TITLE: 10/29 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: Currently trying to relock and at PRMI after a productive maintenance day and finishing up of PSL work.
LOG:

22:48 Started manual initial alignment
22:59 Manual initial alignment done, relocking                                                                                                                                                                                                                                                                                                                                                                                                             

TITLE: 10/29 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 14mph Gusts, 9mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.23 μm/s
QUICK SUMMARY:

IFO is LOCKING at PRMI

PSL Maintenance was ongoing throughout the day with PSL work finished (for now).

We've gone through a manual initial alignment and are now locking, which is apparently optimistic.

Daniel noted that the new NPRO is almost certainly at a different frequency than the previous one.  Also, since the PSL has been the most 'fussy' lately, we don't want to change it away from it's manufacturer-recommended settings (if we can help it), and instead want to change the other 3 lasers to match the new PSL frequency.

In the attachment, the top row is SQZ laser, the middle row is ALSX, and the bottom row is ALSY.  The leftmost column is the beatnote frequency between the given laser and the PSL, the middle column is the CrystalFrequency offset that we can provide, and the right column is the amplitude of the RF beatnote.

To figure out "where to go", Daniel put in a set of steps (eg, using ezcastep) to the CrystalFrequency channels. You can see that he started with the SQZ laser, but wasn't finding it by using a positive frequency offset.  He then found (using ALSY) that putting in a negative frequency offset of a little over 4 GHz (the CrystalFrequency numerical value is in units of MHz) brought the RFMON up, and the PLL loop was able to engage and bring the beat frequency to the right spot.  Once the RF mon started increasing, he Ctrl-C'd to stop the stepping of values.  Knowing that all 3 of these aux lasers at one point were matched to the PSL, he then set the SQZ laser and the ALSX laser to search around that -4 GHz value.  In order to have the PLL loops engage and not complain, Daniel set the H1:ALS-X_FIBR_LOCK_TEMPERATURECONTROLS_HIGH and _LOW settings for all 3 lasers to be a wide acceptable window (eg, +/- 6000 MHz, rather than a normal +/- 600 MHz).

Once all 3 lasers had their PLLs locked, Daniel and Vicky went out to each laser to adjust the nominal temp such that the CrystalFreq offset can be closer to zero.  My understanding of the procedure is that they will (with the PLL locked using the big offset) take a look at the current temp of the laser, according to the little LCD display on the front panel of the laser controller.  They will unlock the PLL and set the CrystalFrequency offset to 0, and then adjust the analog knob on the laser controller such that the temperature is back at the temp it was with the PLL locked with big offset.  They'll then allow the PLL to relock, hopefully not needing a very big CrystalFrequency offset.  While at each laser, they will also check that the laser is not in a mode hopping region with this new temperature.

After this is done, and once the PSL tune-ups are done for the day, we'll be able to start locking!

Our frequency noise and contrast defect (measured at the OMC) are lower than they ever have been in O4 (contrast defect, frequency noise). As a part of trying to track down what may have caused this reduction, I tracked the coherence of DARM with the LSC REFL A RIN, using that as a witness to frequency noise, as it was used in OAF for online frequency noise cleaning in O4a (source: 72276 and poking around the OAF screens).

I tried to pick times that were a few hours into the lock to avoid thermalization confusion. I also used only observing data.

There are a couple ideas about what could have caused this improvement. A short list:

• ring heater/power changes: we have stepped up and down the ring heaters by 0.1 W to avoid PIs, and briefly stepped up the input power by 1 W for the same reason
• AS WFS yaw offset: this was turned on due to an investigation in the O4 break, and then turned off after the OFI vent recovery
• OFI change: this doesn't help match the arms, but changes the mode matching to the OMC which could effect the contrast defect

These are the times I used. All of these times were at the same 60 W input power from the PSL:

Dec 10 2023: O4a time, no WFS offset in use, EY ring heater set to 1 W (1386244818)

Apr 11 2024: O4b time, before the OFI problems, WFS offset in use, EY ring heater set to 1 W (1396950886)

Jul 10 2024: O4b time, just before OFI repair vent, WFS offset in use, EY ring heater set to 1 W (1404656647)

