TITLE: 07/03 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: Ryan C
SHIFT SUMMARY:

Today was Thursday Commissioning from 8am-1230pm, and had a locked H1 for 1hr45min of the commissioning time and had a few commissioning tasks squeezed in this time.  

H1 continues to be plagued by ringing up PI Modes that cause locklosses.  So, today different settings continued to be tried (latest & current ETMy Ring Heater setting is 1.5 W for the upper and lower).  But for some of these changes, we have had to try different violin mode settings (for ETMy Mode 20)---see this alog85527.

Also, the input pointing which was lost due to the HAM2 SEI Power supply swap on Maintenance Day, was reverted back by Elenna (alog85533).

Did not get to run the calibration suite today, so hope to do this after H1 gets to 3hrs during RyanC's shift tonight.
LOG:

• H1 was locking at beginning of shift (powering to 25W)
• 1458 OBSERVING (w/ Max Power reached at 1447)
• 1511 COMMISSIONING Begins
  • 1511 Robert's tasks:  (1) Compensation plate scans (finding a new place now that the annulus pumps are off), and (2) More evaluation measurements for Before/After the recent O4-Break.
  • 1557 ETMy Ring Heater lowered to 0.9
    • ~1725 ETMy Ring Heater lowered to 0.6
  • 1619 ETMy Violin Mode gain changed from -1 to 1 (it was seen ringing up)
  • 1635 Calibration (broadband) started, but I accidentally CTRL-C-ed out of the terminal I was running it on (I had tried to "copy" text.).  The CTRL C did not stop the EY PCal excitation.  I needed to get help from Jonathan/Eric to finally get rid of the excitation.
  • 1645 Lockloss (PI 28/29 were ringing up and also trying to get out of the calibration at the time of lockloss).
  • 1728 Initial Alignment started, but stopped after INPUT ALIGN to have
    • Then continue with the Alignment again starting at INPUT ALIGN
• 1717 ISS pd work in optics lab (rahul, jennie)
  • 1740 out for calculations & back before lunch maybe
  • 2142-2230 Heading back in the lab.
• 1806-1836 Beckhoff Machine power cycle in Mechanical Room (patrick)
• 18231905 Running Cables for injections (robert)
• 1852-1908 Matt & parents took peek in LVEA
• 1857 NLN
  • 1952 PI28/29 Lockloss
  • ETMy Ring Heater increased to 1.5 (from 0.6).
• 1910 Running new Broadband Calibration (attempt #2---and I won't try to "COPY" anything!)
  • 1947Running for 3rd time....
• 1952 LOCKLOSS due to PI 28/29
• 2025 Initial Alignment run since DRMI & PRMI didn't catch, and it was close to 30min since the lockloss.
• 2120 NDS0 crashed----Erik restarted and we restarted FOM ndscopes.
• 2135 Back to OBSERVING.  To get here, had to:
  1. Accept the SDF Diffs for the newest ETMy Ring Heater laser power (it is now at 1.5 for upper and lower)
  2. And for the Squeezer, the SQZ_ANG_ADJUST had to be taken to DOWN to get the SQZ MANAGER to its nominal state.
• ETMy MOD20 started to ring up again and this is with the new ETMy Ring Heater laser power of +1.5
  • +30, -1.0---ring up
  • +30, +1.0---ring up
  • +60, +1.0---Damped it down & worked.
• 2259 -2301Dropped from Observing for SQZ changes (Sheila).

I started adding a state to the OPO guardian this morning while we were unlocked that scans the OPO temperature while the CLF is locked, and sets it to the temperature that maximizes CLF 6 Mz power in reflection off the OPO. 

The code is based on the SCAN_SQZ_ANG guardian state and it produces plots here: https://lhocds.ligo-wa.caltech.edu/exports/SQZ/GRD/OPOTEMP_SCAN/OPOTEMP_SCAN_250703142801.png

Screenshot shows that exmpale was a 1 minute scan with a 0.02 degree C range, this was a bit too fast for the TEC servo to keep up with so I've slowed it down to a 2 minute scan for the next time we try this out. 

