aLIGO LHO Logbook

H1 ISC - EOM Heliax Cables Pulled and Landed at PSL-R2

marc.pirello@ligo.org — Thu, 22 Jan 2026 09:31:51 -0800

Author: marc.pirello@ligo.org

Report ID: 88842

Per WP12989 we completed the EOM cable install from PLS-R2 to the HAM-1 feedthrough. The old EOM cables from the PSL were disconnected at the patch panel, and the RF Combiner was powered down. RF Cables were landed at the patch panel from left to right, 24MHz, 118MHz, 45MHz, 9MHz, with 2 empty spigots on the right hand side of the panel located at U2 in the rack near the floor. We will shoot these with the TDR to once everything is installed to get total electrical length for calibration.

M. Pirello, F. Clara

ISC

H1 General - Comment to OPS Thursday day shift start

ryan.crouch@ligo.org — Thu, 22 Jan 2026 08:26:28 -0800

Author: ryan.crouch@ligo.org

Report ID: 88841

There is a planned DAQ restart today as well.

H1 General - OPS Thursday day shift start

ryan.crouch@ligo.org — Thu, 22 Jan 2026 07:25:25 -0800

Author: ryan.crouch@ligo.org

Report ID: 88840

TITLE: 01/22 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 5mph Gusts, 3mph 3min avg
Primary useism: 0.03 μm/s
Secondary useism: 0.17 μm/s
QUICK SUMMARY:

HAM1 work today, EOM installation and JAC mode matching
A 4.7 from Wyoming rolled through ~3 hours ago
The LVEA remains in LASER HAZARD

H1 General - OPS Wednesday DAY shift summary

ryan.crouch@ligo.org — Wed, 21 Jan 2026 16:30:57 -0800

Author: ryan.crouch@ligo.org

Report ID: 88835

TITLE: 01/22 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: OPO and JAC work continued in HAMs 1 & 7 in LASER HAZARD.
LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
22:49	SAF	LVEA IS LASER HAZARD	LVEA	YES	LVEA IS LASER HAZARD \u0d26\u0d4d\u0d26\u0d3f(\u239a_\u239a)	16:49
15:31	FAC	Randy	EndY	N	Bring a forkflit down to the CS/High bay	17:24
15:53	FAC	Kim, Nellie	LVEA	Y	Tech clean	17:53
17:01	SUS	RyanC	CR	N	ZM4 Transfer function	17:24
17:07	JAC	Matt, Sophie	PREP lab	N	JOTE work	19:36
17:10	SQZ	Sheila, RyanS, Kar Meng	HAM7	Y	Chamber work, Kar Meng in at 1900	21:02
17:17	PEM	Robert	LVEA HAM4	Y	Laser vibro, in and out	18:17
17:57	ISC	Jason	LVEA	Y	HAM1 work	20:52
18:07	ISC	Rahul	LVEA	Y	HAM1	20:05
18:20	FAC	Eric	HAM Shaq	N	Changing filters	18:51
18:27	ISC	Jennie	LVEA	Y	HAM1 work	19:14
19:22	ISC	Jennie, Keita	LVEA	Y	HAM1 work	20:52
19:33	VAC	Travis	Optics lab	N	Put away part	19:43
19:36	FAC	Kim	H2	N	Tech clean	19:54
19:53	CDS	Oli	LVEA, CER	Y	Take pictures of computer racks	20:05
21:21	VAC	Travis	MidX	N	Look for VAC equipment	21:39
21:21	VAC	Jordan	FCES	N	Look for VAC equipment	21:49
21:34	SUS	Rahul	Optics lab	LOCAL	Work on EOM	23:03
22:02	EE	Marc, Fil	LVEA	Y	Run cable for EOM from HAM1 to PSL racks	Ongoing
22:33	VAC	Gerardo	VAC prep lab to LVEA	Y	Bring over glass piece to HAM1	23:38
23:38	VAC	Gerardo	VAP prep lab	N	Assembly work	00:19

19:24 OPO WD trip

H1 PSL - PSL 10-Day Trends

ryan.short@ligo.org — Wed, 21 Jan 2026 16:02:26 -0800

Author: ryan.short@ligo.org

Report ID: 88838

FAMIS 31121

Things are looking very stable over the past week; makes sense since very little has been asked of the PSL recently. The PMC and RefCav could still use an alignment touch-up, which I'll get to hopefully this week.

Images attached to this report

H1 SUS - Renamed SR3 OPLEV Whitening to AA cable

oli.patane@ligo.org — Wed, 21 Jan 2026 15:26:31 -0800

Author: oli.patane@ligo.org

Report ID: 88837

Jeff, Oli

We decided to rename the SR3 OPLEV Whitening to AA chassis cable from SUS_SR3-168 to SUS_OPLEV_SR3_AA. We decided to do this for a couple reasons: SUS_SR3-168 is not a very helpful name, it matches better with the other OPLEVs' cables, and anyway we had already been calling that cable SUS_OPLEV_SR3_AA in our wiring diagrams for a while.
We relabeled both sides of the cable.

