Travis, Gerardo, Jordan, Betsy, Tyler, Richard

This morning we proceeded with the manual opening of GV20. Tyler had made a nice support for the input shaft on the gearbox to stabilize it while rotating the handwheel. This worked great, no additional oil leaked out of the gearbox after installation.

We had left the valve soft closed overnight, so we started raising the valve at 10:41:59 Pacific by turning the handwheel counter clockwise, stopping every 50 turns to check the ballnut/shaft collar gap. No issues found.

At turn 370, we tested to see if the handwheel would be driven backwards by the weight of the gate. No backwheeling was present, so we continued raising the valve stopping every 50 turns to check ballnut/ball screw height. At turn 620 we decided to increase the interval between stoppages to 100 turns. After turn 1520, the top of the ball screw was about even with the top of the clutch body. At 1920, there was enough exposed ball screw to install the safety plate and the locking collars. Locking collars were torqued to 140 in-lbs. 

We then continued raising the valve 300 turns (2") at a time, adjusting the lock collars at each interval, until the medm screen showed green.

Final turn count: 7167

Final ball screw height, +37.75" from top of clutch body (open position/green on medm) Note: Height stamped on side actuator body read 37 7/8" for the open position.

The interlock pin was then set, and lock collars were moved to top of safety plate, and torqued to 140 in-lbs. The handwheel was left installed on the gearbox with a clamp on it to prevent rotation.

Full set of compiled notes/details will be posted to the DCC with noises/turn counts/timestamps/ball screw heights/etc.  

Jim, Arnaud

wp 13661

We replaced the temporary CRS laser driver with the final version D1500207 (and PCB D1200719-v11) and commissioned the TEC loop. The AC powered Thorlabs TEC is now unplugged from the TCS-R2 rack.

In order of operation: 

• Took the Laser Chassis hosting the RIO Laser to the EE lab, and added screws and thermal paste between the Laser Diode and the butterfly mount, as recommended in section 7.4.2 of the laser user manual (E2600086). 
• Reconnected the Laser Chassis and verified we could still get the same power (and noise) with the temporary setup.
• Swapped the Laser Driver with the new one, still using the Thorlabs TEC and verified we could get to the same power as with the temporary driver. The knob must now be set at 8.5 to reach the max power.
• Turned off the drive to the laser, and commissioned the TEC loop, with the same settings as in 1053. The figure attached (fig1) shows the thermistor readback following the error point request. 
• After reaching stable temperature, we turned the laser back on and verified the hoqi power and noise was the same as before. Will leave in this state for tonight

To note, the plexiglass key protector was mounted in front of the wrong chassis (Laser Chassis instead of Laser Driver, which controls the state of the laser). We swapped it, so it matches the laser SOP. 

TITLE: 09/30 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 9mph Gusts, 5mph 3min avg
    Primary useism: 0.09 μm/s
    Secondary useism: 0.15 μm/s 
QUICK SUMMARY:

The XARM is open, there is now a full IFO to work with!

• 23:45 UTC SUSAUXBH234 model restart
• 23:57 UTC GV20 open
  • 00:21 GV19 soft open
  • 00:24 UTC GV19 open
• I started to run the baffle align GRD states before realizing that the ALS laser was not on... 
• The MSR racks temperatures have been rising over the past 12 hours                                                                                                                                                                                                                 

Updating the PCAL Epics variables based on the last few End station measurements. 

Suggested Epics values for H1: 
 