Operators can use it to adjust the opo temp, by opening the SQZ_OPO_LR guardian and requesting SCAN_OPOTEMP.  I haven't tried this while squeezing was injected into the IFO, but it should work fine to do it then (not while in observing).   For future work we could add management that runs this each time the IFO relocks, but I haven't done that now.

Also note: This morning I set the sqz params to stop using SQZ ASC and start using the ADF servo for the squeezing angle.  These two can't run at the same time and I think that controlling the squeezing angle would be more beneficial right now.  However with various things we didn't get to test this and now we are observing with both ASC and the ADF servo off.  We momentarily dropped out of observing to engage the servo.  I also added to the SQZ_ANG_ADJUST guardian an if statement that updates the nominal state looking at sqzparams to check if the servo is supposed to be on or off in the guardian.   This will be compatible with the script that allows observing without squeezing for this weekend, but that script hard codes what the nominal state is, so in the long run we need to do something else.

TITLE: 07/03 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 146 Mpc
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 14mph Gusts, 8mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.06 μm/s
QUICK SUMMARY:

• We've been locked for 1.5 hours, we just finished running a SQZ_ANG scan
  • 23:01 UTC Observing
• Locks have been short the past day due to a ETMY PI from the ring heater
• Once we are thermalized I will be dropping from Observing to run a calibration measurement

Jennie Wright, Rahul

Earlier, we have measured the QPD readout per mm to be around 44.1V (in X direction). This afternoon we dithered the input beam (spot size, radius = 200 microns, see LHO alog 85458) in horizontal and vertical direction at 100Hz using the signal generator (amplitude 2V peak to peak and offset 2.5V). This we did after centering the beam on the QPD (output was around 10,500 counts approx.). The output voltage applied on the dither was around 80V. Given below are the results,

Horizontal dithering:-

On the QPD the dither amplitude X (peak to peak) was estimated to be 2.2V, Mean 6.5V

Beam motion estimate X= 50microns

Dither amplitude Y (peak to peak) was estimated to be 1.2V, Mean -355mV

Vertical dithering:-

On the QPD the dither amplitude X (peak to peak) was estimated to be 1.0V, Mean 4.45V

Beam motion estimate X= 20microns

Dither amplitude Y (peak to peak) was estimated to be 1.62V, Mean -7.96V.

During some ndscope testing Erik ran into a file descriptor limit on h1daqnds1 that required us to restart daqd.  The daqd stopped accepting requestions, giving a log message that the accept call had failed.  We bumped the file descriptor limit up and that solved the issue.  We have made runtime changes (no restart required) on h1daqnds[01].  We have put the new limits into the daqd puppet, but have not applied them yet.  We will reconcile the systems with puppet next week, after the long weekend.

with help online from Joe B

I revised this title to "attempted" because this push has failed and we reverted to the calibration from 20250610T224009Z.

Today I pushed a new calibration from calibration report 20250628T190643Z. We changed the SRCL offset on 6/26 which had a small effect on the sensing function, enough that Joe and I (with input from Sheila) decided to push a new calibration. With the change in the sensing function, I tagged a previous report on 6/26 with epoch-sensing and epoch-hfrl. When I regenerated the report, I set is_pro_spring to empty, since the previous iteration of the report showed that there was very little spring in the DARM sensing measurement, at least to 10 Hz. I confirmed with Joe that the resulting corner plots for the sensing that show very poor fits for F_spring and Q are ok- this is because the pipeline is unable to fit any appreciable spring in the sensing function.

I checked the GDS filter results by eye, and confirmed they all looked flat. I then went ahead to push this new calibration, following steps we took last time, specifically:

pydarm commit 20250628T190643Z --valid

pydarm export --push 20250628T190643Z

pydarm upload 20250628T190643Z

pydarm gds restart

Then, we waited ten minutes to begin the calibration measurement. This is where I made an error- I checked that the GDS calib strain channels all looked sensible, and I saw some lines updating on grafana, so I assumed we were good to go. Corey began a calibration suite, which starts with a broadband measurement. However, the broadband results were not very good. We lost lock right at the end of the measurement. This was my mistake- I never checked if kappaC and kappaTST had settled, which it looks like they hadn't. So, I think we need to relock and check the calibration again. If it still looks poor, we can revert to the previous calibration. This must be done before we go back to observing.