H1 SUS - SUS Model Updates: h1susauxb2h34

oli.patane@ligo.org — Wed, 21 Jan 2026 14:47:22 -0800

Author: oli.patane@ligo.org

Report ID: 88820

Jeff, Oli

We made several updates to multiple SUS simulink models as a continuation of our work converting SUSB123 and SUSH34 into SUSB13 and SUSB2H34 (88765). Our changes were based on our updated G2301306-v10_PARTII - for the conversion from SUSH34 into SUSB13 for SUSAUXB2H34, we referenced slides 25 and 26. These changes were svn'd as r34398 and were installed and started last week (88781).

These are the changes we had to made for h1susauxb2h34 (previously called h1susauxh34):

CDS Parameter Block:
- Changed hostname from h1susauxh34 to h1susauxb2h34
- Removed specific_cpu

Input (before, after):
- Added ADC6 and ADC7
- Added BS block (taken from susauxb123)
- Connected ADC6 and ADC7 to BS block

BS Block (after):
- Connected up ADCs according to slide 26

CDS

Images attached to this report

Non-image files attached to this report

G2301306-v10_PARTII_SUSB2H34_SUSB13.pdf

H1 SUS - SUS Model Updates: h1sussr2

oli.patane@ligo.org — Wed, 21 Jan 2026 14:47:19 -0800

Author: oli.patane@ligo.org

Report ID: 88817

Jeff, Oli

We made several updates to multiple SUS simulink models as a continuation of our work converting SUSB123 and SUSH34 into SUSB13 and SUSB2H34 (88765). Our changes were based on our updated G2301306-v10_PARTII - for the conversion from SUSH34 into SUSB2H34 for SR2, we referenced slides 8, 10, 14, 15, 20, and 21. These changes were svn'd as r34385 and were installed and started last week (88781).

These are the changes we had to make for h1sussr2:

CDS Parameter Block:
- Changed hostname from h1sush34 to h1susb2h34
- Removed specific_cpu

Input (before, after):
- Changed ADC to OSEM channels for M1 RT and SD

Output (before, after):
- Changed DACs from multiple 18 and 20 bit DACs to one 20 bit DAC and one 28 bit DAC
- Lined up outputs to their corresponding DAC channels

CDS

Images attached to this report

Non-image files attached to this report

G2301306-v10_PARTII_SUSB2H34_SUSB13.pdf

H1 SUS - SUS Model Updates: h1suspr2

oli.patane@ligo.org — Wed, 21 Jan 2026 14:47:15 -0800

Author: oli.patane@ligo.org

Report ID: 88816

Jeff, Oli

We made several updates to multiple SUS simulink models as a continuation of our work converting SUSB123 and SUSH34 into SUSB13 and SUSB2H34 (88765). Our changes were based on our updated G2301306-v10_PARTII - for the conversion from SUSH34 into SUSB2H34 for PR2, we referenced slides 8, 10, 14, 15, 20, and 21. These changes were svn'd as r34387 and were installed and started last week (88781).

These are the changes we had to make for h1suspr2:

CDS Parameter Block:
- Changed hostname from h1sush34 to h1susb2h34
- Removed specific_cpu

Output (before, after):
- Changed DACs from multiple 18 bit DACs to one 20 bit DAC and one 28 bit DAC
- Lined up outputs to their corresponding DAC channels

CDS

Images attached to this report

Non-image files attached to this report

G2301306-v10_PARTII_SUSB2H34_SUSB13.pdf

H1 SUS - SUS Model Updates: h1susmc2

oli.patane@ligo.org — Wed, 21 Jan 2026 14:47:05 -0800

Author: oli.patane@ligo.org

Report ID: 88815

Jeff, Oli

We made several updates to multiple SUS simulink models as a continuation of our work converting SUSB123 and SUSH34 into SUSB13 and SUSB2H34 (88765). Our changes were based on our updated G2301306-v10_PARTII - for the conversion from SUSH34 into SUSB2H34 for MC2, we referenced slides 8, 10, 14, 15, 20, and 21. These changes were svn'd as r34384 and were installed and started last week (88781).

These are the changes we had to make for h1susmc2:

CDS Parameter Block:
- Changed hostname from h1sush34 to h1susb2h34
- Removed specific_cpu

Input (before, after):
- Removed ADC1 since now all OSEM channels are on ADC0
- Redid ADC to OSEM configuration
- Added BS BIO channels for each BS stage (coming in from BS) to SHMEM since the BS BIO is now on the MC2 model

Output (before, after):
- Changed DACs from multiple 18 bit DACs to one 28 bit DAC
- Lined up outputs to their corresponding DAC channels
- Added BS BIO channels for each BS stage (going out to BS) to SHMEM
- Changed ADC channels going to SR3 oplev in PCIE

Binary I/O (before, after):
- Added BS to BIO ENCODE and DECODE blocks
- Added BIO cards for BS
- Added inputs and outputs to BIO blocks for BS

CDS

Images attached to this report

Non-image files attached to this report

G2301306-v10_PARTII_SUSB2H34_SUSB13.pdf

H1 SUS - SUS Model Updates: h1susbs

oli.patane@ligo.org — Wed, 21 Jan 2026 14:46:37 -0800

Author: oli.patane@ligo.org

Report ID: 88814

Jeff, Oli

We made several updates to multiple SUS simulink models as a continuation of our work converting SUSB123 and SUSH34 into SUSB13 and SUSB2H34 (88765). Our changes were based on our updated G2301306-v10_PARTII - for the movement of the BS from SUSB123 to SUSB2H34, we referenced slides 5, 10, 12, 15, 18, and 21. These changes were svn'd as r34436 and were installed and started last week (88781).

