S. Muusse

Calibrating sensors

I have been working on calibrating the sensors on the cheta tables. When calibrating the power at the pick off  that will be used to monitor CHETA power on ITM using beckhoff I was seeing voltage jumps up to saturation at 2.5V as shown in attached plot. This was determined to be due to the auto range on the thermal power head being on. This setting was turned off ( as outlined in T2600081 ) and a range of 0-22mV was selected as max incident power was ≈ 11mV.  After which a linear relationship was observed and shown in the attached plot. The laser power vs laser current and the measured V vs laser current have been takem but I havent calculated the responsivity value for the beckhoff screen yet. 

Profiling CHETA beam 

The beam profiler has been shipped back from LLO to check the alignment against the model and profile the beam size as the second lens is moved by the translation stage. This is how we aim to control the CHETA beam size.
On the Y-table the beamsize was measured over a 60mm distance and the profile was fit with a non linear fit for w0 and z0 setting M2 =1. This is shown in the attached plot.

--- Horizontal (A1) Fit ---

Fit converged: w₀=896.3+/-37.1 µm, z₀=-528.0+/-47.8 mm

Model: w₀=1020.9 µm, z₀=-704 mm

--- Vertical (A2) Fit ---

Fit converged: w₀=977.3+/-40.1 µm, z₀=-449.0+/-40.1 mm

Model: w₀=999.36 µm, z₀=-459 mm

The vertical fit agrees for both w0 and z0 within the fit uncertainties and the horizontal profile was just outside the uncertainty bounds. 
Subsequently, the beamsize has been measured along the same positions with L2 at its minimum and maximum displacements on the translaiton stage (±50mm) but this data hasnt been processed yet at will be added in a comment. 

TITLE: 03/11 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Corey
SHIFT SUMMARY: Busy day of IFO recovery, mostly in the form of hunting for beams and putting them in their appropriate places. See alogs from others for more detailed accounts of the day (such as alog89469). The wind has been picking up and doesn't look to be calming down until tomorrow, which has been making locking the arms difficult when desired.
LOG:

TITLE: 03/11 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: Ryan S
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 41mph Gusts, 30mph 3min avg
    Primary useism: 0.10 μm/s
    Secondary useism: 0.31 μm/s 
QUICK SUMMARY:

Got an overall summary on the status of H1 recovery from RyanS.  

Fil, Patrick, Jonathan, Erik, Dave:

Fil connected the IOT1 JAC digital camera to the CER POE switch (sw-lvea-aux 0/4).

Erik added the new camera to DNS as h1cam38 (10.106.0.61).

Patrick added this camera as the first cam on h1digivideo6, using the multicast address 239.192.106.67

I added the camera to camera.yaml and updated the camera overview MEDM (see attached).

The camera is currently in a dark location, so no image.

Sheila, Ryan S, Jennie, Jenne, Control Room...

Ryan started with green initial alignment and got PRX locked 69467.

Sheila  continued yesterdays work looking for signals in the REFL path. Could again get signal on ASC REFL B but not A. She measured PRX OLG, see attached, it's a bit below the reference.

Sheila reset the LSC POP A 45 dark offsets that are hard coded in ALIGN_IFO PREP XARM state.

Sheila set up some sine oscillations on PM1 and RM2 to try to find the beam on the POP diodes in HAM1. 

Jennie/e and I then reset IM1,2,3,4 to a November time 2025/11/16 15:34:24 UTC (ndscope on cdsws44 had some issues with this yesterday). And then we walked IM3 and IM4 to get IM4_TRANS and ASC-POP_A back to this time which was quite different IM3/4 alignments. ASC-POP_B ended up not too far off. Plot of now and November attached. In particular, IM3 and IM4 PIT OSEMs are 200 and 400urad different than November. 

Ryan and Jenne improved Xarm IR transmission via PR2. 

Wed Mar 11 10:03:46 2026 INFO: Fill completed in 3min 44secs

Quick fill, LN2 was burping after yesterday's fill for a few hours.

TITLE: 03/11 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 21mph Gusts, 16mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.33 μm/s 
QUICK SUMMARY: Breezy night with a few small earthquakes rolling through. More alignment work today, and the IFO right now is DOWN, but I'll start with a fresh ALS alignment of the arms then go into BS and possibly PRX alignment (I'll see how far I get) to give us a good starting place to go from today. In other news, the JAC and IMC stayed nicely locked overnight except for one dropout when an earthquake hit.

TITLE: 03/11 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:
Comissioning team is leaving the IFO in Down tonight due to mis alignment somewhere between the Power recycling cavity and JAC ~  1:25 UTC. 
 