Follow up edit below here:

We relocked after the push above and remeasured and saw the calibration was even worse than before (orange trace). We think this may be a fit error to the L2 actuation function, but we're not sure. Joe helped me revert the calibration to the previous version, from 20250610T224009Z. Corey and I ran an early broadband and saw the error was better, red trace. Still not the best, but we were not thermalized yet. Hopefully we can try a new push next week with a better cal.

Sheila, Matt, Corey, Elenna

I reverted the IM2 and IM3 osem positions in order to bring the beam on IM4 trans QPD back to its position before the mystery shift reported in alog 85486. I started by moving IM2 pitch, and noticed that bringing it back towards its previous position did help return the beam on IM4 trans to its previous spot. It was also very largely cross coupled with yaw, and shifted the yaw position slightly as well. I then moved IM3 pitch and further brought the pitch offset on IM4 trans back. I tried adjusting IM2 and 3 yaw slightly, but the adjustments to bring the yaw osems back did not correspond with returning the yaw IM4 trans position to the previous one. Overall, the shif tin yaw position is very small, so I chose to not make any more moves in yaw.

Corey reran input alignment, and I moved PR2 and IM4 by hand significantly in pitch (tens of microradians for both) to get the lock to catch.

While we locked, I reset the POP A offsets to well align PRM to the full lock alignment. This is SDFed in safe, but will be an observe diff too.

The attached ndscope shows the movement that I made. The y markers on the osem plots indicate where the suspensions were before the mystery shift. Note: IM1 also shows movement, but I chose not to adjust it.

Kevin, Matt, Sheila, Elenna, Corey

After yesterday's ETMY RH change to avoid the 10kHz PI 85514, we lost lock 3 times overnight due to 80kHz PIs.

Apartently the RH change also changed a violin mode damping phase for ETMY 1 kHz mode (mode 20 1000.307 Hz), 85526, which did not cause the earlier locklosses but is growing to the point where it is dominating the DCPD RMS in this lock, but responded well the Elenna's sign flip.

Kevin took a look at the 10kHz higher order modes, second attachment.  The top panel shows how the higher order modes have been thermalizing before the ring heater change, the bottom panel shows three locks since the ring heater change which is a few minutes before 2 hours into the lock, so these can be compared to the green trace in the top panel. THe x arm higher order modes are sitting around 10.6kHz at this point in the self heating thermalization, the yarm modes were below the scale on this plot before the change and are now moving up to around 10480Hz.   If they gain another 20Hz as the self heating kept thermalizing similar to the x arm, this would have put them around 10500 Hz which doesn't have a lot of accoustic modes visible here. 

We don't want to revert the ring heater change from last night as that setting had the y arm sitting right below the forest of accoustic modes.  Matt estimates that we could move the y arm below this forest of accostic modes by going to 1.5 or 1.6W per segment, but that would mean that our two arm modes are more different from each other.  First we tried lowering the power a little more, to 0.9W per segment to see if that helps the 80 Hz modes.  Then Matt estiamted that we could put the Y arm 2nd order mode in a similar location to the x arm by using 0.6W per segment, so we've now set them to that.

Matt took a reference here before the PI rang up, it looks like the PI is 80297 Hz, I got a reference that includes the peak and the lockloss transient, which shows the frequency as 80298 Hz. The signal used for the PI damping is DCPDs downconverted at 80kHz, with a bandpass that goes from 294 to 298.5 Hz, so our peak is within the bandpass. The PLL set frequency is 299Hz, we lowered this 297.5Hz. It was being sent to ETMX for damping, which did appear to work once but not as the mode grew.  We think this is a y arm PI, since we have been changing the Y arm ring heaters, so I've changed the output matrix to send this to ETMY.