These are the changes we had to make for h1susbs:

CDS Parameter Block:
- Changed dcuid
- Changed hostname from h1susb123 to h1susb2h34
- Removed specific_cpu

Input (before, after):
- Removed ADC1 since now all OSEM channels are on one ADC (called ADC1 in diagrams)
- Redid ADC to OSEM configuration
- Removed ITMX L3 and ITMY L3 channels from SHMEM that came in for ITM L3 BIO
- Added BS BIO channels for each BS stage (coming in from MC2) to SHMEM since the BS BIO is now on the MC2 model
- Redid BIO MON stage inputs into BS block to now read in values from SHMEM
- MCDIO_2_BSM3 is terminated since current BS block doesnt have an M3 BIO

Output (before, after):
- Changed DACs from multiple 20 bit DACs to one 28 bit DAC
- Lined up outputs to their corresponding DAC channels
- Removed ITMX and ITMY L3 BIO channels that went out to ITMX and ITMY from SHMEM
- Added BS BIO channels for each BS stage (going out to MC2) to SHMEM since BS BIO is now on the MC2 model
- Redid BIO CTRL OUT outputs from BS block to now go out to SHMEM channels
- BS M3 has a 0 coming in for now since current BS block doesn't have an M3 BIO

Binary I/O (before, after):
- Removed BIO blocks since BS BIO is now happening in the MC2 model

CDS

Images attached to this report

Non-image files attached to this report

G2301306-v10_PARTII_SUSB2H34_SUSB13.pdf

H1 SUS - SUS Model Updates: h1susauxb13

oli.patane@ligo.org — Wed, 21 Jan 2026 14:46:28 -0800

Author: oli.patane@ligo.org

Report ID: 88819

Jeff, Oli

We made several updates to multiple SUS simulink models as a continuation of our work converting SUSB123 and SUSH34 into SUSB13 and SUSB2H34 (88765). Our changes were based on our updated G2301306-v10_PARTII - for the conversion from SUSB123 into SUSB13 for SUSAUXB13, we referenced slides 23 and 24. These changes were svn'd as r34396 and were installed and started last week (88781).

These are the changes we had to made for h1susauxb13 (previously called h1susauxb123):

CDS Parameter Block:
- Changed hostname from h1susauxb123 to h1susauxb13
- Removed specific_cpu

Input (before, after):
- Removed BS block
- Removed ADC6 and ADC7
- ADC0 flag going into ITMY block is now in ADC5
- ADC7 flag going into ITMY block is now in ADC0

ITMY block (before, after):
- Removed ADC7
- Everything that was previously ADC0 is now in ADC5
- Everything that was previously ADC7 is now in ADC0

CDS

Images attached to this report

Non-image files attached to this report

G2301306-v10_PARTII_SUSB2H34_SUSB13.pdf

H1 SUS - SUS Model Updates: h1susitmpi

oli.patane@ligo.org — Wed, 21 Jan 2026 14:44:44 -0800

Author: oli.patane@ligo.org

Report ID: 88818

Jeff, Oli

We made several updates to multiple SUS simulink models as a continuation of our work converting SUSB123 and SUSH34 into SUSB13 and SUSB2H34 (88765). Our changes were based on our updated G2301306-v10_PARTII - for the conversion from SUSB123 into SUSB13 for the ITM PI's, we referenced slides 5 and 7. These changes were svn'd as r34388 and were installed and started last week (88781).

These are the changes we had to make for h1susitmpi:

CDS Parameter Block:
- Changed hostname from h1susb123 to h1susb13
- Removed specific_cpu

Output (before, after):
- Change 20 bit DAC into a 28 bit DAC
- Wire up ITMX and ITMY PI OSEM outputs to their corresponding DAC channels

CDS

Images attached to this report

Non-image files attached to this report

G2301306-v10_PARTII_SUSB2H34_SUSB13.pdf

H1 SUS - SUS Model Updates: h1susitmy

oli.patane@ligo.org — Wed, 21 Jan 2026 14:44:23 -0800

Author: oli.patane@ligo.org

Report ID: 88813

Jeff, Oli

We made several updates to multiple SUS simulink models as a continuation of our work converting SUSB123 and SUSH34 into SUSB13 and SUSB2H34 (88765). Our changes were based on our updated G2301306-v10_PARTII - for the conversion from SUSB123 into SUSB13 for ITMY, we referenced slides 5, 7, 12, 13, 18, and 19. These changes were svn'd as r34388 and were installed and started last week (88781).