Camilla, Betsy, Oli

We've made some good progress the last couple of days for the BHSS.

Yesterday I moved the four tiny BHSS beam dumps onto the center of the BHSS next to the BHSS optics. I then carefully wrapped up the BHD sled and table optics mounts (who still don't have optics in) to make some more space on the table. Each mount was gently double wrapped individually in foil, with the mounts with black glass being covered with an optics cloth. Then I grouped and wrapped everything into four big packs: sled lens mounts, sled mirror mounts, table lens mounts, and table mirror mounts. These packs were put aside and left a lot more room on the table. Tomorrow we will double bag and label them to get them off the table.

This morning Betsy and I went into the Triples Lab and glued the viton tips to the OMC cradles and the screws, and those are in the oven and will be taken out tomorrow morning.

Yesterday I also discovered that the BHSS Alignment Tooling Plate (D2400074) needed to be helicoiled, so today I helicoiled it and then put it together on the BHSS. After installation, I needed to remove it and the supporting posts (D2400117), and when trying to reinstall the posts I discovered that one had been gouged and I couldn't get the screws in very far. I was able to get a screw in the other post (proving that it wasn't the screw), and then this post also got messed up. I ended up just standing one of the support posts under where it needed to be. The other post was too loose under the tooling plate (we probably need to loosen a couple of the earthquake stops on one side of the BHSS), so Camilla jigged up a washer + longer set screw combo that held onto the plate and the little amount of the post that wasn't messed up.

We turned on the laser and measured the power before and after the fiber. Before the fiber was 4.5mW and directly after was 1.83mW. With this power we did some rough beam alignment and were successfully able to get the beams to the second iris along each path (layout pic). Tomorrow we do fine-tuning.

TITLE: 03/10 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 17mph Gusts, 13mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.29 μm/s 
QUICK SUMMARY:

There is a concentrated effort to integrate & align JAC into the IFO.
Camilla wrote up some quick locking notes up to 00:00 UTC 

Currently working out PR alignment.   

 

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

The new purge air compressor, Kobelco KN-0, developed a very small leak a few weeks ago, it was first noted on 1/30/2026, I notified the vendor the same day.  About a week later they sent a technician over, the technician did diagnosis of the unit and determined that the unit was leaking oil.  The leak was located at the oil pump body, and after a conversation with his supervisor they decided to replace the pump "because some of them just leak from the start".  But they needed to order the pump and it was going to take a few weeks.  Also, due to an active vent, we decided to continue using the system as it was.  But, we did increased our visits to the unit to twice daily.

     This is an excerpt from the report regarding the leak: 
"INSPECTED UNIT AND DISCOVERED LEAKS OUT OF 3 DIFFERENT LOCATIONS IN 
THE OIL PUMP HOUSING. APPROXIMATELY 3-4 OUNCES OF OIL WAS IN THE 
BOTTOM OF THE CABINET, BUT NO ACTIVE DRIPS WERE VISIBLE. JUST RESIDUE 
ON SEAL LOCATIONS AND A PUDDLE DIRECTLY BELOW."

Fast forward to today (3/10/26), two technicians showed up to replace the oil pump, no issues were encountered during the replacement.  Due to the leak and the oil pump replacement the oil was a bit low, the technicians topped the unit with oil.

      This is an excerpt from the report regarding the oil pump replacement:
"TRIP 2: OIL PUMP REPLACEMENT ON ABOVE KNW 0. REMOVED OLD PUMP WITH 
LEAKING SHAFT, REMOVED FITTINGS AND PLACED FITTINGS ON NEW PUMP. 
REPLACED THE COUPLING AND ENSURED PROPER DISTANCE TO MOTOR 
COUPLING ELEMENT. TOPPED OFF OIL LEVEL.TIGHTENED ALL FITTINGS, HOSES 
AND BOLTS. TEST RAN UNIT FOR PROPER CYCLING AND LEAKS FOR 30 MINUTES.
TOOK READINGS - LEFT UNIT OFF."

The compressor is now off.  Closing WP-13081

Ryan C, Sheila, Jennie, Jenne, Camilla, Ryan S, Daniel

Ryan got the green arms locked and then Sheila and I went on ISCT1 to improve the COMM and DIFF beatnotes, to +2dB and -10dB.

Dave and Ryan fixed a ISC_LOCK Channel not found error. 

