TITLE: 08/28 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

At the  begining of the shift ETMy ESD was being restored and then this allowed Commissioners to work on locking (since ETMx is finicky, they were working on using ETMy (which has its own problems) for ALS DIFF---see Elenna/Louis alogs.
LOG:

• 2342-0118 Started Locking work (elenna, louis, sheila)
  • ISC_LOCK taken to GREEN ARMS MANUAL--->ALSy made it to ETM TMS WFS OFFLOADED ( they started locking after they turned Sheila/Marc turned ON the ETMy ESD at EY...Sheila said they probably could have turned it on from the Corner)
    • Due to ETMx, ALSx only went to LOCKING
    • Worked on ALS DIFF with ETMy (which has the issue of a bad quadrant)
• 2347 DONE:  Tour for SRS visitors (mike,daniel)
• 2349 DONE:  EX grounding studies (robert)
• 2352 DONE:  Checking ESD at EY (sheila, marc)

Oli, Elenna

Today, we tried to balance the coils on the BBSS M2 and M3 stages. I chose to use AS_C as an optical lever, since we have previously observed some strange cross coupling on the BBSS oplev and I didn't want to get confused.

Coil balancing steps:

• I put IFO in single bounce off ITMY with 10 W input power
• I centered the beam on AS_C by running SR2_ALIGN in the ALIGN_IFO guardian
• For M2, I changed the length euler to osem matrix to drive a pringle mode, so I made the UR and LL matrix values negative, while leaving UL and LR positive. Then, I drove a beamsplitter length line at 8.125 Hz from M2 test
• I observed the 8.125 Hz peak in AS_C pitch and yaw and adjusted the coiloutf filter bank gains to minimize the line height. I ensured that the absolute value of the gains still summed to 4 during my changes
• Then, I reset the M2 matrix, repeated the same process for M3

I was able to get a 20 dB reduction in pitch and yaw on M2, but only a decent pitch reduction on M3. I should revisit the M3 measurement again, since I was just guessing which way to go with the gains, and there is probably a much more procedural way to go about this.

Bs M2 shows the improvement in pitch and yaw and the final gains.

BS M3 shows the improvement in pitch and little improvement in yaw, also final gains.

I SDFed these coil gains (91735)

I had previously measured the L2P and L2Y coupling on M2 and M3 before balancing the coils. I remeasured the transfer functions afterwards, again using single bounce to AS_C. There was only a significant difference in the M3 L2Y coupling- I was unable to measure it at all, despite using the same drive as before. I couldn't bump up the measurement drive since I was close to falling off AS_C.

I have attached screenshots of each measurement. The blue reference traces are from before the coil balancing.

I will fit these measurements and implement them in the drivealign matrices. Then, we can check the decoupling of the L2A during PRMI/DRMI locking.

Here are some SDFs of BS, ASC, and LSC before SDF revert today.

FAMIS task complete, started both systems at end stations, left the compressor and dryer units run for 2.5 hours each, found a couple of air leaks, fixed the leaks and the dew point for both systems look good.

Posting some initial plots of SPI DIFF L, doing my best to line up with my results here with alog 73976, where Jeff looks at IMC F length in hz/rthz and compares that to ISI motion. On the attached image, I show spectra for the differential HAM2-3 X super sensors (calculated online in seiproc, using blended cps and gs13s from each chamber), HAM2 and 3 X gs13s and IMC F, all calibrated to hz/rthz using Jeff's factors from 73976. H1:SPI-H23_DIFFDISP_MAIN_OUT_DQ is also calibrated to hz/rthz using the same 70.551 hz/nm Jeff calculated for the ISI. With that calibration, SPI DIFFDISP is still off from the other sensors by about a factor of 3. 

For the second image, I made a new copy of Jeff's template from 2023, re ran it for last night and added SPI DIFFDISP. We don't have CARM yet, so it's not complete, but I updated references. Again, I used Jeff's 70.551 calibration factor to convert SPI DIFFDISP from nm to hz. SPI seems to agree better here, so I'm not sure what the differences are from from first plot. 

Since we were going through sdf revert today I accepted some JAC ASCIMC and LSC model diffs. See first two images.

The next image is some slow controls settings we want to stay constant when the Bekchoff computer restarts. I didn't accept the pole value as I am still making changes to the heater servo this pertains to.