caput H1:CAL-PCALX_FORCE_COEFF_RHO_T 8301.33
Old : H1:CAL-PCALX_FORCE_COEFF_RHO_T 8300
New : H1:CAL-PCALX_FORCE_COEFF_RHO_T 8301.33
caput H1:CAL-PCALX_FORCE_COEFF_RHO_R 10721.3
Old : H1:CAL-PCALX_FORCE_COEFF_RHO_R 10713.3
New : H1:CAL-PCALX_FORCE_COEFF_RHO_R 10721.3
caput H1:CAL-PCALX_FORCE_COEFF_TX_PD_ADC_BG 9.46843
Old : H1:CAL-PCALX_FORCE_COEFF_TX_PD_ADC_BG 8.81815
New : H1:CAL-PCALX_FORCE_COEFF_TX_PD_ADC_BG 9.46843
caput H1:CAL-PCALX_FORCE_COEFF_RX_PD_ADC_BG 0.574209
Old : H1:CAL-PCALX_FORCE_COEFF_RX_PD_ADC_BG 0.56678
New : H1:CAL-PCALX_FORCE_COEFF_RX_PD_ADC_BG 0.574209
caput H1:CAL-PCALX_FORCE_COEFF_TX_OPT_EFF_CORR 0.987685
Old : H1:CAL-PCALX_FORCE_COEFF_TX_OPT_EFF_CORR 0.99331
New : H1:CAL-PCALX_FORCE_COEFF_TX_OPT_EFF_CORR 0.987685
caput H1:CAL-PCALX_FORCE_COEFF_RX_OPT_EFF_CORR 0.989862
Old : H1:CAL-PCALX_FORCE_COEFF_RX_OPT_EFF_CORR 0.9944
New : H1:CAL-PCALX_FORCE_COEFF_RX_OPT_EFF_CORR 0.989862
caput H1:CAL-PCALX_XY_COMPARE_CORR_FACT 1
Old : H1:CAL-PCALX_XY_COMPARE_CORR_FACT 0.99855
New : H1:CAL-PCALX_XY_COMPARE_CORR_FACT 1
caput H1:CAL-PCALY_FORCE_COEFF_RHO_T 7146.49
Old : H1:CAL-PCALY_FORCE_COEFF_RHO_T 7155.15
New : H1:CAL-PCALY_FORCE_COEFF_RHO_T 7146.49
caput H1:CAL-PCALY_FORCE_COEFF_RHO_R 10659.1
Old : H1:CAL-PCALY_FORCE_COEFF_RHO_R 10663.6
New : H1:CAL-PCALY_FORCE_COEFF_RHO_R 10659.1
caput H1:CAL-PCALY_FORCE_COEFF_TX_PD_ADC_BG 18.5852
Old : H1:CAL-PCALY_FORCE_COEFF_TX_PD_ADC_BG 18.3088
New : H1:CAL-PCALY_FORCE_COEFF_TX_PD_ADC_BG 18.5852
caput H1:CAL-PCALY_FORCE_COEFF_RX_PD_ADC_BG -0.635276
Old : H1:CAL-PCALY_FORCE_COEFF_RX_PD_ADC_BG -0.7353
New : H1:CAL-PCALY_FORCE_COEFF_RX_PD_ADC_BG -0.635276
caput H1:CAL-PCALY_FORCE_COEFF_TX_OPT_EFF_CORR 0.983803
Old : H1:CAL-PCALY_FORCE_COEFF_TX_OPT_EFF_CORR 0.99191
New : H1:CAL-PCALY_FORCE_COEFF_TX_OPT_EFF_CORR 0.983803
caput H1:CAL-PCALY_FORCE_COEFF_RX_OPT_EFF_CORR 0.986169
Old : H1:CAL-PCALY_FORCE_COEFF_RX_OPT_EFF_CORR 0.9931
New : H1:CAL-PCALY_FORCE_COEFF_RX_OPT_EFF_CORR 0.986169
caput H1:CAL-PCALY_XY_COMPARE_CORR_FACT 1
Old : H1:CAL-PCALY_XY_COMPARE_CORR_FACT 1.00092
New : H1:CAL-PCALY_XY_COMPARE_CORR_FACT 1

TITLE: 09/30 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY:

GV20 work took place most of the day (and the thought is they may get it open today).

Other work:  OMC scans, HAM2 SEI troubleshooting, CRS work, etc.
LOG:

• 1430-2125 crack sealing on x-arm road (randy)
• 1522-1800 OMC scans with SQZ beam after OM2 heating (camilla, sheila, ryanS)
• 1548-1607 technical cleaning @optics lab (kim)
• 1603 GV20 prep @EX (jordan, gerardo)
• 1613-1630 Dropping stuff into recycling outside HiBay (christina)
• 1637 GV20 (travis.betsy)
  • Richard also made a trip out there back at 1924
• 1646 GV20 (tyler)
• 1738-1747 tcs chiller check (corey)
• 1750-1858 troubleshoot AI chassis channel for HAM2 SEI (jim.arnaud WP13669)
  • 1828 HAM2 ISI tripped
  • Overheard Jim tweaking CRS when he got back from CER.
• 1818 Apollo visitor (contacted bubba to connect with him)
• 1819-1848 PCal Lab (tony, caroline)
• 1832-1855 MY parts for storage (ryanC)
• 2042 Return to GV20 (travis,gerardo,jordan,betsy)
  • Saw tyler making a trip to EX at the end of the shift.
• 2056 CRS work at TCS/CRS rack (jim,arnaud)
• 2120-2211 SGN group tour in control room and roof
• 2145 checking on GV20 status at EX (richard)
• 2158-2210 Checking on LVEA wind sensor (it's busted! Fil will replace it on a future cool morning.) [dave]
• 2203-2227 CHETA Lab work (camilla.sophie)

Following up on the corner station wind speed going quiet following Friday's wind storm, a quick inspection showed that the anemometer support has broken off and the unit is dangling by its cable at the base of the weather station.