These are the changes we had to make for h1susitmy:

CDS Parameter Block:
- Changed hostname from h1susb123 to h1susb13
- Removed specific_cpu

Input (before, after):
- Removed ADC1 since now all OSEM channels are on ADC0
- Redid ADC to OSEM configuration
- Removed ITMY L3 BIO channel (coming from BS) from SHMEM
- Added ITMX L3 BIO channel (coming in from ITMX L3) to SHMEM since the L3 BIO is now on the ITMY model

Output (before, after):
- Changed DACs from several 20 bit DACs to two 28 bit DACs
- Lined up outputs to their corresponding DAC channels
- Lined up ESD bias and ESD sum outputs to their corresponding DAC channels
- Removed ITMY L3 BIO channel (that went out to BS) from SHMEM
- Added ITMX L3 BIO channel (that goes out to ITMX) to SHMEM since L3 BIO is now on the ITMY model

Binary I/O (before, after):
- Added ITMX L3 and ITMY L3 BIO inputs and routing into the ITMY_BIO_ENCODE block
- Added the ITMX L3 and ITMY L3 BIO out cards
- Added ITMX L3 and ITMY L3 BIO routing into the ITMY_BIO_DECODE block and outputs
- Removed the HWWD_CONTROL input from the ITMY_BIO_ENCODE block and removed the wire going into it from the ITMY_HWWD_BIN_OUT block since there is no physical cable there

CDS

Images attached to this report

Non-image files attached to this report

G2301306-v10_PARTII_SUSB2H34_SUSB13.pdf

H1 SUS - SUS Model Updates: h1susitmx

oli.patane@ligo.org — Wed, 21 Jan 2026 14:44:09 -0800

Author: oli.patane@ligo.org

Report ID: 88812

Jeff, Oli

We made several updates to multiple SUS simulink models as a continuation of our work converting SUSB123 and SUSH34 into SUSB13 and SUSB2H34 (88765). Our changes were based on our updated G2301306-v10_PARTII - for the conversion from SUSB123 into SUSB13 for ITMX, we referenced slides 5, 7, 12, 13, 18, and 19. These changes were svn'd as r34388 and were installed and started last week (88781).

These are the changes we had to make for h1susitmx:

CDS Parameter Block:
- Changed hostname from h1susb123 to h1susb13
- Removed specific_cpu

Input (before, after):
- Removed ADC1 since now all OSEM channels are on one ADC (called ADC1 in diagrams)
- Redid ADC to OSEM configuration
- Changed name of SHMEM channel that comes in for ITMX L3 BIO
- Previously was H1:SUS-ITMX_BIO_L3_MON_SHMEM, now is H1:SUSITMY_2_ITMX_L3_BIOMON_SHMEM

Output (before, after):
- Changed DACs from several 20 bit DACs to two 28 bit DACs
- Lined up outputs to their corresponding DAC channels
- Lined up ESD bias and ESD sum outputs to their corresponding DAC channels
- Changed name of SHMEM channel that goes out for ITMX L3 BIO
- Previously was H1:SUS-ITMX_BIO_L3_CTRL_SHMEM, now is H1:SUSITMY_2_ITMX_L3_BIOCTRL_SHMEM

CDS

Images attached to this report

Non-image files attached to this report

G2301306-v10_PARTII_SUSB2H34_SUSB13.pdf

H1 SQZ - HAM7 progress update

karmeng.kwan@ligo.org — Wed, 21 Jan 2026 14:34:13 -0800

Author: karmeng.kwan@ligo.org

Report ID: 88836

[Sheila, Ryan, Karmeng]

We have returned ZM2 to the original position at the beginning of O4, we alleviated some of the saturation but the ZM3 iris still require adjustment.

Power budget looks good so far. With 0.77mW exiting the OPO and reaches AM3 at the same power. We observed 0.75mW of OPO trans and 18.1mW of OPO refl on SQZT7 periscope.

SYS

H1 IOO - HAM1 update - JAC damper

rahul.kumar@ligo.org — Wed, 21 Jan 2026 13:04:18 -0800

Author: rahul.kumar@ligo.org

Report ID: 88834

Jason. JennieW, Rahul

This morning we added the damper parts to the JAC in HAM1 chamber - see picture attached. The cables were re-routed slightly so that they don't interfere with the damper.

I have finger tightened the screws of the damper for now - since no torque spec was provided and we were worried that tightening them too much might affect its position/angle.

IOO

Images attached to this report

H1 SUS - 2nd HXDS received from LLO

ryan.crouch@ligo.org — Wed, 21 Jan 2026 11:44:42 -0800

Author: ryan.crouch@ligo.org

Report ID: 88828

Yesterday I picked up the shipment from LLO contain the 2nd HXDS (first HXDS shipment alog87998) and related ASSEYs and brought it to the Triples lab.

Uwrapping and inspecting was uneventful, the zip ties were intact, the shock pads untripped and the humidity indicator was unchanged in color. The outer (front, back) and inner (front, back) bags were in good condition, unwrapping the suspension I found no play with the blades. All the nuts and dowel pins were tight and well seated, the ICS looks good except for it seems to be missing the HDS Intermediate Mass Fixture (D2000230-V1, s/n 08). The part is scribed as V1, on the dcc there's a V2 with two added 8-32 helicoils taps that, based on D1900352 which uses V2, I should be able to see from the front and I don't, so this is a V1 plate and not an incorrectly scribed V2. I believe these two missing 8-32 holes are where we will attach the BOSEM Mounting plate (D2000257). The first HXDS we received in November had the V2 plate. We may have to do a small rework to update it to V2, or have LLO send the V2 part if possible.

