I transitioned to laser hazard once the door crew broke for lunch and Camilla and I looked at where the JAC Refl beam comes through.  It is (expectedly) coming out a bit off center (1.5" off in yaw and less than 1" off center in pitch) but with a bit over 5" on the clear aperture of the viewport window we (and Keita and Sheila) are all good on this pointing.  Camilla transitioned back to laser safe and the door crew is going back at it.

JM1 looks good in transfer functions and is ready for doors!

We wanted to verify that our current offsets for JM1 (specifically Y:-840) is not near the edge of our physical range or DAC range.

Initially I had tried taking transfer functions for JM1 with the OPTICALIGN offsets ON, but that limits the amount we can drive so as to not saturate, but that then gives us really bad coherence (and purge air doesn't help). Luckily we can still see the peak locations, and since the frequencies haven't shifted, that means that we aren't close to touching.
I then compared the MASTER_OUTs for JM1 and RM2 (who also has a large OPTICALIGN Y: +935) with the offsets ON. The signal chain for these two are the same so they should be comparable. I found that RM2 has a higher min/max in the MASTER_OUTs, and that value is only half the max DAC range, so JM1 is also fine DAC-range-wise.

After confirming that I turned the OPTICALIGN offsets OFF and took transfer functions. They look good and match the initial set taken in December! 

Settings:
- ISI LOCKED
- DAMP OFF
- OPTICALIGN OFF (too hard to get good coherence without saturating with offsets on)
Data:
/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/JM1/SAGM1/Data/2026-02-26_0015_H1SUSJM1_M1_WhiteNoise_{L,P,Y}_0p02to50Hz.xml
Results:
/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/JM1/SAGM1/Results/2026-02-26_0015_H1SUSJM1_M1_ALL_TFs.pdf
r12924
Comparison:
/ligo/svncommon/SusSVN/sus/trunk/HTTS/Common/Data/allhttss_2026-02-26_JM1_Dec2025vsFeb262026_ALL_TFs.pdf
r12927

*The jump in magnitude between these measurements and the previous is due to a factor of 4 that accidentally got removed. See 89198

Yesterday, ground loop checks revealed a new and random ground loop issue on the LR BOSEM of the Tip Tilt PM1 suspension (which has been installed and used in vac for a long while now).  This morning I worked to swap the BOSEM for a new one, reset the medm offset/gains and recentered.  Fil confirmed that the ground loop situation is now resolved on PM1.  In Corey's absence, I took a bunch of photos (won't be as good as his but here for posterity) of the chamber components as we see them before closing up.  I wiped down some of the under table surface as I could.  Jim and I both inspected for left behind items on and under the table.
BOSEM SN 263 is the problem OSEM removed, SN 229 was swapped in with OLV 28860.

Jim then removed the septum viewport covers (all 4)and unlocked the ISI.  Oli ran the final closeout TFs for PM1 (JM1 and JM3 were yesterday).  I revisited the closeout check sheet and we launched the door crew (Jordan, Randy, and FAC - thanks for jumping in due to others absences!).  1 door is on now and we are about to check that the JAC Refl beam goes through the viewport on the door as anticipated given the inaccuracy of the viewport simulator fixture.

Thu Feb 26 10:06:39 2026 INFO: Fill completed in 6min 35secs

TITLE: 02/26 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: 6mph Gusts, 3mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.26 μm/s 
QUICK SUMMARY:

HAM1 work is quickly heading towards doors!

The default workstation conda environment was updated.  ndscope is updated to 0.20.7.  A list of changes can be found here: https://git.ligo.org/cds/software/ndscope/-/blob/master/CHANGELOG.md.

tmux and some other system commands were dropped from the conda environment.  tmux should now work in the terminal.

(Travis S., Jordan V., Randy T., Gerardo M.)

Wednesday afternoon we had the opportunity to remove and replace the annulus ion pump body for BSC8 annulus system.  To reach the ion pump body we used the scissor lift that Randy moved near the chamber.
No issues were encountered on the removal or installation of the ion pump body.  The annulus ion pump system was evacuated and we left it pumping down with an aux cart and a small "can" turbo.  On this system we used a noble diode pump, which required us to replace the controller for a positive one.  Setpoints were set on the aux cart and at the end of the day the annulus system had reached below 5.0x10^-05 Torr.

S. Muusse, C. Compton, G. Valente

Alignment of 4.65um beam on the ITMY was completed, excluding the QPD optics which require reflection off the ITM. I've attached a picture of the almost complete table with the notable optics modified today indicated. I'll get someone taller to add a better picture in the comments of the whole table.