The last picture shows that i unmonitored the input switch, FM1 and FM2 switches on the JAC-L_SERVO filter bank. These are switched on by the guardian when we lock the JAC so we don't want the JAC to unlock when we sdf revert (as happened today before I made this change to the sdf monitor).

Jennie W,

Last night I added a second pole to the JAC controller with the view to increasing the damping. It has not helped (JAC temperature is still oscillating after ~20 hours).

This is no improvement on how long it took to damp when we increased the set power of the JAC on Tuesday 18th alog #91587.

After thinking about it a bit more and comparing the temperature stability before and after I increased the gain magnitude of the servo (also on Tuesday 18th), I think our gain is too high and causing the system to oscillate.

I think the order of operations over the weekend is to remove the second pole, turn down the gain and then set up the guardian node to add in the PZT feedback signal to the heater controller error point. I will test this over the weekend when it won't affect corner commissioning.

TITLE: 08/28 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Corey
SHIFT SUMMARY:

• Started out doing some clipping investigations in single bounce and SR2 AS_C centering on - 91727
• Locked PRMI, maximized by hand, then Louis started spot measuring on PRM, then OLGs on MICH, PRCL - 91726 , 91724
• BS osem calibrations
• PRMI locking but with ALS locked off resonance
  • To get here we went through SDF revert after checking SDFs first

LOG:

I've made plots comparing the M1 stage BSFM BOSEM noise to the BBSS QOSEM noise to see how much better we are. This is similar to the plots TJ O made in 91466. During the time the BBSS data was taken from, we did have the LED sum current feedback switched on, but comparing our BBSS QOSEM noise to the two QOSEM noise floor plots (taken from G2501105 slide 29), it really looks like we are currently being limited by the constant LED current, as if we didn't have the feedback on at all.

We know the sum current feedback loops are doing something because when we first turned them on, they adjusted the sum counts on two of the osems that were reading too high of counts, but based on these plots it doesn't look like they're doing much? TJ O and I will talk with Tom to investigate more.

Results:
/ligo/svncommon/SusSVN/sus/trunk/BBSS/H1/BS/SAGM1/Results/2026-07_OLG_tfs_4_BSFMvsBBSS/allDampRegressCompare_H1SUSBSFMvsBBSS_M1_NoiseComparison_1435435038vs1469227619-1200.pdf
r13134

Loop suppression used to divide out:
BBSS: /ligo/svncommon/SusSVN/sus/trunk/BBSS/H1/BS/SAGM1/Data/Data/2026-07_OLG_tfs_4_BSFMvsBBSS/2026-07_H1SUSBS_M1_CDBIOState1_WhiteNoise_{L,T,V,R,P,Y}_0p02to50Hz_OLGTF.xml
BSFM: /ligo/svncommon/SusSVN/sus/trunk/BSFM/H1/BS/SAGM1/Data/2023-07-18_1740_H1SUSBS_M1_CDBIOState_1_OLDampingON_WhiteNoise_{L,T,V,R,P,Y}_0p01to50Hz_OpenLoopGainTF.xml

In an attempt to look for obvious clipping in the PRC, I scanned around +/-150 urads from our PR3 alignment while in single bounce and with SR2 following along to keep AS_C centered. This was a painfully slow process as I would move PR3 until SRC2 would near its limiters, wait for it to settle down, then move again. I ended up bumped the SRC2 gains way up to help speed this up, but it only helped a bit. 

I saw no signs of clipping in the +/-150 range, so I continued in yaw until AS_C nsum finally started to decrease. This didn't happen until +500urad in Y from our starting point. We stopped here to run some more pertinent tests. I reverted all alignments back to before this test.

At Sheila's suggestion this morning I measured the beam spot position on PRM in PRMI. The drivealign gains that reduce the A2L coupling are P:0.38, Y:0.81. I used the same procedure as in 91701. This corresponds to an offset from center of 0.713 mm in PIT and 1.52 mm in YAW.

Here are MICH and PRCL OLGs from today while in PRMI.

TITLE: 08/28 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 7mph Gusts, 3mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.10 μm/s 
QUICK SUMMARY: No alarms, calm environment. The EX VEA temperature has been moving around quite a bit the last few days. Looks like this was from the cleanroom being turned on.

TITLE: 08/27 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

Commissoiners (Elenna, Louis, Camilla) were working on H1.  Once they were done, I let Jim know so he could run SPI injections on HAM2 & HAM3 over night.

