Wednesday OPS EVE Shift End

TITLE: 09/10 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Commissioning
INCOMING OPERATOR: None
SHIFT SUMMARY:

The Mega Clean room was Turnt Off. For What!? You may ask? Because we are trying to get closer to our final LVEA temperature for locking the IFO. 
GRB-Short E646174 notification @ 1:24:41 UTC
H1 is now sitting in down er rather Prep for locking..


LOG:
                                                      

Start Time	System	Name	Location	Lazer_Haz	Task	Time End
22:35	vac	VACteam	EY	-	vendor visit to EY	23:50
23:42	VAC	Jordan Gerardo	LVEA HAM7	N	Valving swap on HAM7	23:53
00:40	VAC	Gerardo	LVEA	N	Turning Off the Mega Clean room	00:49

Morning locking to PRMI, oplev damping solution, Afternoon L2P decoupling, DRMI

Sheila, Elenna, Jenne

Morning locking notes

• Jenne completed initial alignment by running green initial alignment and through manual initial alignment for X arm IR, PRX, MICH dark, SR align, and SRY. Except for SR2 align, all alignment was touched up by hand.
• We tried locking PRMI once without oplev damping, however we lost ALS with a large beamsplitter kick.
• The second time we tried locking with oplev damping (using oplev as sensor), and we were successful. PRMI locked for 10 minutes. I touched up the PRM and BS alignment. Sheila still measured a large amount of motion at 0.45 Hz. We think this motion is due to length to pitch coupling on M2.
• I tried engaging the L2P decoupling filter in M2 drivealign. We lost lock due to a 19 Hz ringup in MICH. We are not sure if this was caused by the L2P filter or if MICH is unstable. We will remeasure.
• After that we had two lockloss on the first PRMI flash. This flash is coincident with oplev damping ramping on, but we realized it is because the damping is not on before the LSC starts triggering. I moved the oplev damping to engage as "prep DRMI" in the ISC DRMI guardian, so it will hopefully help.

At this time we held in down to allow relay tube work, and used the time to measure the oplev damping and try switching to using M3 wit for lower stage damping instead.

I measured the oplev damping OLGs, pitch and yaw. The reference traces use the oplev as the sensor for the damping, and the live traces use the M3 wit as the sensor but a different matrix value that Sheila calculated based on this alog.

We then switched to M2 damping using M3 wits as the sensor, and compared the BS spectra with no lower stage damping, oplev damping, and wit damping, comparison here. We see good suppression of the modes and less sensor noise injection on the M3 wits.

Here is a screenshot of the "OLDAMP" settings we want to use on M2. I want to clarify that even though we are now using the M3 wits as the sensor, the damping is still running through the oplev damping bank on M2.

At this point, we decided to break further and allow Filiberto to update the resistors on the M1 QOSEMs, so our lockloss transient from saturation is reduced.

***

After Fil and Oli finished the sat amp changes, we began locking again. We locked PRMI with M3 wit damping engaged before the triggering occurred so there was no lockloss. Once locked, the guardian disengages the lower stage damping.

Sheila measured the BS motion using oplev and M3 wit without the L2P decoupling engaged but the wit damping off. She checked the MICH and PRCL OLGs and we saw that they were fine. MICH UGF is 8.5 Hz, PRCL is 60 Hz.

I engaged the L2P decoupling, and we saw that low frequency pitch motion was reduced. However, there was still a large 0.45 Hz peak. With the  M3 wit damping reengaged, the peak is reduced. See plot

Recipe for successful PRMI: M3 wit damping engaged, L2P decoupling engaged. Once we can reengage MICH ASC, we can turn off the M3 wit damping. I have SDFed the filters for BBSS M2 L2P decoupling 1 2

There is a lot of alignment drift in BS yaw while we sit locked. I had to touch up the aligment by hand.

We stayed in PRMI for 25 minutes.