Sept 14 2024: O4b, after OFI repair, WFS offset in use, EY ring heater set to 1 W (1410432000)

Sept 20 2024: O4b, after OFI repair, WFS offset set OFF, EY ring heater set to 1 W (1410855190)

Oct 22 2024: O4b, after OFI repair, WFS offset set OFF, EY ring heater set to 1.1 W (1413635762)

Here are some notes for the comparison of these times:

• the frequency noise coherence dropped significantly from O4a to O4b (red trace to blue trace)
• the frequency noise coherence increased again after the problems with the OFI (blue trace to green trace)
• the frequency noise coherence improved again after the OFI vent recovery (green trace to brown trace)
• the frequency noise coherence improved further after we turned off the WFS offset (brown trace to pink trace)
• the frequency noise coherence stayed the same when we changed the EY ring heater to 1.1 W (pink trace to light blue trace)

All of these O4 times show less coherence than the O4a time. Based on this data, it seems like the WFS offset did have an impact on the frequency noise. It also seems like the various vents with output port changes could affect the frequency noise, but the overall beam alignment in the arms could have changed during the vent. For example, we did adjust the camera offsets/ADS gains during the vent commissioning times. The change in frequency noise during the OFI problems (between April and July) could have a similar source, since we had to change a lot of alignment during that time. I'm not sure if any arm alignment was significantly changed though. Finally, it seems like this small ring heater change had no effect on the frequency noise.

I have updated the plotallhlts_tfs_M1.m matlab script to allow the user to plot any potential cross-coupling. There is a newly-added boolean near the top called plotOffDiagonalTFs that can be set depending on whether you want to see the off-diagonal plots or not, and there is also a coupling matrix that can be changed depending on what coupling you want to see. The plots get appended to the end of the regular transfer function pdf file, allhltss_*_ALL_TFs.pdf. Attached is an example of how the cross-coupling plots are laid out. The script has been committed to svn as part of revision 12063.
 

I preemptively swept the LVEA since it seems like the PSL work will complete soon. The only things of note are I ended up unplugging 5 unused extension chords.

The last remaining items are: PSL in Science mode, wifi off, LVEA lights off, PSL phone unplugged in 163.

Looking at the CO2 ISS PD trends (qty 2 on each table labeled IN and OUT of loop), as the CIT CHETA setup that uses this PD is still getting confusing results (e.g. CIT#481). Each PD as an AC and DC mon output, from the DB9 of the PD preamp board D1201111.

Inially the DC signals look as expected, dropping to zero when laser is off (CO2X plot / CO2Y plot). CO2X stays within 1% when the laser is stable (CO2X plot). Though the CO2Y plots looks worse, only staying within 5% when the laser is stable (CO2Y plot).

If you pay attention to the ~hour  region once the laser is first turned on in both lasers (worse in CO2Y, see plot) the ISS PDs show power signal varying much more than the CO2 power head PD does. I don't understand why that would be, but this could explain the issues we've seen at CIT where the laser is always ina less stable state as is fan cooled rather than water cooled.

CO2Y_IN shipped to CIT in 80883.

Tue Oct 29 10:08:04 2024 INFO: Fill completed in 8min 0secs

Gerardo confirmed a good fill curbside.

Eric is running the fire pumps this morning for maintenance. This is a good opportunity to test CDS reporting and alarms. Attached MEDM shows CDS Overview with a red fire pumps button, it opens the FMCS overview (also shown). I let the first three cell phone alarm texts to proceed and then bypassed this alarm for the remainder of this morning.

Bypass will expire:
Tue Oct 29 08:41:08 PM PDT 2024
For channel(s):
    H0:FMC-CS_FIRE_PUMP_1
    H0:FMC-CS_FIRE_PUMP_2
 

FAMIS Link:  26015

Only CPS channels which look higher at high frequencies (see attached) would be the following (which have been like this on the order of weeks):

1. ITMx St1 V1
2. ITMy St1 V2
3. ETMy St1 H2

In 80171, we noted that the incorrect coil driver strength had been in use for getting the calibration in plotTMTS_dtttfs.m. We corrected this value and last week I was able to take transfer function measurements of the TMTs, which we wanted to take just so we could verify that the updated calibration was more accurate to the models, and also just because it had been four and two years since taking measurements for TMSX and TMSY, respectively.