Thu Jul 03 10:11:40 2025 INFO: Fill completed in 11min 36secs

Sheila, Matt, Elenna

In the midst of trying to diagnose various PI issues, we noticed DCPD sum was slowly increasing, but not from PIs. We eventually figured out it was ETMY violin mode 20. The gain was set to -1. I flipped it to +1 and then mode started being damped down.

Thought I had posted this before, but couldn't find it, so here it is.  Attached plots compare L2L measurements of the HAM1 GS13s on May 21 during corner pumpdown before adding the periscope viton and June 6 the afternoon after we added viton. The Q and frequency of the 71.8hz mode is somewhat reduced, but the neighboring 69.9hz mode is sharper now, so I'm not sure we gained much. The June 6 measurement was collected in air, so I would still like to collect a set of in-vac measurements. This could probably be done on a Tuesday if there isn't too much activity around HAM1.

TITLE: 07/03 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 5mph Gusts, 2mph 3min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.07 μm/s
QUICK SUMMARY:

H1 had (3)  ~2-hr locks overnight (looks like no wake-up calls for Oli!).  H1 is currently locking (just powered up to 25W).  Winds stepped down at about 130amPDT (837utc).

Today is Thurs Commissioning from 8am-12pmPDT (15-19utc).  H1 won't be thermalized until about 1030-11amPDT, so no calibration...hopefully H1 short locks won't be an issue for calibration where we need H1 thermalized 3hrs.  Robert and Sheila will probably start their work

Jennie W, Rahul

Yesterday we made some measurements to calibrate the spot size on the QPD as we scan the beam position across it.

We used a connector Fil made us to plug in the OT301 QPD amplifier into a DC power supply after checking it contained voltage regulators that could cope with a voltage between 12 and 19 V ( as the unit says it expects DC supply but the previous one we were using was AC with a 100mA current rating and was getting too hot so we assume that was the incorrect one). We hooked it up at 16V (this draws about 150mA of current). The QPD readout looks normal and does not have any of the strange sawtooth we saw with the original power cable.

We moved the M2MS beam measurement system out of the way of the translation stage.

To calibrate the QPD we need to change the lateral position of the M1 mirror and lens to change the yaw positioning on the QPD and measure the X and Y voltages from the QPD.

We need to check we are centred first. The QPD bullseye readout shows the beam is off a tiny bit in yaw but this was as good as we could get at centering the beam when we moved the QPD. All 8 PDs are reading about 4.6 V so this means the beam is well centred in the array plane.

We measure 11000 counts on the bullseye qpd readout at this M1 position.

I plotted the data from lowest reading on the translation stage to highest and fitted the linear region using Calibrate_QPD.m which is attached.

Data is shown in attached pdf.

The slop of the linear region in V/inch is 112 V/inch. Which means to if the beam moved 8.93 e-3 inches on the QPD in yaw, the yaw readout would change by 1 Volt.

Jim, TJ, Robert

We damped the periscope on ISCT1 by removing the dog clamps one by one and inserting a strip of 1/16" viton between the dog clamp and the base of the periscope before retightening, making sure that the strips crossed the corner of the base. This is not the most effective way of damping the periscope but it was the fastest, safest and most simple damping we could do. Jim measured the Q to be around 1000, so we didn't have to do much to get an improvement. In Jim's first transfer functions after the damping, the peak looked a little wider.

FranciscoL, RickS

On April 4, 2024 we used DTT to measure the amplitudes of the Pcal lines used in the Pcal X/Y calibration comparison in both the Pcal end station Rx sensor outputs and the DARM_ERR signal.  The attached plots shows the peaks in the spectra measured with 0.001 Hz requested BW, 50% overlap, 10 averages during a long lock stretch.  The second image is a page from Francisco's lab book.

The SNRs for the lines from the Pcal Rx sensors is about 5e-5 and

the SNRs of the lines in the DARM_ERR signal are about 1350.