LOG:

• continued from day:  Commissioners working on H1
• 2350 Commissioners DONE for the night.  (JAC & IMC @LOCKED.  ISC_LOCK @IDLE)
• 2355 Notified Jim he is OK to GO for HAM2+3 SPI injections.
• 0021 Tuning JAC temperature servo (jennie)
• 0029 Seismic to MAINTENANCE
• 0050 EX grounding studies done for the day (robert)

[Elenna, Sheila, Louis, Keita, + input from others in CR]

This log is for work done yesterday August 26, 2026.

Yesterday we set out to move the beam spot position on PR2 with a dither line to determine whether the current beam spot position is the same as it was during O4. This test is part of the same line of investigation mentioned in 91701. The idea is that if the beam is still at the O4 spot position on PR2 then moving the beam in pit or yaw should result in higher A2L coupling than you would get at the nominal position. This test was done in PRMI. 

We had to pause midway and rethink the execution of this test because we kept losing PRMI lock. 

We used the guardian state PR2_SPOT_MOVE to move the beam spot position on PR2 while monitoring the A2L coupling using a dither on PR2's M3 DITHER bank (8.125 Hz, same as before). The guardian state lets us move the PR3 sliders and it will move IM4 and PR2 to compensate. 

Since this move has downstream effects in the POP path, Elenna held the output on POPAIR RF18_I, which provides the trigger signal for PRCL and MICH. We started off going in the +Yaw direction in steps of 0.3 urad using the PR3 slider. We noticed that each move would kick the MICH and PRCL loops. I was only able to move about 2 urad before losing PRMI. This was repeatable: I lost lock after moving 2.7 urad (yaw slider value -234.0) and later after only moving 2.4 urad (PR3 slider value -234.3). The nominal slider values for PR3 at the start of this test is Yaw: -236.7, Pit:-142.7. 

We considered that we could be falling off of the REFLAIR diode during these moves. REFLAIR_A_RF9_I and REFLAIR_A_RF45_Q are used as the input signals for PRCL and MICH, respectively. Interestingly, we noted that as we continued to move in the +yaw direction the demod diodes would see a small kick while the DC signal (REFLAIR_A_LF) was increasing (ndscope screenshot). This was repeatable and doesn't make sense to me right now. Meanwhile, we were losing power on POPAIR 18 and 90 (not surprising) and on POPX (not surprising). We turned off the DC centering for POPX because PM1 starts to rail pretty quickly if you don't. 

After losing lock a couple of times Elenna suspected that something weird might be happening with the MICH and/or PRCL loops. So she measured the OLGs while I moved the beam spot position on PR2. I've uploaded DTT screenshots of the MICH OLG and PRCL OLG. Both of these OLGs were taken after moving and pausing 2.1 urad away from the nominal position on the PR3 sliders (PR3 slider yaw: -234.6). 

The PRCL OLG looks to have experienced a loss in gain. We tried compensating by increasing the gain, but this didn't help avoid losing lock. The MICH OLG measurement showed some more egregious changes that are not fully understood at the moment. It is not immediately clear to us how moving the spot position on PR2 would result in the OLG changing like this. 

In any case, we think we want to be able to continue moving the spot by moving PR3 in +yaw because the A2L coupling was getting better as we did (dtt_pr2_spot_a2l.png. So it would be nice to be able to repeat this and move further without losing PRMI. 

The DTT used for the A2L coupling measurement lives in my home directory under Templates/pr2_spot_move_a2l.xml. The 8.125 Hz line was injected using awggui.

TITLE: 08/27 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Corey
SHIFT SUMMARY:

Elenna's current Manual Initial Alignment steps: 
Get ALS Gaurdians for Y arm to ETMS WFS OFFLOADED [13], (except X arm is messed up so only for Y arm currently). ETMX was left in Locking [-23] and ETMX and TMSX were touched up to maximixe the ALS-C_TRX. 
Then once they are locked and stable. unlock them.
COMM Beatnote was 6.5 
DIFF was -9 ish
Then use ALIGN_IFO to start a manual Initial alignment. But we cannot use ASC at all because the diodes need to be "rephased" something about the sidebands are all different now.
This means we take ALign IFO to  AQUIRE_XARM_IR[11]. Once that is done.
We go to Aquire PRX.  Moved PRM to to maximize ASC-AS_A_DC_NSUM.
Then went to Prep_for_mitch[41] > mitch dark locked and moved the beam splitter while watching the AS Air cam for maximum darkness and a ring around a center dot.
SR2 Align[58] was ran and automatically worked. Which uses a QPD and does not need sidebands.
Moving SRM while in SRY_LOCKED[62] to maximize ASC_AS_A_DC_NSUM. 
AS_CENTERING[77] also ran with out intervention.
Then take the power back down to 2 watts.
We are ready to try locking!!!