***

We struggled to lock DRMI, and eventually chose to relock PRMI and fix the alignment. After this, DRMI locked quickly. We lost lock at the 3 f transition, so Sheila went to check we were aligned to REFLAIR 3f diodes. Then, I rephased the diodes while locked in PRMI by injecting a PRCL line and maximizing the height in 27 I, and a MICH line to maximize the height in 135 Q. PRCL, MICH, SDF

With DRMI locked, we saw that the PRCL OLG looked strange, so I also checked the REFLAIR 1f phasing. I made a minimal change to reflair 9 to improve PRCL in I and a 50 deg change in 45 to reduce SRCL in 45 Q. PRCL, SRCL, SDF

Sheila's guardian changes, to improve some problems we faced when locking.

• removed srcl mode hop offset
• if PRMI ASC flags are false, the guardian returns true (doesn't check for ASC convergence), we should also do this for DRMI ASC
• changed PRMI to DRMI transition to just zero gains for MICH and PRCL

***

Jenne and I attempted to check the PRCL/SRCL decoupling in the LSC matrix, and measured a value by injecting a PRCL line into reflair 9 and 45. However, the resulting OLGs looked even worse. Both PRCL and MICH look very strange, possibly indicating cross coupling. Unfortunately I don't have images of the PRCL transfer function but here is the MICH tf.

Seems like the phasing is wrong, but the loops became more unstable when we reverted the phasing changes I made earlier.

Wednesday OPS EVE Shift Start

TITLE: 09/09 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Commissioning
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 16mph Gusts, 9mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.11 μm/s 
QUICK SUMMARY:
The Comissioners are Working on DRMI alignment and Locking seems like H1 is going through Green Arms and IR just fine.
VAC Team is currently working on HAM7 valving.

Wed DAY Ops Summary

TITLE: 09/09 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Commissioning
INCOMING OPERATOR: Tony
SHIFT SUMMARY:

H1 Commissioning continued with relatively stable PRMI locks + 2-DRMI locks, and continued locking work (i.e. alignment tweaks, Length to Pit decoupling measurements, BS satamp whitening change, rfpd phasing, checking pointing on REFL A/B)

Relay Tube install started late morning with disassembly on HAM5 and then pumping down the Relay Tube (Gate Valves on both sides of the Relay Tube will remain  CLOSED).  Relay Tube leak checked (no leaks observed, VAC will turn OFF Mega-cleanroom at end of day)

BBSS had a satamp change to address 
LOG:

• 1522 Jenne started  on H1 to get to PRMI locking...
  • Green Arms Manual:  Green arms weren't locking, so Jenne touched up both arms by hand and they eventually locked to progress to Locking ALS; then they went to CHECK IR 
  • Had a 10min PRMI while they were running L to G coupling measurements
  • During Relay Tube work, Elenna ran OLG measurements
• 1712-1856 Relay Tube install, pump-down, & leak check (jordan, gerardo, travis)
  • --> Pumping down and maybe leak check tonight or tomorrow <--
• 1728-1847 Alog down for mainteance! (nyath)
• 1807-2012 BBSS satamp chassis change (fil)
  • 2000-2012 investigating change with oli & going out to rack
• 1813-1847 Taking photos of Dustmon pumps at EX
• 1855-1935 EX & EY glycol fill for HVAC chillers (eric)
• 1900-2000 JAC measurements (jennie)
• 1958 Vendor visit #1 (for VAC team)
• 2119-2142 Leak checking Relay Tube (jordan, gerardo)
  • No leaks for Relay Tube; Mega-Cleanroom lights turned OFF, but will turn OFF Mega-Cleanroom fans at the end of the day (to minimize temperature changes for commissioners)
• 2119-2143 EX switching off Turbo Station (travis)
• 21:42:34 Lights flickered in control room
• 2151 Vendor visit #2 (for VAC team)
• 2159 Checking alignment on REFL A/B PD on ISCT1 (sheila)
  • clicking LVEA Local on Reservation System
• 2224 sorting old tcs property for removal along the X-Beam Manifold (tj)
• 2235-2333 VAC trip to EY with vendor.

