TITLE: 01/08 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 158Mpc
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
    SEI_ENV state: USEISM
    Wind: 8mph Gusts, 5mph 3min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.51 μm/s
QUICK SUMMARY: Locked for almost 10 hours, just had an event candidate. We are just on the threshold for the seismic environment to be in Calm or Useism, so it has switched back and forth a few times over the night. No other alarms or other notables.

TITLE: 01/08 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 160Mpc
INCOMING OPERATOR: Tony
SHIFT SUMMARY: One lockloss this shift with an automated relock other than opting for an initial alignment once at DRMI. I also adjusted the OPO temp while relocking. H1 has been locked and observing for about 15 minutes.

• 04:09 - Lockloss (alog82172)
  • Opted for initial alignment since DRMI looked poor
  • Adjusted OPO temp while relocking (instructions from alog80461, screenshot attached)
• 05:46 - H1 back to observing

Lockloss @ 04:09 UTC - online lockloss tool is down as of 16:07 PST (currently broken link: 1420344601)

No obvious cause. No real sign of an ETM glitch either.

FAMIS 31067

PMC Refl is back on the rise again after having been steady for about a week. The ISS diffracted power has been slowly dropping also; if it gets worse in the coming days I can bring it back up with a RefSignal adjustment.

No other major events of note.

Since I had some time, I quickly measured the OLTF of ALS PDH at X and Y using LSC EXTRA channels I connected some time ago (alog 80826). I enabled the IN2 and made sure that OUT2 is connected to IN1 (1st attachment). With this setting, H1:LSC-[XY]_EXTRA_AI_2/H1:ALS-[XY]_REFL_ERR_OUT_DQ is 40dB smaller than the OLTF, see the circuit diagram of the CM board (D040180 especially page 5) and an overview (D1002416/005).

It turns out that the PDH OLTF (2nd attachment, note that there's a factor of 100 in the denominator so you have to add 40dB) is about 10dB smaller in ALSY with the nominal setting (red) than ALSX (black dashed) despite that H1:ALS-Y_REFL_LOCK_LOCKEDGAIN (6dB) is 2dB larger than H1:ALS-X_REFL_LOCK_LOCKEDGAIN (4dB). So there's a total of 12dB gain difference somewhere upstream of the common mode board.

That shouldn't be such a big deal once it's locked, but it could be problematic for acquisition as H1:ALS-Y_REFL_LOCK_ACQUIREGAIN was -20dB while  H1:ALS-X_REFL_LOCK_ACQUIREGAIN was and is -6dB. In other words, the electronics gain is 14dB smaller for Y than X and the sensing gain upstream of the common mode board is 12dB smaller for Y. It's 26dB difference in total.

I wanted to adjust the demod phase in Y but was distracted by something else, so I just increased the gain setting for Y: H1:ALS-Y_REFL_LOCK_ACQUIREGAIN is -12 (originally -20),  H1:ALS-Y_REFL_LOCK_LOCKEDGAIN is 10 (was 6).

For LOCKEDGAIN, I tried 14dB and it started dropping lock for unknown reasons, 12dB was OK (brown trace) but I just didn't want to get close to 14dB.

I'm pretty sure ACQ gain could be increased further but -12dB is the gain I tested first and it locked quickly, and I didn't have time.

On Monday I used some templates that Sheila pointed me toward to get some data on HAM ISI coupling to DARM, to see if any of HAMs 2,3 and 6 are close to be a limiting noise anywhere. I did the injections using the templates Sheila gave me, I then used a script from Arnaud based on some of the pem scripts used to estimate couplings. For each table I got excitations in the vertical(Z), beamline (X or Y) and pitch (RY or RX) dofs. This was a first attempt, I think I will probably want to try doing some of this measurement again, but I'll wait to talk to Arnaud a bit about the data.

For each attached image, top subplot shows the quiet ISI dof in black, the injection is red. Bottom plot shows DARM and the estimated couplings for the dof.

None of these are really stand out to me, but maybe my injection could use some tuning.

Templates for each measurement are in /ligo/gitcommon/NoiseBudget/aligoNB/aligoNB/H1/couplings/ISI.

TITLE: 01/08 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
INCOMING OPERATOR: Ryan S
SHIFT SUMMARY: Maintenance day today, with autoamted relocking aside from some testing of SRY locking and ALS during initial alignment. Keita worked on the ALS X&Y and some changes were made to ALSY that seemed to help relocking. We've been locked for 2.5 hours
LOG:

• 1647 Lock loss, LVEA activities for maintenance
• 2027 Initial alignment started
• 2154 Observing

I've updated the PEM_MAG_INJ and SUS_CHARGE Guardian nodes to not run their associated injections and drop H1 from observing if there is an active stand down alert from SNEWS, Fermi, Swift, or KamLAND (for supernova, GRB, and neutrino alerts). As a reminder, these normally start at 7:20am local time on Tuesdays if H1 is locked.

TITLE: 01/08 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 158Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: USEISM
    Wind: 3mph Gusts, 2mph 3min avg
    Primary useism: 0.05 μm/s
    Secondary useism: 0.46 μm/s
QUICK SUMMARY: H1 has been locked and observing for over 2 hours.

• Wind is low, microseism hanging out around 95th percentile
• LAB2 DM still has readback error
• All other systems nominal

FAMIS27806

No water was added to either chiller as both were near the max. All filters looked okay for now and there was no water in the leak detection Dixie cup.

T2200289 was updated with these values.