• All the PD optics were placed and aligned (another picture).
• The PD electronics (x-arm Chassis & PD power supply) were temporarily installed and slow and monitor channels were shown to be operational.
• Thermal pickoff aligned.
• The beam dump flipper orientation has been problematic but has been solved by dumping when the flipper is vertical and placing the beam dump at a ≈ 30deg angle (picture attached).

Next steps:

• Installing the visible laser and associated optics
• Testing the rotation mount and translation mount
• Testing y-arm chassis

The Medm screen is now in a workable form if not particularly finessed.The screen is called TCS_CHETA.adl and a shortcut was added for the X and Y arms by camilla to the TSC screen.
There is still work to be done here calibrating the powerdetectors and power meters.
note: currently power in for the rotation mount .adl is the laser diode current and should be changed to laser power when calibrated

TITLE: 02/26 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY: More HAM1 work done today, we're very close to closing
LOG:
Sophie will post log as comment

J. Freed, J. Warner

We set up a small rack to be put into the optics lab for the SPI build housing (most) SPI electronics and hooked up all the power cables for these electronics (For the build we are using a dual source RF generator to instead of the 80MHz OCXO and Single Sideband Mixer like in the final set up). Before this set up can be used, a RF power meter should to be used to check to make sure the correct RF power is going to the AOMs in the SPI laser prep chassis. 

After applying power to the TIA chassis I also checked that the DB25 on the front panel of varient 2 of the TIAs was correctly outputing -15V on pins 1-10. 

Results:

Pins 1-4,7-10 were outputing -14.8V

Pins 5-6 were outputing -15.1V

This discrepancy in pins power is expected and is caused by the fact that the Variant 3 TIA is the one that is actually powering pins 5-6 through the front panel DB9 cable from varient 3 to varient 2. 

J. Kissel, R. Short, J. Oberling

This is the first installment of aLOGs documenting the setup of a new stand-alone 1064 nm NPRO laser system whose current "end game" intent is to provide ~100 [mW] of fiber-coupled p-pol light to the SPI laser prep chassis.

Step 1: Gathering materials, find what optics / mounts we had vs. what would be need, and physically layout the plan.

Jason lets Ryan and I know that there are three NPROs in the optics lab, two of which are PSL spares that cannot be used. 
The remaining laser is S/N 1661, the laser used in the PSL during O3 which is *functional* but was briefly installed during O4 circa Fall/Winter 2024 then removed from use in the PSL because of reported glitching / incompatibility with the frequency stabilization servo (FSS) issues -- see the bottom of LHO:81391 for a nice summary, and LHO:81409 for record of its removal.

Inspired by the setup at Stanford Sina shared with us, we're looking to build up the following system to accomplish the goal:
    - NPRO (presumed to be elliptically polarized with Is / Ip = 5:1)
    - QWP (to linearize the polarization)
    - HWP1 (to rotate the polarization into horizontal)
    - FI (accepts horizontal linear polarization, to ensure back-reflections from down-stream components don't seed the NPRO causing glitches/mode hopes/frequency noise)
    - HWP2 (to rotate the FI output polarization into the desired amount of vertical polarization -- aka the desired amount p-polarization)
    - PBS (to filter out and dump the unneeded horizontal / s-pol light, and transmit the desired power of p-pol)
    - SM1 (one of two steering mirrors to align the beam into the fiber collimator)
    - L1 (the single-lens mode-matching solution to convert the NPRO beam into what the fiber collimator needs)
    - SM2 (two of two steering mirrors for alignment into the fiber collimator)
    - 50:50 PWR BS (45 [deg] AOI, optimized for p-pol; to provide a pick-off port for live power measurement)
    - Fiber Collimator

Ryan started with a 24" by 12" breadboard that was lying around in the optics lab. He build up a makeshift stand from three posts and dogs in the lower left corner such that the S/N 1661 NPRO projects the beam at 4" height. The 0.5" thick breadboard has a 1 inch hole pattern offset by 0.5" from the edges. I'll refer to this grid as having axes "m" and "n" where the m-axis are the "row" holes running from 0 to 23, and the "column" n-axis holes run from 0 to 11. I chose (m,n) breadboard coordinates so as to not confuse them with traditional beam profile coordinates of (z [propagation distance], x (transverse horizontal), y (transverse vertical)). 

Thus, the NPRO being in the "lower left" means it projects the beam along the m = 3 row, and the front face of the NPRO is sitting at n = 8. We'll call this beam position z = 0.