SUS

Images attached to this report

LHO General - FCES air handler

eric.otterman@ligo.org — Wed, 21 Jan 2026 11:03:26 -0800

Author: eric.otterman@ligo.org

Report ID: 88832

The pre-filters were replaced in the FCES air handler.

LHO VE - Wed CP1 fill

david.barker@ligo.org — Wed, 21 Jan 2026 10:16:50 -0800

Author: david.barker@ligo.org

Report ID: 88831

Wed Jan 21 10:08:13 2026 INFO: Fill completed in 8min 10secs

Images attached to this report

H1 ISC - Comment to POP periscope stiffener was installed. B&K for POP as well as JAC input periscope (Rahul, Jim, Keita)

jim.warner@ligo.org — Wed, 21 Jan 2026 10:13:09 -0800

Author: jim.warner@ligo.org

Report ID: 88830

These are the measurements we got with the B&K of the POP periscope before and after adding the stiffener. For the POP periscope, we mounted the accel to the table, right at the foot of the periscope, and did the impacts at the top of the post. The accelerometer was mounted with the sensors Z aligned vertically, the Y axis was roughly parallel to the edge of the ISI, so it was mostly pointing along the IFO X arm. First and second images are impacts in the IFO X and Y dofs, you can pretty clearly see the 70hz post resonance. Third, fourth and fifth images are with the accelerometer in the same spot after adding the stiffener, it seems the mode has successfully been moved much higher to around 170hz. This should allow me to increase the ugf and loop gain quite a bit, to be more like the other ISI. I'll verify with tfs on the ISI after the vent.

Last 3 images are B&K measurements of the JAC periscope, accel for these measurements was mounted on the edge of the table, with x,y,z sensor dofs aligned to the IFO x,y,z dofs. This also looks pretty good, first features are over 200hz.

Attached zip contains the csv data exports of each of the measurements. Names indicate the direction of the hit with the hammer, relative to IFO x,y,z conventions.

Images attached to this report

Non-image files attached to this report

ham1_periscope_b&k_data.zip

H1 SEI - ISI CPS Noise Spectra Check Weekly FAMIS

oli.patane@ligo.org — Wed, 21 Jan 2026 09:59:48 -0800

Author: oli.patane@ligo.org

Report ID: 88829

Closes FAMIS#39334, last checked 88680

The elevated sensors listed are just from HAM1 and HAM7, which is expected
All chambers are looking normal relative to the current state that they are in (locked, vented, etc)

Non-image files attached to this report

CPS_spectra_09:38-01_21_2026.pdf

H1 SUS - Comment to HAM7 - ZM4 physically moved in Yaw

ryan.crouch@ligo.org — Wed, 21 Jan 2026 09:49:27 -0800

Author: ryan.crouch@ligo.org

Report ID: 88827

I ran a quick transfer functions on ZM4, a few things to note. The suspension is in air so I changed the Coil Driver state from 2 to 1 (reverted once I was done) as the wiki suggested, the ISI is also tripped but the damping was engaged on the suspension. We were also slightly shaking due to an 6.1 earthquake from near Japan.

The suspension is looking healthy.

/ligo/svncommon/SusSVN/sus/trunk/HXDS/H1/ZM4/SAGM1/Data/

2026-01-21_1700_H1SUSZM4_M1_WhiteNoise_L_0p01to50Hz.xml
2026-01-21_1700_H1SUSZM4_M1_WhiteNoise_P_0p01to50Hz.xml
2026-01-21_1700_H1SUSZM4_M1_WhiteNoise_Y_0p01to50Hz.xml

SUS

Images attached to this report

H1 General - OPS Wednesday Day shift start

ryan.crouch@ligo.org — Wed, 21 Jan 2026 07:32:44 -0800

Author: ryan.crouch@ligo.org

Report ID: 88826

TITLE: 01/21 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 5mph Gusts, 3mph 3min avg
Primary useism: 0.01 μm/s
Secondary useism: 0.17 μm/s
QUICK SUMMARY:

Some of the tasks on the board today:

More HAM7 work, in laser hazard
HAM1 viewport simulator
Laser vibrometer measurements of MCT baffles

H1 ISC - Comment to POP periscope stiffener was installed. B&K for POP as well as JAC input periscope (Rahul, Jim, Keita)

corey.gray@ligo.org — Wed, 21 Jan 2026 07:29:27 -0800

Author: corey.gray@ligo.org

Report ID: 88825

Tagging EPO for photos.

EPO

H1 SQZ - Comment to HAM7 progress

sheila.dwyer@ligo.org — Tue, 20 Jan 2026 22:28:17 -0800

Author: sheila.dwyer@ligo.org

Report ID: 88824

Some additional information:

In december we checked that the alignment sliders on FC1 had not moved since the observing run. Noting that the red and green co-alignment were off, this morning I trended osems as well and saw that FC1 had a shift of +200urad in pitch at the time of the vent. The ZMs all had similar shifts. When I moved FC1 to make sure the osem values matched the observing run pitch, the beam was then clipped on B:P1. We adjusted B:M1 to clear the VIP, then adjusted B:M4 to recenter the beam on the ZM4 iris. Then Kar Meng adjusted ZM4 alignment to match the irises on SQZT7 in the homodyne path. After this we saw that the beams were still on the QPDs in HAM6, but not well centered. We will have to return to that tomorow.

