I noticed on the ops overview last night that there was an orange "Stand down alerts query failure" light. Looking at the journald log located on the ext-alerts vm, looks like it crashed on Jan 11, so our automated stand downs haven't been working since then, but the incoming events were unaffected. The error was that it wasn't able to connect to the superk site after so many retries. I've restarted this for now with the hope that it was just some maintenance or similar on thier end, but if it crashes again I'll find a more robust solution.

Tue Jan 14 10:03:25 2025 INFO: Fill completed in 3min 22secs

TCmins [-65C, -63C] OAT (0C, 32F)

Sheila, Mayank

We wanted to double check the calibration of IM4 trans into power on PRM, similar to 63812 and 62213

• 10 Watts, single bounce ITMY 16:24 UTC
• OMC locked 16:35 UTC.  Sensor correction was off so this alignment is wobbling more than it otherwise would. 
• sensor correction on 16:40 UTC - 16:45 UTC.  1420908058 for 300 seconds
• IM4 trans and AS_C whitening gains were 18dB at the time of this measurement. 
• Medians:
  • H1:IMC-IM4_TRANS_NSUM_OUT16 9.855005
  • H1:IMC-PWR_IN_OUT16 9.997126
  • H1:ASC-AS_C_SUM_OUT16 0.007815647
  • H1:OMC-DCPD_SUM_OUT16 15.558
• Using Craig's code here to get all the optic transmissions (he cites where the numbers came from at the top of the file), we expect 0.244% of the power incident on PRM to reach HAM6 in single bounce. 
• If we continue to trust the calibration of AS_C, and the known transmissions that Craig collected, we would apply a correction of 0.9566 to IM4 trans.

All h1omc0 models (h1iopomc0, h1omc, h1omcpi) were restarted with version 5.3.1 of the RCG.  This version changes the ramp function when turning on and off ramp-switched filters from a linear ramp to the so-called quadratic ramp. 

A linear ramp has the formula r = q  where q = (t - t0)/(t1 - t0), the new ramp has the formula r = -q⁴ + 2q², which has the nice property that dr/dq = 0 when q = 0 or q = 1.

This change is an attempt to address the problem described here: 81638

J. Kissel, T. Sanchez, L. Dartez

As we began to use the new OMC DCPD test infrastructure (LHO:78956, LHO:78975) to pick up where we left off in characterizing the new-to-O4, segregated OMC DCPD, 524 kHz low-noise ADC system (LHO:78516, LHO:78559), we found in necessary and fruitful to
 
- shift some of the installed filters around in the A2 and B2 banks (the one's the replicate the reverse-calibration filters that turn the raw ADC counts in mA on the DCPDs; the copies of the A0 and B0 "NewV2A" and "NewAW" -- moved from FM1 and FM2 to FM2 and FM3 like they are in the A1 and B1 banks.)

- add the 1 Hz 5th order elliptic high-pass as an option to the A2 and B2 filters in FM1 (like the A1 and B1 banks) and 

- split out "divide-by-four" gain of 1/4 that turns the sum of the four channels into an average from the "cts2V" ADC calibrating gain of 40 / 2^18 [V/ct] = 0.00015258789 [V/ct] ~ 0.0001526. The ADC gain in th previous cts2V bank was actually implemented as a typo of the 16 bit ADC calibration divided by 4. The ADC gain should be 40 / 2^16 [V/ct] = 0.00061035156 [V/ct], but was installed as 0.0006105 "[V/ct]." And then the multiplication of the gain of 1/2^2 = 1/4 = gain(0.25) to convert from 16-bit to 18-bit calibration was immediately adjacent to the gain(0.25) for turning the sum into an average. Not so clear.

So, what was 
    cts2V = gain(0.0006105)*gain(0.25)*gain(0.25)
in FM4, is now two separate filter banks
    18b_cts2V = gain(0.0001526)
    sum2avg = gain(0.25)
in FM4 and FM5.

The new filter banks and arrangement have been committed to the SVN under 
    /opt/rtcds/userapps/release/cds/h1/filterfiles/
        H1IOPOMC0.txt       rev 30385

Also -- it appears as though the B1 and B2 filter banks didn't have their filters properly *un*monitored when I touched the SDF system last week (LHO:82155). The configuration changes (made during Monday commissioning time) thus had prevented returning to observing. I've rectified that as well, so now, *really* these A1, A2, B1, and B2 banks' EPICs records can be changed at will during observing.

TITLE: 01/14 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Commissioning
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: USEISM
    Wind: 4mph Gusts, 3mph 3min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.45 μm/s
QUICK SUMMARY:

PEM and SUS charge measurements currently being taken. We've been Locked for over 5.5 hours. Today is an 8 hour maintenance day.

Workstations were updated and rebooted.  This was an OS packages update.  Conda packages were not updated.

TITLE: 01/14 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 162Mpc
INCOMING OPERATOR: TJ
SHIFT SUMMARY:

IFO is in NLN and OBSERVING as of 04:47 UTC

Smooth shift with one Lockloss caused by the ETMX glitch (alog 82254)

Per Ryan C's instruction from Ryan S, I also adjusted the PSL ISS Ref signal (attached pic) to bring the refracted power above 4.

There was one SDF Diff that I accepted (also attached).