If you look very closely at the photo you can see the swam of flying ants around the weather station which makes working in this area very uncomfortable.

Jennie W

I tried to measure the SPI diff CPS and GS13 monitor channels to compare them to the SPI sensor, I noticed that the GS13 Y and Z DOFs plus the X GS13 and CPS DOFs did not have their gains set to 1 or their outputs were not switched on.

I have fixed this and accepted it in SDF for seiproc.

Yesterday I took several beam profiles of the SQZ beam on SQZT7 using the ThorLabs M² device at various settings for the ZM4 and ZM5 psams as we've done in the past to create a "grid" of values. The psam strain gauge values chosen for this set of measurements was:

ZM4 = [-3.5, -1.5, 0.5, 3.0], ZM5 = [-9.3, -7.0, -5.0, -1.3]

Between Sheila, Camilla, and myself, we were able to produce the attached figures comparing these profile results with the OMC scans taken last week (alog92065) to show the predicted mode mismatch between the SQZ beam and the OMC. The results indicate running on the very low end of the psams range with both ZM4 and ZM5 gives the best mode matching into the OMC with the current ZM2 setting.

EDIT: Fixed some parameters in the code that makes the attached plots so they're more accurate; re-ran and reuploaded here.

Ryan S, Sheila, Sophie, Camilla 

Repeated SQZ to OMC scans in 92065, now with OM2 hot 92106, thermistor 1 is still changing plot, but the heater has been on for 16 hours has changed from 22deg to 32deg, in the past it has leveled out at 33deg so is >90% of the way there. 

Re-touched up OM3/OMC alignment with OMC locked on 00 mode to get misalignment peak <0.5% (plot), saved to /sqz/h1/Templates/dtt/OMC_SCANS/Sept30_2026_OMC_scan.xml

The ran scans with /ligo/gitcommon/squeezing/sqzutils/sqz_to_OMC_mode_matching/omc_scans_sweep_psams.py

PSAM_VALUES_V5 = [-9.3, -7, -5, -1.3] 
PSAM_VALUES_V4 = [-3.5, -1.5, 0.5, 3.0] 

Interestingly the powers today plot on all diodes in HAM6 a 2-5% higher than last week plot. Unsure if this is caused by OM2 hot or a slightly different FC alignment.

OMC scan plot attached. SQZ to OMC mode matching is worse with hot OM2.

Plots of this with Ryans M2MS data from Monday 92103 propagated with hot OM2 ROC of 1.75m attached. Ryan and Sheila temporarily OM2 ROC edited in it the lho_O4.yaml. Hot 1.75m value from 84255 where cold OM2 ROC is 2.1m.

• Scatter Plot
• Stem Plot
• Contour Plot

We are going to cool of OM2 now. 

Addressed TCS Chillers (Wed [sep30] 1038-1047am local time) & CLOSED FAMIS #85358.

For measurements below, measuring from "top" of the red floaty ball.

• TCSx Chiller:  Had level of 30.5 cm.  Added 0mL for 30.5cm.
• TCSy Chiller:  Had level of 10.6 cm.  Added 0mL for 10.6cm.  
• There was no water in the small cup under the slow leak. (but happened to notice a gooey liquid under the cup).

offline from 10:53 PT while Jim and Fil troubleshoot AI issues wp 13669, alog 92116

I redid the measurement of the SPI QPD A that I did in LHO alog #92050. I had been comparing ASC-AS_C_NSUM_OUT_DQ which is calibrated in W at the anit-symmetric port with the individual sum channel of SPI-OL_H23_QPD_A_SUM_OUT_DQ which is in V/V as it is normlaised by the sum of the four segments.

As this measurement is using data from the 22nd, the only DQ'd channels I could compare between the two QPDs are the PIT_OUT_DQ and YAW_OUT_DQ, which are all in V/V.

The measurement shows there is ony coherence between the pitch at the ASC-AS_C QPD and the pitch of SPI QPD A.

The coherence level is 0.6 at 1Hz and drops to near 0 below 0.2 Hz this and above 4Hz.

The transfer function from anti-symmetric port to QPD A has a level of ~7e-6 V/V and a phase of 170 degrees at 1Hz.

This will hopefully have a very small effect on the QPDA and so might not be as much of a problem as I had thought from my previous entry.