The Verbal Alrams did a weird thing today. The VAC Alarms sounded off for PT-134  , PT152, and PT-180... 
I called Travis over to come check it out and he said everything looks fine. 
PT-134 is tripped due to someone's phone tripped it a while ago.
PT-152 is correctly telling us the pressure because that sensor is indeed at atmospheric pressure between HAM 5 and 7.
And PT-180 was replaced on tuesday but it's new channel name is PT-180_MOD2 now instead of MOD1.
Which brings up the great point that the Verbal's VAC alarm channels need to be updated.

PEM note: 
A garbage truck slammed a garbage dumpster on the ground around 22:49 UTC today. It was felt in the ground by multiple staff's highly calibrated foot seismometer.

Craning over X arm never happened because they ran out of time. Even if it is mentioned in the Reservation system table below.

LOG: 

Mitch, Camilla, WP#13559

Tyler modified the D2500166 as it was too wide to sit next to the Oplev laser enclosure. Tyler modified: D1300702 and D1300703 so that the box is now ~0.75" offset of the center. Will add more deatils to these modifications in the DCC. 

At the X-arm adapter plate this technically fits but is close to interfering with the  op-lev laser enclosure. The 10-32 bolt next to it will want to be replaced with a button or countersunk bolt.  Photos attached: side view, below view, ruler.

At the Y-arm adapter plate this fits well. Photo attached: side view, below view, ruler.

Comparing the buildup of H1:LSC-POPAIR_B_RF18_I_ERR_DQ between Nov 2025, at GPS time 1447346785, POPAIR RF18 I has a maximum of 168 counts. Today, while locked at PRMI with the buildups maximized, the same channel has a maximum of 62. This means that we are missing more than 70% of the power along this path.

We have previous trends from Ryan S and Ryan C, but they might have trended a normalized channel, which is confusing because the input power and the way we power normalize these channels has changed. Comparing the ERR channels is more straightforward.

POP A LF maximum was about 88 and now it is about 32.

Referencing these alogs: 91622, 91528

Keita has also confirmed that the whitening gains and digital gains of POPAIR RF18 and the modulation depth settings are all as they should be between these two times.

***

I also looked up a MICH dark time since we are getting very confused about what power we actually are or are not missing. Here is a table summary:

MICH DARK: 1432426657, ALIGN IFO STATE 43, May 28 2025

Here is a table summary of the PRMI time:

PRMI locked: 1447346762, ISC_LOCK state 52, Nov 16 2025

Conclusion:

Sheila and I think that the MICH dark numbers actually hang together. This is further bolstered by the fact that we can only make marginal improvements to the alignment onto POP diodes with picoing the HAM3 pico. We think the larger discrepancy in the popair diode in MICH DARK can be accounted for by the fact that the beam is close to the edge of the periscope mirror. We also manage to make the ALS alignment worse with the pico. Therefore, we think the pico alignment is fine.

However, the PRMI numbers clearly indicate a problem, but this points to PRC clipping instead.

The annulus ion pump for BSC9 just railed, about 15 minutes ago.
Nothing to do for now, but we will asses ASAP to see what is wrong with it.

[Jim, Shoshana]

Yesterday when I went to put the cover on the CRS to get it ready to move to the clean area right next to HAM3, I noticed one of the flexures (SN 15) was broken [picture attached]. It's unclear how this flexure broke as it had been locked since last Wednesday (?), and it is strange that only one flexure broke.

We decided that it would be better to install a new pair of flexures and re-suspend next to the chamber rather than in the temporary clean room to reduce the risk of them breaking again. So today we wheeled the table the CRS is on to the space next to HAM3 and I re-suspended the CRS there and roughly balanced it.

Following the procedure outlined in E2600210 and work permit 13356,  we moved the CRS to the table and lined everything up so that the CRS baseplate can be bolted directly to the table in one spot.

We installed the fiber feedthrough, and dealt with all the cabling (fiber and DB25) that required Jim to be physically inside the chamber and we'll install the rest of the cable clamps which we can reach from outside the chamber tomorrow and finish connecting all the cables and dog clamping the CRS down (hopefully)