Janos has requested these alarms be bypassed and PT243 temporarily disabled in VACSTAT. Full list is:
Bypass will expire:
Wed Aug 13 12:24:46 PM PDT 2025
For channel(s):
H0:VAC-LY_CP1_TE102A_DISCHARGE_TEMP_DEGC
H0:VAC-MX_X1_PT343B_PRESS_TORR
H0:VAC-MY_Y1_PT243B_PRESS_TORR
Closes FAMIS26544, last checked in alog86165
HAM2_CPSINF_H3 has increased lines just over 60Hz
HAM4 has some increased lines at high frequency
BS ST2 has increased lines at high frequency, V3 mainly.
Mon Aug 11 10:08:07 2025 INFO: Fill completed in 8min 3secs
Edgard, Ivey
A few weeks ago, Oli ran some tests on the SR3 Yaw estimator (see LHO: 85745 for results). Edgard and I did some math to see if the OSEM estimator is requesting drive as expected by theory (we want our theoretical plot to align with the yellow trace in the third plot in the pdf below).
Attached below are images of the theoretical drive estimates compared against the empirical drive requests (yellow trace). The "old" theoretical drive estimate is made with the old blend filters (see LHO: 84004), and the "new" theoretical drive estimate is made with the new blend filters (see LHO: 86265).
A few notes on how we calculated the theoretical drive estimate: Because OSEM noise dominates, except at the resonances where suspoint motion dominates, we only considered OSEM noise when generating our theoretical drive estimate. We multiplied the theoretical plot by 1/3, which we eyeballed. The difference of a factor of 3 is likely an error in our math, which we can easily check. The theoretical plot deviates significantly from the empirical results below 0.6 Hz because the OSEM noise data we are using is not ideal (see the first plot in the pdf for a more accurate depiction of OSEM noise). However, the main concern is to show that the general shape is accounted for.
What the theoretical drive estimate plots show:
The "old" plot shows that the peak at 2 Hz is expected. This peak is likely not noise as we had originally believed, but a part of a larger peak that consists of the peak at 2 Hz and its adjacent peak. For the yellow trace, the dip between the two peaks is a result of the suspoint motion dipping below OSEM noise. For the black trace, the dip between the two peaks is a result of not including suspoint motion in our math. The same can be said about the peak at around 3 Hz.
An objective of the new blend filters was to damp the 2nd and 3rd peaks, as well as make the peaks more symmetrical. The "new" plot shows the peaks are successful at request less drive, but the symmetry of the peaks has not changed significantly.
Overall, the theoretical drive plot shows that the major characteristics from Oli's test are accounted for by the theory, and the estimator is working as expected!
Jennie W
Francisco is helping me read data from the oscilloscopes we are using for the PD readout so we can measure a QPD to PD transfer function to figure out how the PDs are mis-aligned.
While he was working on this I went to re-align the input beam to the array as our last measurements of the coupling amplitude in the horizontal direction showed that the coupling was much larger than Shiva and Mayank had previously measured.
I found we could get better coupling with the input beam off in yaw on the QPD - I got this by moving the closest steering mirror to the input aperture in pitch and yaw (as these are both coupled slightly due to the QPD y and x axis not being perfectly aligned with the steering mirrors pitch and yaw directions).
Pictures I took are attached, photos one (showing AC voltage of PDs 1-4) and two (AC voltage of PDs 5-8) are only moving the steering mirror in yaw but the light went off the centre of the QPD too much (we expect it to be above 10000 counts but here it is ~6000), so I found another spot with less power drop on the QPD that still has pretty good alignment coupling to the PDs. For this latter spot I also included the photo of the QPD readout.
Photo 3 shows the QPD readout and the oscilloscope with the AC voltage values of PDs 1-4. The power on the QPD is about 9000 counts.
Photo 4 shows the oscilloscope with the AC voltage values for PDs 5-8.
Photo 5 shows the oscilloscope with the DC voltage values for PDs 1-4.
Photo 6 shows the oscilloscope with the DC voltage values for PDs 5-8.
Photo 7 shows the x, y and sum channels for the QPD on an oscilloscope.
We might have to move the QPD in yaw to centre it for this pointing into the PD array.
WP 12747
The negative rail power supply for ISC-R3 and ISC-R5 failed this morning. Fan seized and power supply tripped off. We opted to also replace the positive 18V since IFO was already down. When power was restored, we verified the fast shutter chassis HV was enabled. Control room reported issues with the PZT/shutter readback signals. On the floor we found the PZT driver chassis was powered off. Chassis was power on.