J. Kissel, J. Warner
WP:13657

As we starting working through comparisons of SPIH23 with the first instantiation of real-time differential signals computed in the seiproc model with on-board ISIHAM2 and ISIHAM3 sensors, we realized that 
    (a) We should remove a layer of confusion and use the sensor-corrected, "inertial" CPS, rather than the un-corrected CPS. Otherwise, the local "input to the blends" and thus the local super sensor will disagree with the seiproc re-construction as shown in LHO:91990 and LHO:92026; and 
    (b) We're getting greedy in trying to re-create a super-sensor that combines the local GS13s and CPS with a re-production of the blend filters, and then subtracts -- all so we "just" have one trace to compare to SPI signals. However, to reduce computational complexity and signal calibration confusion, we should create a back-up "good enough" solution and do what we did during the SPI conceptual design phase (see LHO:83412).

So, yesterday, with the help of Dave (LHO:92104), we installed two changes to the seiproc calculation of (HAM3) - (HAM2) = "H23" and (HAM4) - (HAM5) = "H45" signals.
    (1) The change that "fixes" (a), we mapped the sensor corrected CPSs from the ISIHAM2, ISIHAM3, ISIHAM4, and ISIHAM5 models to seiproc, rather than the "raw" CPS.
    (2) We built up parallel infrastructure to the blended super sensor reconstruction that "just" subtracts (HAM{3,4} - HAM{2,5}) GS13s and (HAM{3,4} - HAM{2,5}) GS13s, and (HAM{3,4} - HAM{2,5}) CPS and (HAM{3,4} - HAM{2,5}) CPS. No blends, no calibration, just straight subtraction. 

The output of the matrix that does the subtraction (2) is fed into filter banks, where -- for now -- only the Y and Z degrees of freedom have an optional "to_nrad" (from [nm]) filter that divides the differential signal by 15.4 [m], i.e. a gain of 0.064935 [1/m].

The MEDM GUI is still under construction, but I've got enough of it functioning that you can see the system:
    . Screenshot 1
        The beginnings of the ISI DIFF overview screen. This is linked from the SITEMAP via the pink SPI menu.
        On the left is all of the input signals (the seiproc version) from each of the HAMs' CPS (in shades of BLUE) and GS13s (in shades of GREEN).
        Again, now the incoming CPS are the sensor-corrected CPS.
        At the top middle is the infrastructure that was already in place to blend the CPS and GS13s together.
        At the bottom middle, there was only one matrix to subtract the reconstructed super sensor, but now there're two more matrices to subtract the CPSs and GS13s independently, respectively.
        Finally, again where there was only one set of filters to filter the reconstructed super sensor, now there's two more sets of filter banks to independently calibrate or at least unit convert the differential CPSs and differential GS13s.

    . Screenshot 2
        A shot of the differential CPS matrix, with visual aides drawn on for now (I'll add these labels to the screens themselves in due time).

    . Screenshot 3
        A shot of the differential CPS output filter banks, with the "to_nrad" filter shown turned ON in the Y and Z banks.
  
    . Screenshot 4
        A shot of the blend filters for the X DOF of HAM2, just to give folks the impression of what's going on here.
        All of these filters haven't changed since Jim validated that he copied the over from the local ISI models with good fidelity (see LHO:92054).

I've turned ON the infrastructure as shown, and accepted those values as "ON" into the SDF system.

So -- if you're looking to use these channels, here they are explicitly:
    (I) Differential CPS (in [nm] or [nrad]): 
        H1:ISI-DIFF_H23_DIFF_CPS_{X,Y,Z,RX,RY,RZ}_OUT_DQ
        
        NOTE: This is different and separate from the existing "CPS DIFF" channels, e.g. ISI-DIFF_HAM2_CPS_X -- as these channels are each chamber subracted from *the ISI BS* CPS. Hence the unfortunate new channel "feature" of having DIFF twice in the channel name.


    (II) Differential GS13 (in inertial sensor units, asymptotes to 1 [nm/s] or 1 [nrad/s]): 
        H1:ISI-DIFF_H23_DIFF_GS13_{X,Y,Z,RX,RY,RZ}_OUT_DQ

    (III) Pre-subraction, blended, re-constructed super sensor for each chamber (test points, not filter banks; in [nm] or [nrad]):
        H1:ISI-DIFF_{H2,H3}_BLND_SS_{X,Y,Z,RX,RY,RZ}_DQ

    (IV) Differential Super Sensor (in [nm] or [nrad]):
        H1:ISI-DIFF_H23_SS_{X,Y,Z,RX,RY,RZ}_OUT_DQ

Again -- for the time being -- the Y and Z channels are calibrated into [nrad] of (differential Y) / L and (differential Z) / L so they can be directly compared with SPI optical lever YAW and PIT signals, respectively, directly.