I've attached the pdfs for their individual analyses (TMSX, TMSY), as well as comparisons between the most recent and previous measurements (TMSX, TMSY). The corrected coil driver strengths do shift the measurement traces up closer to the model traces.

TITLE: 10/29 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 6mph Gusts, 4mph 3min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.25 μm/s
QUICK SUMMARY:

Maintenance day today

Workstations were updated and rebooted.  This was an OS packages update.  No conda packages were updated.

STATE of H1: Corrective Maintenance
SHIFT SUMMARY: PSL team made major progress and was able to get the second amplifier to output 140W! They will continue work tomorrow to wrap it up.
LOG:                                                                                                                                                                                                                                                                                       

Continuing on from Jenne's observation that there are still glitches in the new NPRO, I've tried to make a plot we can use to compare the glitch rate in the new and old NPROs, using the NPRO_PWR channel instead of the FSS channel which isn't available for the new NPRO. 

I've used a 3 hour stretch of observing time for the old NPRO, and a three hour stretch before the time when Jenne made a plot in 80837.  The ISS is not on for the new NPRO time, which is probably why the intensity is flcutuating and making it harder to see the small steps in power that are the glitches we are looking for.  In the second panel, I've plotted the data high passed with a 0.05 Hz butterworth, this helps to show the glitches, although not perfectly (in either case).  Based on this, the glitches look to be happening at a roughly similar rate, although somewhat less with the new NPRO.

This script in in sheila.dwyer/DutyCycle)4/dutycycleplots/PSL_glitches.py

Vicky, Sheila

Summary:  Today we learned that frequency independent anti-squeezing is a very good way to determine which sign the homodyne angle is. 

Background: I've been working on using code from Vicky's repo and the noise budget repo to do some checks of a quantum noise model, this is in a new repo here. 

Details about how this model is made:

The first attached plot illustrates how these models and plots are made.  It starts with a no squeezing time, and an esitmate of non quantum noises from the noise budget, (dark gray, this one is from Elenna's recent run of the noise budget: 80603  ) and an estimate of the arm circulating power along with other parameters set in a quantum parameters file in the same format that is used by the noise budget.  It fits the readout losses by adding a gwinc model of quantum noise with the noise budget estimate of other noises, and adjusting the readout losses of the gwinc model, this is done from 1.5-1.8kHz in this case.

Based on this readoutlosses we get a model of quantum noise without squeezing, and subtract that from the no squeezing trace to get an estimate of the non-quantum noise.  This is enough different from the noise budget one that I've used that as the estimate of the non-quantum noise for the rest of the traces. 

By subtracting this subtraction estimate of the non-quantum noise, it estimates squeezing in dB, and finds a median level of dB from 1.5-1.8kHz for anti-squeezing and squeezing. This should be the same with and without the filter cavity, but in this data set there is slightly more anti-squeezing in the time without the filter cavity, so I've used FIS and FIAS to estimate the nonlinear gain and total efficiency for squeezing.  The nonlinear gain is translated into generated squeezing for gwinc, and the injection losses for squeezing are set so that the injection efficiency* readout efficiency = total squeezing efficieny. 

With this information we can generate models for anti-squeezing and squeezing traces, but fitting the squeezing angle to minimize or maximize quantum noise.  Then for the mid angle traces, the squeezing angle is fit to minimize the residual between the data and the quadrature sum of the subtraction estimate of non quantum noise and the model. We can then look at these plots and try manually changing parameter in the quantum parameter file.

Homodyne angle:

We've been stumped for a while about the excess noise we see with low frequency anti-squeezing, in 79775  I went through old alogs and see that we've had this mismatch of model with our data for a long time.  Today we tried flipping the sign of the homodyne angle and see that low frequency anti-squeezing is much closer to fit both with and without the filter cavity. Compare the 2nd and 3rd attachments to see this.

We still have more work to do on this model, including adding in the additional traces near squeezing and near anti-squeezing that Camilla took, and checking if it can give us any information about arm power (it doesn't seem very useful for that), or the mode mismatches.