Rack ISC-C6 (U25-U27)
Power Supplies Removed: S1202017 and S1201944
Power Supplies Installed: S1201912 and S1201915
F. Clara, R. McCarthy, T. Sanchez
This Power Supply Failure did cause a lock loss.
we held in Check_AS Shutters due to this same power supply failure.
NLN reached by 17:21:50 UTC
Observing reached by 19:47:01 UTC
This morning the Well water tank located behind the carpenter shop was found to be nearly empty with under 1ft of water. At approximately 7:50am the Well water pump was energized and used to fill the tank back up. For noise and vibration considerations the well pump ran water from approximately 7:50am until 8:18am. The well tank is now full again.
TITLE: 08/11 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Aligning
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 4mph Gusts, 2mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.11 μm/s
QUICK SUMMARY:
H1 was down and trying to do an Initial_Alignment but saturating a number of suspensions, verbals warning about IFO_OUT from 14:17 UTC to 14:28 UTC so over 10 minutes of shaking the IFO OUT of the output arm.
I'm getting a persistent DIAG_MAIN message:
FAST_SHUTTER_HV: Fast Shutter HV not Ready
@ 1309 UTC Fast shutter channels:
H1:SYS-MOTION_C_SHUTTER_G_TRIGGER_VOLTS went to 3.877 V when it should have already dropped down to 0.5V or so.
H1:SYS-MOTION_C_SHUTTER_G_TRIGGER_POWER has increased to 1.9 mW when I'd expect it to go back down to 0
Both increased to levels that seem within the operational bound but not what their trends would suggest they should be operating at.
I cannot Close the fast shutter either.
H1:SYS-MOTION_C_FASTSHUTTER_A_READY says Busy.
Error Fault; Not Ready ; Not Closed.
Only CDS alarm this morning is the ongoing valved out PT343B at MX. I have extended its bypass to Wed.
Bypass will expire:
Wed Aug 13 08:05:06 AM PDT 2025
For channel(s):
H0:VAC-MX_X1_PT343B_PRESS_TORR
Earlier 6:08:34 UTC there was an 18V power supply that had stopped working which supplies power to multiple devices including the Fast Shutter infrastructure. The 18V power supply was reset and turned back on which should have powered back on the PZT driver that also gets power from the 18V supply. But the breaker on the back had been tripped.
It looks like shutter did close in that lockloss, which might have been caused by the power failure.
Attached are comparisons of a normal lockloss with that one.
TITLE: 08/11 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 155Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY:
IFO is in NLN and OBSERVING as of 04:48 UTC
Just got to Nominal Low Noise after a 5.8 EQ from Guatemala (lockloss alog 86288).
Otherwise, just the most uneventful of shifts. Relocking was fully auto and DRMI lock was swift post-earthquake.
LOG:
None
Earthquake caused lockloss. This was a 5.8 EQ in Guatemala.
Recently, I noticed that the mystery beam spot on the spool piece near HAM3 was much dimmer after the break this spring than in was before ( 85079) To see if this change may have been associated with the CP-Y move we made during the break, we swept through nearly the entire range of pitch and yaw (-300 to 300) while taking a video. The linked video (https://www.youtube.com/watch?v=DIwnx13NzEU&ab_channel=RobertSchofieldLIGO) shows the view from the MC2 camera viewport before the break and after the break. The drop in intensity over the break is quite obvious, but I can see no further change in intensity during the sweep. The sweep can be monitored in the video, both before the break and after, by the motion of the ghost beam spots on the ballast baffle below PR2 (on the center left of the image). The CP move during the break was larger than these sweeps, so it is still possible that the move during the break was the source of the drop in intensity.
However, another possibility is that the movement of the PR2 beamspot, and the reduction in clipping on the PR2 scraper baffle was the source of the drop in intensity. The last pictures I took of the mystery beam spot before the break were in January of 2025. After that, there were a series of moves of the PR2 beam spot and associated reductions in the intensity of the beam coming out the HAM3 viewport that were made in February of 2025 (82670, 82722, 82740, 82793), reducing the power in the beam that comes out of the viewport from about 17mW to about 3.5mW. The ”before” clip in the video below was made in December of 2024, when the HAM3 viewport beam was in the 17mW era, while the ”after” clip is at 3.5 mW, if we assume it is the same now as before the break (could be worth checking). If the ”mystery” beam spot comes from the edge of the scraper baffle (see figure), then the PR2 spot moves might have reduced its intensity, by a factor of about 5 if it is proportional to the light at the viewport.
The figure shows that there is a spot on the edge of the scraper baffle (which is only there when laser light is present) that seemed to get dimmer when the mystery spot got dimmer. The diagram shows how the reflection/diffraction would light up the wall of the spool piece as seen in the photographs. The edge of the aperture would be lit by the beam that is clipped and especially by the beam reflected off of the baffle to the viewport and reflecting back to the baffle.