Repeating actuator calibration measurements for IMC mirrors

I tried to repeat Masayuki's measurement in this alog to calibrate the JM3, MC1, MC2 and MC3 angular motion into uradians using the IMC cavity transmission, see this alog #91487.

This injects a line in turn on each steering mirror in pitch and yaw and looks for the height of the second harmonic of this line in the IMC transmitted power, as this should depend only on the size of the dither we apply to the alignment and not any existing static mis-alignment.

 

First I paused the IMC lock guardian and then turned off the IMC WFS (take gain to 0).

I then injected a line on JM3 pitch, then JM3 yaw. There were both at 30 counts into H1:SUS-JM3_M1_TEST_P_EXC and H1:SUS-JM3_M1_TEST_Y_EXC respectively.

 

The 2f line is viisble at 22 Hz as seen in the transmitted power ASD for the pitch excitation and the yaw excitation.

I then tried to do the same for MC1. I used 17Hz as my dither frequency and checked this didn't overlap with any modes of the MC1 mirror by checking the DAMP filter bank.

I could not get good measurement coherence at 34Hz with a 30 count excitation, when I went up to 60 counts the cavity unlocked, so I turned off the excitation, unpaused the guardian and brought the mode cleaner to down.

This plot shows the ASD during the 30 count injection with the red lines marking the 1f and 2f lines.

Looking back at the ndscope for the time when I thought the IMC unlocked (the mc trans camera spot flashed), it looks like the cavity did not unlock completely but started oscillating at 1Hz.

The first cursor is when the cavity lock started oscillating and the transmitted signal on IMC-TRANS PD went from 11000 counts to 6700 counts. When I turned off the excitation it went back up to the locked level again.

Second cursor is where I purposely brought the mode cleaner to down and the IMC TRANS PD went to 4000 counts.

 

Summary: I can use a dither on JM3 to measure the calibration of this mirror but to measure the MC mirrors I need to tune my excitation more precisely.

BBSS M1 QOSEM satamp whitening modified (again)

Fil, Oli

Fil went ahead and did another modification to the BBSS M1 QOSEM satamp. This is the same modification that LLO had done (LLO:82137) - on each of the six boards, resistors R902, R1002, R1102, R903, R1003, and R1103 were swapped from 499kOhm to 22kOhm resistors.

Before the modification the satamp whitening was zpk([0.0144],[2.89],1), with compensation filter zpk([2.89],[0.0144],1). Changing these resistors has shifted the whitening zero up in frequency so the satamp whitening is now zpk([0.263],[2.89],1), with the new compensation filter zpk([2.89],[0.263],1). I have updated the whitening compensation filters ( BS_M1_OSEMINF_{F1,F2,F3,LF,RT,SD}_{SUM,X_RAW,Y_RAW} ) in OSEMINF to these new compensation filters.

Before we brought the BBSS back up we noticed that the SUM counts for F1 were railed, and that the SUMs for all other osems were between 18-20k counts. This is with the sum feedback on. When we turned the sum feedback off and just sent a constant current to the LEDs, F1 was still railed, but the other osems all jumped to normal varying SUM values that we had seen months ago prior to turning the sum feedback on - F3 and RT were staturating (like they had been doing back then), and the others were around 30k counts. Switching back to the sum feedback mode, we have been seeing the SUM counts all (except F1) climbing up slowly, and will hopefully stop in their nominal feedback on locations. We aren't sure why F1 is showing the counts as saturated though while in sum feedback mode - it hadn't been saturated before, and either way, turning on sum feedback mode should lower the current to the LED to lower the counts to a reasonable level (between 29k and 30k counts).