We then proceeded to gather as much as we could of optical components from the optics lab drawers, and ended up with this pictured preliminary version of the setup.

Step 2. Power up the NPRO.
Here's were we ran into our first snag. Normally, NPROs are paired/tuned with specific controller boxes. However, when Ryan turned on the S/N 1661 laser with the S/N 1661 control box, the crystal temperature readback reported the temperature was quickly, linearly rising well beyond the desired temperature of 24.7 [deg C]. At ~42 [deg C], (but still below the internal automatic watchdog threshold of 50 [deg C]), Ryan knew something was wrong and turned it all off. He repeated the turn on just in case, and it did the same.

After conversing with Jason, we figure it's good enough to run with one of the other controllers for now, and in the mean time figure out how what's wrong and repair the S/N 1661 controller.

So, we're running with the S/N 7974, and things seem fine. 
    Laser Diode Temp Setup:
        Diode 1 33.7 [deg C]
        Diode 2: 33.1 [deg C]
        Laser diode injection current readback 2.08 [A] (for both diodes)
    Crystal Temp setting is 24.7 [deg C]

We measured the output power*** with no optical elements at all as 1.820 +/- 0.005 W (not noisey, but a slow drift around).
Good enough! Onward and upward!

*** Power measured by ThorLabs power meter
	Model S302C
	SN 111149
	Sensing factor of 316.25 [mV/W]
	(last calibrated Feb 3 2012).

F. Clara, K. Kawabe, M. Pirello

We checked the following for ground loops:

CER:
Beam Diverter Cables - Both tested good.

From SUS R1:
JM1 is good
JM2 is good
JM3 is good
PM1 - Pin 2 is grounded, Shield is not connected to pin 13 (cable HAM1_311)
RM1 - Shield is not connected to pin 13 (cable HAM1_228)
RM2 is good

From ISC Racks:
ISC_222 (db9) pin 5 not tied to shield, signals good
ISC_221 (db9) pin 5 not tied to shield, signals good
ISC_226 (db9) pin 5 not tied to shield, signals good
ISC_356 (db25) pin 13 IS tied to shield, signals good
ISC_223 (db25) pin 13 not tied to shield, signals good (older cable)
ISC_224 (db25) pin 13 not tied to shield, signals good (older cable)
ISC_225 (db25) pin 13 tied to shield, signals good (new cable)
ISC_227 (db25) pin 13 tied to shield, signals good (new cable)

EOM RF Signals:
At Rack, all RF signals shields are tied to rack ground.
Cable runs are isolated from rack and chamber ground
At Chamber, all RF signal shields are tied together in chamber possibly at EOM.

IOT2 Table Enclosure:
Picomotor Cable - pin 13 tied to shield, signals good.

h1susb123 accumulated 4 DAQ CRC errors on the 1-leg overnight as reported by DC1, but none on the 0-leg.

All 4 models on h1susb13 increment their CRC counters at the same time. Normally we have zero CRC errors for weeks/months across the board.

I have cleared the CRCs and we will see if this trend continues.

The annulus ion pump body for the BSC1 annulus system was replaced.  We then hooked up and started the turbo/aux. cart.  Pressure at the cart was dropping nicely as pumping commenced.  

There will be a pump cart running on the south side of the Y-arm beamtube, near the TCSY table, until the ion pump transition pressure.

Rahul, Fil, Oli

We still don't know why PM1 looks different now than it did when we installed it back in May 2025. Currently, we've nailed it down to two possibillities: (1) there's an issue with PM1 somewhere between the satamp and the in-chamber stuff, or (2) the December 2025 satamp swap to a modified satamp changed the magnitude of PM1 (we are not sure if this makes sense).

Here are some measurements we took yesterday and the things we've looked at so far.

Satamp

We were worried about the satamp, which is a dual satamp, swapped in in December 2025 (88590), with JM3 taking up the other half, so I took some transfer functions yesterday morning for both PM1 and JM3. I compared JM3 now to how it looked when we first installed it in December 2025, and it looks exactly the same, no drop in magnitude for JM (JM3 Dec2025 vs Feb 2026), and no increase in magnitude for PM1 (PM1 May 2025 vs Feb 2026).

Fil then swapped all the PM1 cables on the satamp with all the JM3 cables on the satamp. This made it so the only difference between the previous and these measurements is the part of the satamp used. These measurements for PM1 and JM3 still looked the same as the earlier measurement, so it's not the satamp (PM1 JM3 comparison). These comparison plots really show how much PM1 changed compared to JM3.