LOG:

None

Lockloss likely caused by the ETMX glitch. EX L2 OUT channel shows erratic movement 170ms pre-lockloss (attached screenshot)

Bright beam spot on HAM3 ballast mass baffle moves with ITMY compensation plate yaw motion

We have been looking for the source of the scattering noise that varies  with the ITMY compensation plate yaw setting (80499). I recently searched for beam spots in the HAM3 area that move as CPY is yawed, using movies that I took from both the MC2 camera viewport and the PR2 camera viewport near HAM2.  Anamaria and I had done some of this before (77631) but this time I recorded the CP movements on the audio track of the movies for a more precise correlation. And I also modified the movies in iMovie to increase visibility of faint spots. Figure 1 shows that I did find a spot that moved precisely with CPY Yaw settings (link to movie clips: https://youtu.be/FDdNDPoQadU ). The spot appears to be on a ballast mass baffle (see Fig. 1), which is not angled as much as the scraper baffle (which I think the beam is supposed to fall on (Alena's slides)) and may thus retroreflect more light.

Mystery  beam spot on HAM3 spool piece comes from ITMX direction, not HAM2 direction

I had previously misinterpreted the pattern of light on edges and bellows of the HAM3 spool piece as suggesting that the mystery beam spot (78192) was coming from the HAM2 direction . More recently I found that there was light on the HAM3 side of the MC baffle that had a similar interference pattern and was consistent with being part of the mystery beam spot (Figure 1). The light on the HAM3 side of the baffle was visible when looking through the viewport for the PRM camera at a high angle. Thus, the beam is most likely coming from the ITMX direction, travelling close to the –Y wall of the beam tube.

One possibility is that it actually comes from ITMX, either scattered light from ITMX or scattered light from the back side of MC2 reflecting off of ITMX. Figure 3 shows these suggested paths and a picture taken from the point of view of the beamspot on ITMX that shows that there is a clear path to the site of the mystery beam spot. I think that the cartoon shows that it would be worth using a real model to determine if these paths are possible.

I checked to see if the beamspot on the eye baffle moved or modulated when I actuated the compensation plates. I made movies as I moved the two compensation plates more than 600 microradions in pitch and yaw, but, unlike the spot on the ballast mass baffle, I did not see any modulation or motion of the spot on the eye baffle.

TITLE: 01/13 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 160Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: The bottom monitor of NUC31 looks pretty dim today, we've also had a standdown query failure on OPS_OVERVIEW. The failure is from the last query being greater than 4 minutes from the current time, the last query was 01/11/25 15:25 UTC. We've been locked for 6 hours, range coherence check yielded.
LOG:                                                                                                                                                                                                                                             

• 16:48 UTC I adjusted the OPO temp while relocking.
• 17:03 UTC TRANSITION_FROM_ETMX lockloss
• 18:29 UTC NLN and start of Commissioning
• 19:37 UTC SEI to CALM
• 19:44 UTC Observing after wrangling some SDFs

TITLE: 01/14 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 162Mpc
OUTGOING OPERATOR: Ryan C
CURRENT ENVIRONMENT:
    SEI_ENV state: USEISM
    Wind: 6mph Gusts, 4mph 3min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.52 μm/s
QUICK SUMMARY:

IFO is in NLN as of 19:20 UTC (5hr 30 min lock)

Sheila, Jennie W

During commissioning window today we measured the P2L and Y2L gains for the PR2 mirror.

This is part of the work to understand how to move the beam on PR2 in order top avoid a reflection and subsquent stray beam off the PR2 scraper baffle (as found in alog #77631 by Annamaria and Robert).

The P2L gain was close to optimised and has been left at -0.36.

The commissioning window ran out before I could finish optimising the Y2L, I have left it at -7.00 which gave better A2L decpupling than the previous value.

Method:

• Inject line on PR2 M3 stage pitch at 30Hz using the OSC 9 filter bank in the ADS.
  • sitemap-> ASC -> Dither overview
• Check the PIT9 filter bank at the bottom of the page is not being used (CLK gain = 0).
• Set the matrix at the right of the row to have a 1 in the PIT9 to PR2 cell.
• Check there is a ramp time in the PIT 9 filter bank.
• Set the frequency to 30 and step the amnplitude to 1 in a couple of steps.
• Measure a reference for DARM and PRCL. The red and blue traces show the case when injecting into pitch with nominal A2L gains.
• Set the aevraging to exponential and zoom in on the line.
• Change gain in HzTS->PR2-> M3 DRIVEALIGN->P2L

 Do this until the line height relative to the background is minimised, allowing time for the ramp and a couple averages each step. One thing to note is that the line height above the background in the PRCL spectrum (LSC-PRCL_OUT_DQ) is much less than the relative height above the background in DARM which suggests that the noise in PRCL is not coupling strongly to DARM.

Switch off the line and set the PIT 9 amplitude to 0 counts.

Then repeat the above for the YAW 9 oscillator channel in the ADS, changing the gain in the Y2L gain filter bank in order to minimise the line height. The reference values for yaw are in the photo linked above with the green line showing DARM (we had gone into NLN cal meas with SRCL FF switched off for Elenna's SRCL tests so that is why DARM shows elevated noise). The orange line is the reference value of PRCL using the nominal Y2L gain. The same amplitude was used in the oscillator for this line but it was much higher above the PRCL background noise than for the pitch degree of freedom.

Template is at /ligo/hom,e/jennifer.wright/git/2025/A2L/20250113_A2L_PR2.xml