PSL Status Report - Weekly FAMIS

PSL Status Report - Weekly FAMIS 64006

Laser Status:
    NPRO output power is 1.86W
    AMP1 output power is 70.67W
    AMP2 output power is 139.5W
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN
    PDWD watchdog is GREEN

PMC:
    It has been locked 14 days, 3 hr 2 minutes
    Reflected power = 28.44W
    Transmitted power = 104.6W
    PowerSum = 133.0W

FSS:
    It has been locked for 0 days 0 hr and 18 min
    TPD[V] = 0.4517V

ISS:
    The diffracted power is around 4.4%
    Last saturation event was 0 days 4 hours and 22 minutes ago

Possible Issues:
    PMC reflected power is high

JAC 809Hz length dither is seen in JAC REFL camera on IOT1.

JAC REFL beam seems to be flickering in the video because the 809Hz length dither frequency is close to the integer multiple of  the video refresh rate. I disabled the 809Hz length dither momentarily and the flickering was gone, see the attached video.

If we can see the effect of the dither just by using the video like this, the length dither amplitude is probably too large to enable in observing. One omega peak observed by ISS array is huge.

HVAC Fan Vibrometers FAMIS Check (FAMIS 62540)

For FAMIS #62540: All fan trends look fairly flat (even after the step-down 5-days ago which Tony notes in alog 91811).

PSL Status Report (FAMIS #64007)

This is for FAMIS #64007.
Laser Status:
    NPRO output power is 1.846W
    AMP1 output power is 70.55W
    AMP2 output power is 139.4W
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN
    PDWD watchdog is GREEN

PMC:
    It has been locked 13 days, 21 hr 33 minutes
    Reflected power = 28.32W
    Transmitted power = 104.6W
    PowerSum = 132.9W

FSS:
    It has been locked for 0 days 9 hr and 2 min
    TPD[V] = 0.4572V

ISS:
    The diffracted power is around 4.3%
    Last saturation event was 0 days 9 hours and 52 minutes ago

Possible Issues:
    PMC reflected power is high

Wed DAY Ops Transition

TITLE: 09/09 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Commissioning
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 5mph Gusts, 2mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.13 μm/s 
QUICK SUMMARY:

Looks like great progress yesterday with X-arm opened and locking green arms.  This morning ISC LOCK is at Prep For Locking, there were multiple dust alarms, and all is fairly quiet otherwise.

We can lock ALSX with slow controls and wfs to ETMX

Camilla, Ryan S, Louis, TJ, Elenna

After GV20 was opened, we were able to successfully lock the X arm on green and send both slow control and green WFS control to ETMX!

We have rerun the baffle scripts for TMSX, ITMX, TMSY and ITMY. We have locked both arms on green, ran the green wfs, and ran through ETM_TMS_WFS_OFFLOADED. Then, we used these positions of the ITMs to set the green camera offsets. This means we can now full run the green arms initial alignment state, and no longer need to run baffle pd scripts to position the ITMs.

Camilla, TJ, Ryan and Louis worked to run the baffle scripts. They had some difficulties with ITMY because it seems to have started in a weird place, but Camilla moved ITMY around by hand enough that she was able to get the script to run properly.

From there, locking the green arms was straightforward, and there were no issues. I've attached the SDF screenshots of the new green camera offsets.

Reminder of how to do this:

1. ensure ITM alignment positions are set how you want them (either through baffle pd scripts, or full IFO alignment convergence)
2. go to END X/Y OVERVIEW and click CAM ITM PIT/YAW button to open the green camera offset screen (I included an example screenshot of the ITMX screen for reference)
3. take a 30 second average of H1:ALS-{X,Y}_CAM_ITM_{PIT,YAW}_POS channels, this is the channel next to "position", this can be done as 'z avg 30 [channel name]'
4. put that result in the "nominal" entry below "position"
5. SDF
6. Once this is set, full initial alignment should be run!