May it all make sense now! #crossesfingers
    

Summary: In switching QOSEM whitening gains from the 1st to 2nd modification, there has been a slight increase in noise in the P and Y DOFs, all others uneffected. Whitening gain should be increased again by a factor of 2-3x.

This is one in a series of posts investigating the excess noise seen on the BBSS M1 QOSEMs. In short, at both LHO and LLO, the noisefloor of the QOSEMs appears to be around 8pm/rtHz at 100Hz, quickly increasing to 50pm/rtHz by 1Hz; where we expect the noisefloor to be flat at ~5pm/rtHz across this bandwidth. See more details in LHO alog 91466. 

Below in Figure 1, we plot QOSEM readout spectrums when the sat amp was configured with the 1st and 2nd modifications of whitening gain, as described in LHO:91998. The 1st modification dataset was taken from T0:1470725000, during which BBSS M1 damping was on. The 2nd modification dataset was taken from T0:1474137198, during which BBSS M1 damping was off, explaining the additional peaks seen in 2nd modification dataset.

This shows that the reduced whitening gain has not significantly impacted the QOSEM noisefloor, and further rules it out as the source of the excess noise. There is a slight increase in noisefloor in the pitch and yaw DOFs in the 2nd modification whitening, so there is a case that whitening is insufficient and should be increasing by a small margin again, perhaps a factor of 2-3x or so. 

Travis, Gerardo, Jordan, Betsy, Tyler, Richard

This afternoon we began the process for opening GV20, following the procedure outlined in E2600314.

To prep, Tyler machined a 7/8" hole in the 8" diameter handwheel so we could drive the gearbox by hand. We then closed GV19, measuring the distance from the top of the clutch body to the top of the ball screw in the open and closed positions. 

Open: +37 9/16"  Closed: -10 5/16" (zero is the top of the clutch body)

Moving on to GV20, the motor had been decoupled from the gearbox yesterday, so we again confirmed the measurement from the top of the ball screw to the clutch body with the valve closed. 

Closed: -10.125" (zero is the top of the clutch body).

Then we torqued the loose set screws on the top clutch retaining nut. We confirmed there was only 1 set screw per hole, but they were not brass tipped set screws as expected.

We then proceeded to check the set screws on the drive shaft collar/ball nut. We had to rotate the drive shaft in order to access to these set screws, so we began turning the handwheel clockwise, per procedure at 1:48:40 Pacific. There was some increased resistance after~20 turns, and then at turn 31 the clutch popped (1:56pm Pacific). We stopped and called Jon F to discuss. We re-measured the ball screw position and found it at -10 5/16", so the ball screw had been driven down and that's what popped the clutch. We then turned the hand wheel counter clockwise with a scale on the ball screw and confirmed it was indeed raising. After 15 turns, the clutch reset and then at turn 31 (net 0) we stopped and re-measured the ball screw and it had returned to -10 1/8". We then checked the ballnut and confirmed no threads had been exposed. 

We then met with the rest of the group on Zoom to discuss before proceeding with the rest of the procedure. We decided to continue raising the valve until we could check the set screws on the drive shaft collar, then raise it 1" past the point where the valve un-cams then set it back down 1" to confirm operation and rotation is as expected.

So we continued raising the valve by turning the handwheel counterclockwise, stopping every 50 turns to inspect the ballnut and measure the height of the ballscrew to confirm it was raising. At turn 171 (3:22 pm) the valve state turned from red to yellow on the medm screen. We used this as the point of "soft close". The ball screw height was exactly -9" at this point. We noticed a small amount of oil dripping from the gearbox during raising. We then continued raising for the 1" test after turn 171 (expected 150 turns per inch, so 321 turns total) again stopping every 50 turns to check the ballnut. When stopping rotation of the handwheel, it rotate slowly backwards (clockwise), but would stop after varying fractions of a turn (maximum was ~1/2 turn, with caveat that I never fully released to wheel, so I could stop rotation if needed).

Once we got to turn 321 (3:37:40 Pacific), we stopped, checked the ballnut and measured the ball screw height of exactly -8". We then lowered the valve by turning the handwheel clockwise back 150 turns (3:49:00 Pacific), where it will remain overnight. By this time more oil had dripped from the gearbox, we put a foil tray underneath to collect any oil that may come out overnight. Pictures below are of the oil at the end of the day, after lowering the valve back to soft close position.

We will meet with the group tomorrow morning to decide the next steps.