After that we turned our attention to the co-alignment of the FC green sensing with the squeezed beam. The shift in the FC1 pitch wasn't enough to make a difference in the large misalingment of these two. We became confused for a while looking at the FC green beam in the SK path. The old HAM7 layout shows the SK path on the -X side of the three beams leaving the chamber toward the green periscope, this is correct but the two beams cross as they travel down the periscope so that the FC green refl path is on the -X side by the time it reaches the bottom, and looking at the SQZT7 layout shows the SK path located on the table in the area where the FC green refl path is.

Once we understood this path, we were able to walk H:M1 to coalign red and green right after A:DC2, and using H:M2 to co-align them at the iris after ZM3. Then we adjusted the pointing to the periscope using H:M4.

While we were in laser safe, I unlocked the OPO suspension, since we hope that we are finished with the alignment work on the VIP. This caused enough of a shift that the reflected seed beam was clipping on its way to the diode, perhaps on the lens in HAM7. We moved this beam so that it is still mis centered on the lens but not close to the edge.

H1 ISC - Comment to POP periscope stiffener was installed. B&K for POP as well as JAC input periscope (Rahul, Jim, Keita)

keita.kawabe@ligo.org — Tue, 20 Jan 2026 17:56:27 -0800

Author: keita.kawabe@ligo.org

Report ID: 88823

Unused stiffener parts are in my office for now.

H1 ISC - POP periscope stiffener was installed. B&K for POP as well as JAC input periscope (Rahul, Jim, Keita)

keita.kawabe@ligo.org — Tue, 20 Jan 2026 17:53:53 -0800

Author: keita.kawabe@ligo.org

Report ID: 88822

We have intalled the POP periscope stiffener.

Some dog clamps in the REFL path as well as the cable bracket for PM1 were relocated to accomodate. 1st and 2nd picture are "before" photo. 3rd one is after PM1 cable bracket relocation but before installing the stiffener. There are also three "after" photos showing how things look on the table.

POP beam clearance:

I took the picture of the bottom periscope mirror through dichroic (HR for IR, transmission for green) to see the beam clearance. In the first such photo (POP_beam_clearance.jpg), the camera is close to the center of the dichroic and the short stiffener beam is close to the edge of the optic but not occulting the mirror, so we're OK. Just to make sure that we're absolutely safe, I moved the camera closer to the -Y edge (right on the picture) of the dichroic (POP_beam_clearance_extreme.jpg) and it still looks OK.

If it's hard to understand what was done, look at the annotated photo (the last attachment After_stiffener_installed_annotated.jpg), the cellphone camera was inserted to "Camera" position.

REFL beam path:

I confirmed that the long stiffener beam doesn't interfere with the motion of the REFL beam diverter. Also, when the REFL beam diverter is open, I looked into the last steering mirror for the REFL air path from the viewport position to make sure that the short stiffener beam won't occult the REFL path.

Some hiccups:

We used D2500433 -11 variant S/N 4 and -1 variant S/N1 even though page 11 of T2500339 suggests it should be -10 and -2 variant, respectively.　We didn't have -10 variant, and -2 variant was absolutely too short.

B&K

We performed B&K hammer measurements before/after the stiffener installation for POP periscope. Before, there was a 70Hz-ish peak. After, it was pushed higher up in frequency. The transducer was attached to the ISI table and Jim hammered the top of the periscope.

Likewise we did B&K test for the input periscope of the JAC even though it was not absolutely necessary.

We haven't done B&K for the JAC output periscope because it's not even fully clamped down (we will move it).

Jim will post the data.

INS, ISC

Images attached to this report

H1 General - Ops Day Shift End

oli.patane@ligo.org — Tue, 20 Jan 2026 16:29:36 -0800

Author: oli.patane@ligo.org

Report ID: 88821

TITLE: 01/21 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: Continued alignment for HAM7, and BNK measurements on HAM1 periscopes. Currently the LVEA is LASER HAZARD
LOG:

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
15:37	FAC	Randy	LVEA	n	Craning rails (started at 15:15)	16:09
15:37	FAC	Nellie	LVEA	n	Tech clean	16:21
16:11	FAC	Randy, Corey	LVEA	YES	Craning	17:23
16:31	VAC	Travis	MX, EX	n	Turbo pump tests	21:10
16:35	SQZ	Sheila	LVEA	YES	HAM7 alignment	19:43
16:51	FAC	Nellie	LVEA	YES	Tech clean	17:30
16:57	TCS	Matt	JOAT Lab	n	Building up second table	19:21
17:17	SEI	Jim, Keita	LVEA	YES	BNK	19:52
17:23	PEM	Robert	LVEA	YES	Mounting accelerometers	18:53
17:37	SQZ	KarMeng	LVEA	YES	HAM7 alignment	19:43
17:37	SAF	LVEA IS LASER HAZARD	LVEA	YES	LVEA IS LASER HAZARD	20:30
17:46	FAC	Randy, Corey	LVEA	YES	Craning	19:00
18:09		Matt	LVEA	YES	Grabbing laptop	18:26
18:13	VAC	Jordan	MY, EY	n	Turbo pump tests	22:04
19:04	SEI	Rahul	LVEA	YES	Helping Jim	19:24
19:17	PCAL	Tony	PCAL Lab	y(local)	Getting ready for a measurement	19:24
19:22	FIT	Matt	YARM	n	Running	20:30
19:43	SAF	Corey	LVEA	YES	Transitioning to Laser SAFE	20:03
20:09	EPO	Mike, Rana, tour	LVEA	n	Tour	21:09
20:33	EE	Fil	LVEA	YES	Cabling	00:17
20:41	FAC	Randy	LVEA	n	Securing railing	21:09
21:10	SAF	Tony	LVEA	YES	Transitioning to laser HAZARD	21:28
21:12	SQZ	Sheila, KarMeng	LVEA	YES	HAM7 alignment	22:34
21:40	FAC	Tyler	LVEA, MX, MY	YES	3IFO checks	23:40
21:52	VAC	Travis	Optics Lab	n	Grabbing tool	21:58
22:08	JAC	Jason	LVEA	YES	Parts hunting and FARO spot hunting	22:31
22:46	PCAL	Tony	PCAL Lab	y(local)	Finding case for beamsplitter	23:17
22:49	PEM	Robert	LVEA	YES	Mounting accelerometers	ongoing
22:49	SAF	LVEA IS LASER HAZARD	LVEA	YES	LVEA IS LASER HAZARD	ongoing
22:50	JAC	Jason, Jennie	Optics Lab	n	Hunting for parts	23:02
00:18	SEI	Jim, Keita	LVEA	YES	BNK measurements	00:20

H1 SQZ - HAM7 progress

karmeng.kwan@ligo.org — Tue, 20 Jan 2026 16:06:06 -0800

Author: karmeng.kwan@ligo.org

Report ID: 88806

[Sheila, Karmeng]

FC1 alignment was adjusted to account for the buoyancy, and we coaligned the FC1 green/IR beam. We managed to recover the FC refl green on SQZT7 periscope, but not on the photodiode.

The OPO IR transmission is misaligned, and we managed to recover the IR on SQZT7 PD. As we recovered the IR refl (top) on SQZT7, we saw an improvement from ~600 to ~1680 (we may have been clipping on the refl PD previously).

By changing the setting on ZM2, we managed to improve the IR trans (bottom).

Old setting ZM2 PIT: 424 ; YAW: -235

New setting ZM2 PIT: 444 ; YAW: -315

Will need to check on the iris tomorrow, to make sure we did not deviate from the original path.

SQZ

Images attached to this report

H1 SQZ - Comment to VOPO measurement setup

corey.gray@ligo.org — Tue, 20 Jan 2026 15:19:48 -0800

Author: corey.gray@ligo.org

Report ID: 88811

Tagging EPO for photo of fur-low scientist.

H1 SUS - Comment to HRTS OM0 Optic-Prisms glued and then shipped to LLO

corey.gray@ligo.org — Tue, 20 Jan 2026 15:17:38 -0800

Author: corey.gray@ligo.org

Report ID: 88810

Tagging for EPO.

EPO

H1 ISC - Comment to JAC beam into HAM2 but not out yet (Jennie, Masayuki, Jason, Keita)

corey.gray@ligo.org — Tue, 20 Jan 2026 15:17:02 -0800

Author: corey.gray@ligo.org

Report ID: 88809

Tagging for EPO

EPO

H1 IOO - Comment to HAM1 optics alignment

corey.gray@ligo.org — Tue, 20 Jan 2026 15:16:24 -0800

Author: corey.gray@ligo.org

Report ID: 88808

tagging for nice JAC team photo for EPO.

EPO

H1 SUS - eMod Railing and Spiral Staircase Installed

corey.gray@ligo.org — Tue, 20 Jan 2026 15:15:11 -0800

Author: corey.gray@ligo.org

Report ID: 88807

(Corey Gray, Randy Thompson)

This morning (during mostly laser Hazard) I assisted Randy with work on the eMod Platform. The eMod platform is the elevated large work platform which is installed over the TCSx In-Air Table and next to BSC3. The eMod is an additional workspace to be used for the installation of the BBSS (Big BeamSplitter Suspension) into BSC2 in the coming months.

Today, we craned up handrails and installed them in place. After this we rolled the white powdercoated spiral staircase into the LVEA from the HiBay and then used the crane to position the stairs next to the eMod. The stairs were attached to the eMod floor via qty 3 long 3/8-16 bolts. (attached is a top-view photo of the installed stairs).

After this we cleaned up our area and then staged the new horizontal HEPA filter assembly which will be used later for the BBSS installation.

EPO, SUS

Images attached to this report

LHO VE - Quarterly Functionality Test Performed on EY/MY Turbo Pumps

jordan.vanosky@ligo.org — Tue, 20 Jan 2026 14:46:24 -0800

Author: jordan.vanosky@ligo.org

Report ID: 88805

Procedure checklist for both stations completed.  No issues were identified at this time.