Revisit of the BBSS damping loop and some notes about issues from big kicks

Sheila suggested we adjust the top mass damping to improve the step response, 91808. I created a 20 Hz elliptical low pass so we could raise the gain even further. However, this has little effect on the 0.45 Hz ringing in the step response, because this is not coming from the top mass. This is evident in the OLTFs, see pitch below. There could be cross coupling with length, but more likely this is some pitch mode between the lower stages that is not witnessed in the top mass osems. Therefore, damping it will have to occur with a lower stage damping loop using the oplev or M3 wit.

As it stands, we're getting plenty of suppression in LPY with the top mass damping. With the updated model, 91834, we can revisit lower stage damping.

***

I wanted to add some details about a challenge we are having with the beamsplitter. In short, if the BBSS is kicked a large amount, this saturates the QOSEMs to the point that the top mass damping loops cannot be used, and we have to put the beamsplitter in safe until the suspension freely damps enough that we can reengage damping.

This happened four times today, and has happened at least twice before. The first time occured today because I was adjusting damping gains and put a gain that was so large it rung up the loop. It took about 10-15 minutes to damp down. This kick also trips the ISI.

The other three times occurred today while we were trying to lock MICH dark during initial alignment. I had put the beamsplitter into what I thought was a decent enough alignment to lock MICH dark- clearly it was not because the MICH loop engagement kicked the beamsplitter significantly. I tried twice more after touching up the alignment further and the same problem occurred. From a quick glance, it looks like the MICH and BS lock settings were correct, but I with carefully check tomorrow one more time before we try this again.

 

CDS Maintenance Summary: Tuesday 8th September 2026

WP13584,13585 Add 7th ADC to h1oaf0 IO Chassis, add to models

Erik, EJ, Jonathan, Fil, Dave:

A 7th ADC was added to h1oaf0's IO Chassis. Because all the cards in this chassis had been shifted left by one slot to move the 20bit-DAC from A1-4 to A2-1, there was only one slot ADC6 could go into, A3-4.

Erik and EJ took the opportunity of powering h1oaf0 to check the BIOS settings (some needed changing), performing Adnaco benchmark tests, and disconnecting A4 from the computer.

Fil installed the new AA chassis for ADC6, it currently does not have anything connected to its inputs.

Dave made h1iopoaf0 and h1pemcs model changes. PEM reads out all 32 channels of ADC6 into filtermodules H1:PEM-CS_ADC_6_[0-31]. These FMs have been turned on.

DAQ restart was required for the model changes.

WP13591 h1susbs add M3 matrix

Sheila, Ellena, Dave

A new h1susbs model was installed. A DAQ restart was required

WP13592 h1crsproc add BLRMS

Jim, Erik, EJ, Dave

A new h1crsproc model was installed. A DAQ restart was required

Note that the svn server redoubt was not available for a rev-lock build, so we did a "old fashioned" install

 > rtcds build h1crsproc

 > INSTALL_ONLY_REV_LOCKED=false rtcds install h1crsproc

DAQ Restart

Jonathan, Dave:

After the round of model restarts the DAQ was restarted; 0-leg followed by 1-leg. No EDC restart was required.

All framewriters rode through the restarts with no issues.

SPI P and Y Signals, Now Calibrated with QPDA Dark Noise Fixed

J. Kissel, J. Wright

Jennie and Marc did some dark noise investigations yesterday afternoon, found grounding issues, but then reverted the temporary configuration that improved the situation. 
However, this morning, mis-reading their aLOG thinking that the solution was still in place, I re-took new ASDs excited to see QPDA fixed.
Even though their temporary solution has been reverted, QPDA still seems to be fixed. 

So -- here's some excellent, final answer plots for pitch and yaw, comparing HAM2 and HAM3 rotation against their local sensors.

