LF_OUT16 = 30.106 mW

OMC-DCPD_SUM_OUTPUT = 0.000456763 mA

 

We took the IMC guardian offline and shuttered the green light going into both arms at the ISC tables, and with ISC_LOCK guardian in idle so it wouldn't keep trying to relock IMC.

Quiet time dark measurement 16:43:38 - 14:46:19 UTC

OMC-REFL_A_LF_OUT16 = -0.0132979 mW

OMC-DCPD_SUM_OUTPUT = -0.00106226 mA

 

The scan template is saved as /ligo/home/jennifer.wright/Documents/OMC_scan/2024_04_16_OMC_scan.xml

With the references for the time series of the three pertinent channels as:

Ref 0 OMC-DCPD_SUM_OUT_DQ

Ref 1 OMC-PZT2_EXC

Ref 2 OMC-PZT2_MON_DC_OUT_DQ

 

OMC loss measurement

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.