The Picket Fence display on Nuc5 was updated and restarted.  There were some minor code changes.  The only significant change was a switch from HWUD station back to HLID.

TITLE: 08/20 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 3mph Gusts, 1mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.07 μm/s
QUICK SUMMARY: Pumpdown of corner volume continues. Some light maintenance activities planned for the day as well.

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

Jordan V., Gerardo M., Travis S., Janos Cs.

The PT-154 MKS wide range gauge was replaced due to failure, on the small FCT section between HAM7 and BSC3. Its small volume is being pumped down. As the pressure of that FCT section between GVs FCV-1 and FCV-2 is supposedly around 1-2E-8 Torr, it will be pumped overnight. Now it is at 6.1E-8 Torr. Tomorrow it will be valved in to the main volume. After this, this small FCT section will be valved together with HAM7 and the relay tube (FCV-1 to be opened).

Leak check was also done, and no leak bigger than 1E-10 Torr was detected.

Naoki, Camilla.

After SQZ laser was turned on laser week, today we locked PMC and SHG with no issues. We struggled with OPO locking (CLF dual). In the end Naoki could lock by hand but the trigger wasn't triggering. We will continue to troubleshoot tomorrow.  The OPO dither lock  worked well but only after we swapped H1:SQZ-OPO_IR_LSC_SERVO_GAIN sign from -10 to 10: strange!

I put ZM4/5 PSAMS and ZM4/5/6, ZM2/3 and FC1 alignments back to the same values as in alog79193. Todays plot and July 17th plot attached. There was only around 0.3mW on the IR trans, when we expect 1mW. So may need some more alignment moved. We have the SQZT7 iris to help if needed.

TITLE: 08/19 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: Tony-ish
SHIFT SUMMARY:  HAM5 and 6 got unlocked today.
LOG:

14:30 In Corrective maintanence
16:00 HAM5/6 HEPI unlocked                                                                                                                                                                            

Camilla, Oli

We looked into the weird results we were seeing in the ITMX In-Lock SUS charge measurements. The coherence when the bias is on for both the bias and length drives is always good, but the coherences are bad (usually below 0.09) for both bias and length drives when the excitations run with the bias off.

I compared the differences in the coherence value outputs in the python script versus the matlab script(screenshot), and although the values are calculated slightly differently and are not exactly the same, they are resonably close enough that we can say that there is not an issue with how we are calculating the coherences.

Next, we used ndscope to look at the latest excitations and measurements from July 09th (ndscope-bais on, ndscope-bias off). Plotting L3_LOCK_BIAS_OUTPUT, L3_DRIVEALIGN_L2L_OUTPUT, L3_LVESDAMON_UL_OUT_DQ, and L3_ESDAMON_DC_OUT_DQ for both ITMX and ITMY, if there was an issue with the excitations not going through, we would expect to see nothing on the ESDAMON and LVESDAMON channels, but we do see them on ITMX.

We were still confused as to why we would see the excitations go through the ESDAMON channels but still have such low coherence, so we compared the ITMX measurements to ITMY on dtt for the July 09th measurements looking at how each excitation showed up in DARM and what the coherence was. When the bias was on, both the bias drive and Length drive measurements look as we expect, with the drive in their respective channels, a peak seen in DARM at that frequency, and a coherence of 1 at that frequency(bias_drive_bias_on, length_drive_bias_on). However, in the comparisons with the bias off, we can see the excitations in their channels for both ITMX and ITMY, but while ITMY has the peak in DARM like the bias on measurements, ITMX is missing this peak in DARM(bias_drive_bias_off, length_drive_bias_off). The coherence between DARM and the excitation channel is also not 1 on ITMX.

We showed these results to Sheila and she said that these results for ITMX with the bias off make sense if there is no charge built up on the ITM, which would be the first time this has been the case! So there are no issues with the excitations or script thankfully.

We will be making changes to the analysis script to still run the analysis even if the coherence is low, and will be adding a note explaining what that means.

I've combined the existing Python and MATLAB scripts that are used for calibrating the PSL rotation stage into one cohesive, cleaner Python script: /opt/rtcds/userapps/release/psl/h1/scripts/RotationStage/CalibRotStage.py

The script takes two arguments to run the full process of sweeping the stage and running the calibration fitting: python CalibRotStage.py -m -c

To skip the rotation stage sweep or calibration fitting steps, simply omit the -m or -c arguments, respectively.

The full process for running a PSL rotation stage calibration now goes as follows:

• Take IMC offline and pause LASER_PWR Guardian
• Run the calibration script as stated above with both arguments
• Input the new calibration coefficients into the calibration medm and accept these in SDF
• Relock IMC and resume LASER_PWR Guardian

J. Kissel
IIET Ticket 31266

Conversations are still brewing about what to do about DuoTone timing signals showing up in DARM -- presumably through the OMC DCPD's ADC card (see LHO:77579). Recall that we've narrowed down the coupling mechanism to direct channel-to-channel cross coupling within the ADC (see LHO:78238). As such, one of the options on the table is to reduce the amplitude of the DuoTone timing signal, which is using 1/4 of the ADC channel's range at 5 [V_pp], rather loud, IMHO (see LHO:78218). 

Daniel and Erik did a whole bunch of work at the start of O4 to get the front-end-code computed ADC timing measure more accurately reporting and answer with a better algorithm in the front-end (see LHO:67693 and LHO:67545), so I figured I show the trend of a few important front-end's answers, since I haven't seen such a trend:
    (1) the h1omc0 segregated IO chassis which houses the GW DCPDs,
    (2) the h1lsc0 computer which *used* to house the DCPDs prior to O4.
    (3 & 4) the two end-station ISC computers which house, among other things, the PCAL systems.