TITLE: 08/10 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 152Mpc
OUTGOING OPERATOR: Tony
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 14mph Gusts, 7mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.11 μm/s
QUICK SUMMARY:
IFO is in NLN and OBSERVING as of Aug 9 22:42 UTC (25 hr lock!)
TITLE: 08/10 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY:
H1 has been locked for 25 hours.
No drops out of Observing, locklosses, or issues. Survived a 6.1 Mag earthquake from Turkey.
No Superevent Candiates either.
LOG:
| Start Time | System | Name | Location | Lazer_Haz | Task | Time End |
|---|---|---|---|---|---|---|
| 19:33 | SAF | Laser HAZARD | LVEA | YES | LVEA is Laser HAZARD | 11:33 |
| 21:07 | Tour | Ibrihim & Tour | Overpass | N | Leading a tour | 21:37 |
Sun Aug 10 10:07:12 2025 INFO: Fill completed in 7min 9secs
TITLE: 08/10 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 142Mpc
OUTGOING OPERATOR: Oli
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 8mph Gusts, 5mph 3min avg
Primary useism: 0.02 μm/s
Secondary useism: 0.09 μm/s
QUICK SUMMARY:
H1 has been locked and Observing for just over 16 Hours.
All systems seem to be running smoothly.
Superevent candidate S250810ck was announced right before I walked in to the control room.
An hour ago we had an interested earthquake that was pretty close but small enough that we didn't lose lock.
TITLE: 08/10 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 151Mpc
INCOMING OPERATOR: Oli
SHIFT SUMMARY:
IFO is in NLN and OBSERVING as of 22:42 UTC
As hoped, a very quiet shift in which we were observing for the whole time. Nothing else of note.
LOG:
None
Samantha Callos, Robert Schofield
There is a persistent peak at 20 Hz that has been appearing and disappearing intermittently for several months. I have found the times it existed corresponded to work hours during week days. Robert and I looked at the summary pages and DTT for the floor accelerometers and noted that the noise was most present in the area around YCRYO, we ruled out other locations around site and determined the source of the noise was coming from the Vacuum Prep Warehouse. We tested seismic isolation of the various HVAC units around the warehouse and found the Liebert AC unit inside the VPW which can manually be turned on and off and was moved there sometime in the last year.
I cycled through intervals of turning the Liebert unit off and on and checked the CS floor accelerometers for those times (see times below, Fig. 1, and blue arrows in Fig. 4). When the unit is off, the spike at 20 Hz in the accelerometers disappears. I then checked coupling to DARM and noted the noise at 20 Hz was present and that there was a harmonic at 40 Hz as well (see Fig. 2).
Additionally, for the external AC (Daikin), we noted that the springs it is mounted on are entirely compressed, so there is little to no seismic isolation for the entire unit. Noise from the previous unit has been found in DARM before (see alog 77477). The closest accelerometer to this HVAC unit is the YCRYO floor accelerometer and the shut down period can be seen in the spectrogram for it (see Fig. 3). It can also be seen automatically turning off and on the summary page 24-hour spectrogram (see Fig. 4). Comparing this shut down period to when it is on, it does not look like the noise is making its way into DARM for now, however, we recommend seismically isolating the Daikin as we have seen it couple to DARM before.
Liebert AC on/off times for 08-05-2025:
Liebert AC on/off times for 08-06-2025:
Liebert/Daikin on/off times 08-06-2025:
In the a-log 85984, we noted that in addition to the sharp line at 21.26 Hz in DARM there was also a ~1Hz broad feature around the 21.26 Hz line. At that time, it wasn't clear whether those two features were connected. Looking at the on/off times from this test, it seems they are connected. The first attached figure is the DARM (GDS STRAIN CLEAN) and the second figure is the LVEAFLOOR YCRYO accelerometer. The feature in accelerometer is sharp, while in DARM we see both the sharp as well as 1Hz broad feature. In the comment to the a-log 85984, we looked at different auxiallary and PEM channels to check if there are any other channels that show both these features. Among the channels we looked at, we saw both these featues in ASC-PRC1_{Y,P} signals. The third figure shows the spectrogram of ASC-PRC1_P_IN1_DQ during this on/off tests during which we see the sharp as well as ~1Hz broad feature in that channel. It is not clear whether this is just another witness of DARM feature or this is a place where it gets into the DARM.
The liebert unit was installed circa 2018. The outdoor unit was replace more recently.
I just want to add that we do not use PRC1 P/Y in loop in full IFO lock. However, the PRC1 error signal is the POP A DC signal from the POP QPD on HAM3. This means that the POP A QPD may be a good witness of this line, but is not the coupling source of the line.