All other in-air electronics

The only other difference from the measurements last May for PM1 should be the coil driver, since the other one failed (88998). The new coil driver is modified, just like the old one, and is being correctly compensated for in the coil drive filter banks. To check this, as well as the rest of the in-air electronics, Fil swapped everything back to nominal EXCEPT for the cables that run from the sat amp out to the chamber. This way, JM3 is using the in-air electronics from PM1, and PM1 is using the in-air electronics from JM3. I did a few transfer functions looking for any difference but both suspensions and electronics chains still look the same(PM1 L, PM1 P, JM3 P). This could mean that the issue with PM1 is due to something in the satamp-to-chamber cable or in vacuum.

OSEMs

We checked the spectra for the PM1 BOSEMs but we did it while the purge air was up, so they're very noisy and not very useful.

Satamp question

The only other thing we can think of that could've changed the magnitude of PM1 but not affect what we're seeing in JM3 would be due to the satamp swap in December. The new modified satamp was hooked up to PM1 and JM3 on December 18, 2025 (88588). JM3 was first tested the next day, and obviously we never got a measurement of JM3 with an unmodified satamp, so if it's possible for the satamp to change the magnitude of PM1, that might be what is happening. I haven't had time yet to check whether other suspensions show anything like that.

Measurement info
PM1
2026-02-18 1600
- ISI Locked
- alignment offsets OFF
- DAMP OFF for measured DOF, ON for other DOFs
Data:
/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/PM1/SAGM1/Data/2026-02-18_1600_H1SUSPM1_M1_WhiteNoise_{L,P,Y}_0p02to50Hz.xml
12905
Results:
/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/PM1/SAGM1/Results/2026-02-18_1600_H1SUSPM1_M1_ALL_TFs.pdf
12909

2026-02-18 1715
- satamp inputs swapped with JM3 (tfs look the same)
- ISI Locked
- alignment offsets OFF
- DAMP OFF
Data:
/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/PM1/SAGM1/Data/2026-02-18_1715_H1SUSPM1_M1_WhiteNoise_{L,P,Y}_0p02to50Hz.xml
12906
Results:
/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/PM1/SAGM1/Results/2026-02-18_1715_H1SUSPM1_M1_ALL_TFs.pdf
12909

JM3
2026-02-18 1600
- ISI Locked
- DAMP OFF
- alignment offsets OFF
- DAMP OFF for measured DOF, ON for other DOFs
Data:
/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/JM3/SAGM1/Data/2026-02-18_1600_H1SUSJM3_M1_WhiteNoise_{L,P,Y}_0p02to50Hz.xml
r12904
Results:
/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/JM3/SAGM1/Results/2026-02-18_1600_H1SUSJM3_M1_ALL_TFs.pdf
r12908

2026-02-18 1730
- satamp inputs swapped with PM1 (tfs look the same)
- ISI Locked
- alignment offsets OFF
- DAMP OFF
Data:
/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/JM3/SAGM1/Data/2026-02-18_1730_H1SUSJM3_M1_WhiteNoise_{L,P,Y}_0p02to50Hz.xml
12907
Results:
/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/JM3/SAGM1/Results/2026-02-18_1730_H1SUSJM3_M1_ALL_TFs.pdf
r12908

Comparisons
PM1 May 2025 vs PM1 Feb 18 2026
/ligo/svncommon/SusSVN/sus/trunk/HTTS/Common/Data/allhttss_2026-02-18_PM1_May2025vsFeb182026_ALL_TFs.pdf
r12911

JM3 Dec 2025 vs JM3 Feb 18 2026
/ligo/svncommon/SusSVN/sus/trunk/HTTS/Common/Data/allhttss_2026-02-18_JM3_Dec2025vsFeb182026_ALL_TFs.pdf
r12912

JM3 Dec 2025 vs JM3 Feb 18 2026 vs PM1 May 2025 vs PM1 Feb 18 2026
/ligo/svncommon/SusSVN/sus/trunk/HTTS/Common/Data/allhttss_2026-02-18_PM1_JM3_PM1looksdifferent_ALL_TFs.pdf
r12910

Ansel, Sheila, Camilla

Last week, Ansel noticed that there is a 2Hz comb in DARM since the break, similar to that that we've seen from the HWS camera sync frequency and power supplies and fixed in 75876.  The cabling has not been changed since, the camera sync frequency has been changed.

Our current camera sync frequencies are: ITMX = 2Hz, ITMY = 10Hz. We have typically seen these combs in H1:PEM-CS_MAG_LVEA_OUTPUTOPTICS_Y_DQ. With a 0.0005Hz BW on DTT I can't easily see these combs, see attached.