In 81863 we looked a the RIN of the CO2 lasers on vs off. Today we repeated with PWM (from Synrad UC-2000), the noise level is considerably higher when PWM is on. Note that this isn't really the RIN as we're not dividing by the DC power.

Data saved to camilla.compton/Documents/tcs/templates/dtt/20250107_CO2_RIN.xml and 20250107_CO2Y_RIN.xml

• Refs 0-3: Laser on CW
• Refs 4-7: Laser off.
• Refs 8-11: 50% PWM (CO2X laser locked, CO2Y unlocked)
• Refs 12-15: 25% PWM (CO2X laser unlocked)
• Refs 16-19: 95% PWM (CO2X laser relocking)
• Refs 20-23: Laser on CW

The CO2Y plots also show the dark noise as there is no photo detector plugged into CO2Y_ISS_IN.

• CO2Y plots: AC only, DC only, all.
• CO2X plots: AC only, DC only
  • It's strange that there more CO2X DC noise with the laser off and that the 25%, 50%, 95% PWM's are the opposite way around for the AC and DC outputs.

For some of the CO2X data, the CO2 guardian was relocking (sweeping PZT), noted above.

FAMIS 28387, last run in alog81957 (Dec 17th)

ETMY looks to have had the greatest changes since last measurement, other test masses look close to nominal.

WP12271

We investigated the SHV cable connectivity between the Ion Pump Controller at EY and the Ion Pump at Y2-8 checking for faults.  We did not detect any obvious faults, we did detect the prior splice which was installed back in 2016.  We used the Fieldfox in TDR mode with a 1.2 meter launch cable in low pass mode. I have attached scans of these findings:

First photo is a shot from the Controller, there is a large impedance change at 19 meters from the connection point, this is the same location of the splice made in 2016, the repair looks like we would expect a splice to look.
https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=28847

Second photo is a shot from the Ion Pump back to the end station.  There is a very small bump at 20 meters from the ion pump that is real, but is very very tiny, could be a kinked cable, but not enough to cause issues.

Otherwise, the cable looks fine.  Future testing is warranted.

M. Pirello, G. Moreno, J. Vanosky

FAMIS 22015

pH of PSL chiller water was measured to be just above 10.0 according to the color of the test strip.

Sheila, Jennie, Camilla. Last done in 76040. Want to get a homodyne measurement in our new OPO crystal spot location 82134, would plan to then repeat this a few months later to see any difference.

Aligned the homodyne but ran out of time before taking any data. May try to repeat on Thursday during commissioning.

Sheila offloaded the IFO ASC and edited the guardian code for clearing the ASC so that it now includes clearing the integrators that we moved into the ZMs.

Turned up SEED injected power from 0.7mW to 72mW to match the power from the LO (0.544mW on HDA and B). We later turned the LO power down with the pico HWP to match the SEED power.

Jennie adjusted the LO beam with SEED beam blocked to improve the subtraction: Checked we were centered on PDA/B using the steering mirrors downstream of the HD BS and then measured the HD DIFF spectrum. Adjusted BS, re centered on HD PDs and re-checked if DIFF spectrum shot noise had improved.

Sheila and Jennie aligned the SEED beam onto the LO beam. We expected to be able to see fringing on HD A/B at this point but couldn't, tried adjusting the alignment with ZM4, didn't help. It turned out tat the fringing was there, clear when using an oscilloscope just unclear on ndscope. Sheila further tuned the SEED alignment to minimize fringing. We measured peaks at 1.85V, bottom of fringes at 29mV with 2mV dark noise, giving visibility of 97.1%.

Then went back to the control room and measured NLG like normal (OPO to LOCKED SEED NLG), NLG = 10.3. Sheila turned down the SEED beam back to 0.7mW. 

Then could start to take HD SQZ measurements, Using SQZ_MANAGER to SQZ READY HD (takes LO to LOCKED HD) and OPO to LOCKED_CLF_DUAL. We needed to increase SHG power from 10mW to ~16mW to allow 80uW on OPO Trans.

Plot attached: Dark noise was the same as original plot, LO shot noise (ref10), With NLG 10.3,  ASQZ was 13.8dB (ref2), this seems similar to last measurements.

We planned to take ASQZ/SQZ data at different NLG's, however I was having some issues with the OPO GRD unlocking and ran out of time. May continue on Thursday during commissioning time.

Sheila, Camilla

Following up on 82039, where Vicky remotely helped Oli to recover the squeezer alignment.

We have a state called RESET_SQZ_ASC (FDS or FIS), which can be used after something goes wrong with the ASC and someone wants to get rid of what the ASC has done.  This state hadn't been edited since we moved the ASC integrators to the suspension lock filters, so when Vicky and Oli tried it the ASC wasn't really reset making it more difficult to recover from that situation. 

Today we added the LOCK filters to this state, and loaded and ran it.  This should make things a little bit less confusing to debug next time.

Recently we've been having some issues with SRY locking in initial alignment where even though flashes at AS_A are good, it wouldn't catch the resonant cavity. My thought was that the suspensions are moving too much to catch, and then it would run through the DOWN state after failing to hold it, moving the suspensions again. During initial alignment today this happened to me, so I waited in down for a bit and then tried to lock. It locked straight away, possibly confirming my suspicions. From this, I bumped up a timer in Prep_For_SRY in the ALIGN_IFO node to allow SRM to settle a bit more before trying to acquire. Hopefully this will help with the SRY locking issues we've been having, but I'll keep an eye on it.

Code changes have been loaded and committed.

All maintenance activities have completed for the day except for squeezer work which will continue while I finish initial alignment.