PITCH
    - Now, as expected, the whitened ADC noise QPDA aka ISIK's HAM3 sensor is the factor of ~5x larger where the QPD is limited by ADC noise above 0.5 Hz, and it has the same inverse-whitening-filter shape as QPDB.
    - Encouragingly, the QPDA ISIK optical lever PIT signal matches the HAM3 CRS RY signal below 0.5 Hz -- so this QPD will be at least a little bit useful!
    - The noise floor of the QPDA ISIK optical lever PIT signal is better than the CRS above ~2 Hz, though the actual platform motion (as reported by the GS13s) is still much lower than that.

    Very interesting science -- 
    - The improvement in platform motion of HAM3 from blending in the CRS is corroborated with the ISIK optical lever signal below 0.5 Hz.
    - The QPDB measure of HAM2 shows that there's a lot more physical motion in PIT in the 1 to 10 Hz region than is reported by the in-loop GS13s. In that region, the QPD's signal is a factor of 10 above the noise floor, so I'm pretty sure this is real signal.

YAW 
    - Again, the two SPI QPDs noise floor now makes sense, with the QPDB (on HAM3) measurement of HAM2 (ISIJ) noise floor being a factor of ~5x better than the QPDA (on HAM2) measurement of HAM3 (ISIK).
    - Thus, the SPI OL YAW measure of HAM2 agrees with the local HAM2 sensors up to ~0.8 Hz, but the OL YAW measure of HAM3 only agrees up to 0.5 Hz.


Measurement time: 2026-09-04 16:47 UTC. I took 25 averages with a 0.01 Hz frequency resolution. Hanning window with 50% overlap.

ISIs were isolated, IMC was locked, still no IFO tho. sensor correction was ON in the nominal WINDY configuration. No earthquakes. CRS is blended in with ISI HAM3.
Spots centered, nominal sum voltage.

DTT Calibration of traces beyond what's done in the front-end is what's quoted in LHO:91809, namely -- just a conversion of nanoradians to radians for sensors already in displacement, and converting the GS13s from inertial sensor units asymptoting to 1 [nm/s] into displacement by inverting the ideal 1 Hz pendulum response. 

Calibration of JAC error signal into m

I wanted to get a rough number for the JAC error signal in Hz, this it to allow Jeff and I to measure the frequency noise of the JAC as an independent monitor of the IMC frequency noise which will allow us to compare the IMC length noise to the SPI length noise.

I think Masayuki calculated this back in March LHO alog #89399  but I wanted to recheck it as the Guardian settings have been changed since then.

I measured the unlocked error signal Vpp at H1:JAC-L_SERVO_IN1_DQ to be 1.01365V.

The value in metres is the half-width at half-maximum of the cavity.

First calculate the HWHM in Hz:

HWHM = FSR/2*Finesse  = 0.595 MHz.

The finesse was measured by Masdayuki and I at Caltech for our JAC which is unit 008 (see E2500324).

The FSR of the JAC I got from T0900616 to be 148.5MHz (couldn't find the exact FSR for this specific unit mentioned anywhere so used the one quoted in the PMC design document).

This means to measure the frequency noise we need to multiply the signal at 

H1:JAC-L_SERVO_IN1_DQ by 0.587 e6Hz/V to measure frequency noise.

 

SPI Readout vs. ISI Sensors: A First Comparison

After the angle calibrations were applied to the SPI readout channels, I grabbed some data to check whether the SPI is roughly agreeing with the ISI sensors. I used the supersensor OUT channels for the ISI sensors (these are the signals behind the blending filters, before the summation for the blended supersensor). Screenshots from diaggui are attached.

For the differential X degree of freedom (SPI length), the visual agreement is remarkably good.

The optical lever (angle) measurements are harder to interpret. First of all, QPD A has an as-yet-unresolved noise issue, which Jennie is currently investigating. Aside from this, the results look very encouraging, since the CPS and GS13 at least somewhat agree with the SPI.

These spectra should be regarded as a first result, but not yet final. We will post a better analysis once the error has been resolved.

Note: If anyone has suggestions for which sensor channels would provide a better/more appropriate comparison than the supersensor OUT channels used here, please comment, your input is welcome.