The answers from the long-term trend: 
    (1) 0.12 +/- 0.035 or +/- 0.08 [usec]
    (2) 7.05 +/- 0.031 or +/- 0.06 [usec]
    (3) 61.6 +/- 0.15  or +/- 0.31 [usec]
    (4) 61.6 +/- 0.15  or +/- 0.31 [usec]
where I'm eye-balling (via y-cursor at least) the long-term trend of the mean, the middle of the max/min excursions, and the worst of the max/min excursions.
These answers (the means) are all expected, but it's good to have some numbers on the max / min excursions, which are, presumably, noise.

Zoom in closer, one can see on the minute time scale trend of a gravitational wave event, the estimation of the timing error is about as precise.
     

R. Short, F. Clara

In the ongoing effort to mitigate the 9.5Hz comb recently found to be coming from the PSL flow meters (alog79533), this afternoon Fil put the PSL control box in the LVEA PSL racks on its own, separate 24V bench-top power supply. Once I shut down the PSL in a controlled manner (in order of ISS, FSS, PMC, AMP2, AMP1, NPRO, chiller), Fil switched CB1 to the separate power supply, then I brought the system back up without any issues. I'm leaving the ISS off for now while the system warms back up. I'm leaving WP12051 open for now until enough data can be collected to say whether this separate supply helps the 9.5Hz comb or not.

Please be aware of the new power supply cable running from under the table outside the PSL enclosure to behind the racks; Fil placed a cone here to warn of the potential trip hazard.

FAMIS 21224

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

FAMIS 21188

The PSL was taken down last Tuesday as part of Jason and Fil's comb hunt (alog79533), which shows in basically every trend six days ago.

The ISS was not turned back on when the PSL was brought back up last week, so Jason enabled it this morning, which explains the lower PMC transmitted power over the past week or so. However, even with the ISS now on, the PMC is putting out ~1.6W less power compared to before it was unlocked last week.

The FSS TPD has been trending down over the past several weeks and alignment looks poor on the camera, so sometime today or tomorrow I'll touch up the RefCav alignment.

About a week ago the PSL enclosure main-room Axis camera image froze mid-frame twice over two days in a row on the LVEA FOM machine (lveapslfom) but not on the control room FOM (nuc21).

Last night both the enclosure anti-room and main-room images on the control room FOM froze mid-frame but the LVEA FOM was fine.

In all cases I remote-desktopped to the machine and reloaded the web page to clear the error.

Mon Aug 19 08:09:15 2024 INFO: Fill completed in 9min 11secs

TITLE: 08/19 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: MAINTENANCE
    Wind: 4mph Gusts, 1mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.07 μm/s
QUICK SUMMARY:

Vacuum pressure in BSC3 around 2.04e-07 (need to be around 8.8e-8), so probably no gate valves today. Over the weekend an earthquake from Japan tripped the ISI watchdogs for ITMY, BS, ETMX, and ETMY. Those have been untripped by TJ.

FAMIS26004

Same as for the last time this was run (alog79474), the following seem elevated:

• ITMX St1 V1
• ITMY St1 V2
• ETMY ST1 H2

FAMIS26283

Laser Status:
    NPRO output power is 1.831W (nominal ~2W)
    AMP1 output power is 64.55W (nominal ~70W)
    AMP2 output power is 138.3W (nominal 135-140W)
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN
    PDWD watchdog is GREEN

PMC:
    It has been locked 5 days, 20 hr 28 minutes
    Reflected power = 20.62W
    Transmitted power = 105.1W
    PowerSum = 125.8W

FSS:
    It has been locked for 1 days 19 hr and 20 min
    TPD[V] = 0.5346V

ISS:
    The diffracted power is around 3.1%
    Last saturation event was 0 days 0 hours and 0 minutes ago

Possible Issues:
        AMP1 power is low
        PMC reflected power is high
        FSS TPD is low
        ISS diffracted power is high

I've lowered the alarm level for PT120B (BSC2) from 2.0e-06 to 2.0e-07. Two day trend of PT120 attached shows last nights excursion

Config:

Channel name="H0:VAC-LY_Y1_PT120B_PRESS_TORR" low="1.0e-10" high="2.0e-07" description="VE gauge, PT120B BSC2 CC"

Sun Aug 18 08:08:47 2024 INFO: Fill completed in 8min 43secs

Oli P, TJ S

Single Bounce AS_C level

To check that we can get light through to HAM6, we brought the IFO to the same alignment as in alog79193, where they also had HAM5,6 HEPI locked. We started with the fast shutter closed. With alignments the same we went into a single bounce configuration with ITMY aligned and went up to 10W. There was no light on AS_C initally, so Oli had to move SR2 about 200urads before there was light on the sensor. SR2 moved about 60urads to center on AS_C. With AS_C centered, H1:ASC-AS_C_SUM_OUTPUT was at 0.0078 vs the 0.0045 reported on July 17 reported in the linked alog above (73% increase). We ran into some P motion when we turned sensor correction on, but maybe this is expected while we have some HEPIs locked. The AS Air camera had the slightest bit of a spot on the top left corner of it when we were centered.

Fast Shutter Test

While centered on AS_C we opened the fast shutter. We immediately saw light on AS_A and AS_B (1600 and 2000 counts respectively). We closed the shutter and it went away. 1st attachment