MY: Scroll pump hours: 99.9
       Turbo pump hours: 238
       Crash bearings: 100%

EY: Scroll pump hours: 91.1
       Turbo pump hours: 1299
       Crash bearings: 100%
 
Closing WP 12986 FAMIS 31281 and 31289

LHO VE - Quarterly Functionality Test Performed on EX/MX Turbo Pumps

travis.sadecki@ligo.org — Tue, 20 Jan 2026 13:38:12 -0800

Author: travis.sadecki@ligo.org

Report ID: 88804

FAMIS tasks 31322 and 31307, WP 12977

Procedure checklist for both stations completed. No issues were identified at this time.

MX: Scroll pump hours: 238.6
Turbo pump hours: 150
Crash bearings: 100%

EX: Scroll pump hours: 7159.1
Turbo pump hours: 1111
Crash bearings: 100%

H1 ISC - Comment to JAC beam into HAM2 but not out yet (Jennie, Masayuki, Jason, Keita)

jennifer.wright@ligo.org — Tue, 20 Jan 2026 12:59:30 -0800

Author: jennifer.wright@ligo.org

Report ID: 88803

Photos of trying to find the beam out of HAM2. I think the photographer was Jason and in the foreground is Keita, with Masayuki in the background.

EPO

Images attached to this report

H1 IOO - Comment to HAM1 optics alignment

jennifer.wright@ligo.org — Tue, 20 Jan 2026 12:55:55 -0800

Author: jennifer.wright@ligo.org

Report ID: 88802

Pictures for posterity.

EPO

Images attached to this report

LHO VE - Tue CP1 Fill

david.barker@ligo.org — Tue, 20 Jan 2026 10:15:16 -0800

Author: david.barker@ligo.org

Report ID: 88800

Tue Jan 20 10:09:37 2026 INFO: Fill completed in 9min 33secs

Images attached to this report

H1 General - TCS Chiller Water Level Top-Off - BiWeekly

anthony.sanchez@ligo.org — Tue, 20 Jan 2026 09:41:07 -0800

Author: anthony.sanchez@ligo.org

Report ID: 88799

FAMIS 27832 TCS Chiller Water Level Top-Off - BiWeekly.

	TCS X	TCS Y
Previous Level	29.9	9.9
New Level	30.5	175
Water added mL	250	10.4

Values added to spreadsheet.

H1 CDS - Workstations updated

erik.vonreis@ligo.org — Tue, 20 Jan 2026 08:21:52 -0800

Author: erik.vonreis@ligo.org

Report ID: 88798

Workstations were updated and rebooted. This was an OS packages update. Conda packages were not updated.

H1 General - Ops Day Shift Start

oli.patane@ligo.org — Tue, 20 Jan 2026 07:36:26 -0800

Author: oli.patane@ligo.org

Report ID: 88797

TITLE: 01/20 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 9mph Gusts, 5mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.25 μm/s
QUICK SUMMARY:

Tuesday Maintenance Day today, but also we will be wanting to go back to Laser Hazard for the morning to finish up the HAM7 alignment, before doing some back and forth to and from laser safe.

H1 SQZ - Comment to HAM7 ZM4 alignment

sheila.dwyer@ligo.org — Mon, 19 Jan 2026 21:59:52 -0800

Author: sheila.dwyer@ligo.org

Report ID: 88796

Friday, we recentered the beam onto the OPO pump fiber rejected PD.

Robert and I also went to the chamber in laser safe in the afternoon and reattached the cable clamp to the pillar on the hard to reach side of the VIP, and took phots of the camble routhing and iris locations.

Since we adjusted the alignment of B:M4 while moving the beam location in SFI2, we had to realing the path to the FC QPDs as Kar Meng mentioned above. We did this using the seed beam because that beam can be seen on a card, but it saturated the QPDs. We walked the pointing until the beam was on both QPDs as seen by saturating all the quadrants, we will want to use the CLF beam to actually center on these QPDs so that we aren't saturating.

Still to do in HAM7 in laser hazard:

The green filter cavity beam seems to be misalinged relative to the IR, we noticed this in December. Now that we feel confident about the IR alignment we need to come back to the green alignment.
Decide what to do about the OFI PD A path, which will no longer be aligned because of our move of the spot in SFI2. (Probably blocking it)
unlock VIP
photograph beams on irises
revisit the power budget one more time, writting down the measured power levels both in the OPO trans path and the reflection path

Not in laser hazard:

remove irises
unlock ISI
SUS and ISI health checks

LHO VE - Mon CP1 Fill

david.barker@ligo.org — Mon, 19 Jan 2026 10:25:07 -0800

Author: david.barker@ligo.org

Report ID: 88795

Mon Jan 19 10:09:49 2026 INFO: Fill completed in 9min 46secs

Images attached to this report

LHO VE - Sun CP1 Fill

david.barker@ligo.org — Sun, 18 Jan 2026 10:17:26 -0800

Author: david.barker@ligo.org

Report ID: 88794

Sun Jan 18 10:12:10 2026 INFO: Fill completed in 12min 6secs

Images attached to this report

LHO VE - Sat CP1 Fill

david.barker@ligo.org — Sat, 17 Jan 2026 10:28:38 -0800

Author: david.barker@ligo.org

Report ID: 88793

Sat Jan 17 10:12:35 2026 INFO: Fill completed in 12min 31secs

Images attached to this report