Sheila then aligned MITCH and started to check the phasing using 'ndscope sheila.dwyer/ndscope/LSC/phase_LSC_9_and_45.yaml'. Comparing to November, screenshot attached. First AS_A_RF45 was rephased after WFs were centered, needed +90deg. See sdf's attached. All LSC 45's were then phased following the same +90deg. Check REFL 9 with a swinging MICH and decided it was close enough. No LSC RF9's were changed. 

There were some pauses for JAC table work. 

Ryan then re-ran green initial alignment (wasn't done this AM), checked beatnotes were still fine. Jenne, Jennie and Sheila locked ALS and locked MICH. 

Sheila needed to revisit PRX alignment as struggling to find POP beams.

Jenne realized the mode cleaner isn't using DOF3, it used to feedback to the PZT, but now needs to feedback to JM3.

Daniel did the IMC phasing of WFs. 

Jennie W, Jenne D

We need to check the positions of IM1 and 2 as we have now closed all 3 loops for the IMC alignment.

Jenne was windering how our input alignment to the IFI compares to before the vent.

We compared the IM 1 and 2 pitch and yaw positions in manual initial alignment between today and the 12th of December - when we were doing our last locking before the vent.

This comparison is during manual initial alignment which is state 8 in the ISC_LOCK guardian.

The first pic is the 12th December, reference time is 05:21:30 UTC.

The second pic shows today with y cursors at the reference values. The biggest difference is IM2 pitch which is ~120 counts lowewr than it was, the other 2 DOFs are tens of counts off.

I also included IM3 and 4 in my plots but I think we have intentionally changed IM3 since the vent to improve alignment onto IM4 trans and IM4 is controlled.

TITLE: 03/10 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Tony
SHIFT SUMMARY: Alignment work today, green arms, Xarm IR, MICH, PRX alignment is being worked on as of the end of day shift.
LOG:                                                                                                                                                                     

• 16:00 TEST T629846
• Sheila and Camilla went out to ISCT1 and fixed up the ALS beatnotes, DIFF went from ~ -12.0 -> ~ -10.0, and COMM went from ~ -33 to ~ +3.0.
• Sheila unlocked the PSL rotation stage, I turned up the power to 2Ws, Sheila left the PSL rotation stage unlocked.
• 18:41 UTC I restarted standdown_alerts
• 18:48 UTC Firepump testing, 1 & 2
• JAC team encounted an issue regarding a missing cable for the JAC PD shutter
• 20:00 UTC We started to work on the XARM IR alignment
• 20:26 UTC We ramped up to 10Ws for MICH
• The Optics Lab will have a laser running unattended overnight like yesterday, the signs will be put up when people are done working in that lab and the laser is shuttered.

Jenne Driggers, Jennie Wright, Sheila, Ryan Short, Ryan Crouch, Tony

We are running all three IMC ASC DOFs.  Jenne turned on DOF3 pitch without issue once she set up the feedback through JM3.  The YAW DOF was unstable, we checked the output matrix for yaw.  With the gain increased on DOF1+DOF2 we put 10 couns on JM3 pitch test, and measured the responses on MC1, MC2, MC3 outputs from the IMC ASC.  (screenshot attached).  We scaled these responses to give us the new output matrix, this worked well once we flipped the sign.  We accepted these changes in SDF so they should be used everytime the IMC locks from now on. 

In the process we remembered that IMC ASC has the intergrators in the asc model, not the suspensions. 

Turned laser on first thing and Marc turned on the SQZ High Voltage in the Mech room mezzanine 89449, the PMC and SHG looked without issue. I turned back on the SFI1, SFIO2 and OPO TEC servos (were turned off for venting).

Segment 3 of H1:SQZ-RLF_QPD_A_SEG_3 is broken 89020, so we will need to decide what to do about that but I didn't do anything yet. 

Increased SEED light from 0.5mW to 75mW, then LOCKED_SEED_DITHER, power was then 0.1 mW on SQZT7, previously ~2mW. Checked QPD B, power now 13nW, previously 130nW, for similar CLF_TRIG reflected power. see attached. Can try to realign via QPD_B and ZM2,3 but have not yet done this. 

Changed OPO temp from 31.72 to 33.703 while injecting CLF and scanning the OPO PZT to coalign green and IR peak (Sheila said SEED may have been quicker).

OPO with CLF still didn't lock. With H1:SQZ-OPO_PZT_1_SCAN_TRIGGER_CHANNEL_1_LEVEL and 2_LEVEL reduced from 0.5 to 0.1 and it debatably locked looking at  H1:SQZ-OPO_IR_RESONANCE_CLF_RF but with no signal on H1:SQZ-OPO_IR_PD_DC_POWERMON... maybe the alignment is just very bad.

Pausing here.