TITLE: 02/12 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Lock Acquisition
INCOMING OPERATOR: Oli
SHIFT SUMMARY:

IFO is in NLN and OBSERVING as of 05:58 UTC

Pretty quiet shift with one EQ caused Lockloss (alog bla bla)

We also dropped out of OBSERVING briefly since SQZ unlocked. The SQZ_OPO_LR was not reaching its count threshold of 80. Following this wiki page, I first attempted to change the SHG temperature in order to increase the SHG power, which was indeed reduced compared to Lock Acquisition time. This did not work, so I ended up reverting my -0.015C change and just set the threshold from 80 to 74 in SQZ params, which did end up working. After this, I retuned the opo temp, which prompted SQZ to automatically re-lock. After SQZ ANGLE guardian optimized the angle, we were able to get back into Lock. There were no SDFs to accept before going back to OBSERVING. Total troubleshooting/outage time was 40 mins, from 02:21 UTC to 03:01 UTC.

LOG:

None

Earthquake caused Lockloss (very local 4.6)

TITLE: 02/12 Eve Shift: 0030-0600 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Observing at 154Mpc
OUTGOING OPERATOR: TJ
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 9mph Gusts, 4mph 3min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.42 μm/s
QUICK SUMMARY:

IFO is in NLN and OBSERVING as of 21:26 UTC

Gerardo, Jordan, Camilla 

We disassembled ASSY-D1700340-001 (installed in 39957, removed in 60667) with the plan of re-cleaning the VAC surface and reusing the metal parts with new DAR ZnSe in the upcoming vent. 

Sadly I chipped the 0.5" thick D1700340 window when removing it, photo, will add a note to the ICS record. The dust damaged the in-vac o-ring so we threw away the pair of o-rings but have spares in the LVEA TCS cabinets. 

D1700338 is at C&B, other parts are stored in the PCAL lab VAC storage and the ZnSe will be placed in the LVEA TCS cabinets.. 

Gerardo notified me earlier today he observed an abnormal noise and some wetness coming from the Y+ chilled water pump. When Eric and I arrived we more or less observed the same. It is most likely another failed pump seal which will have to be replaced. One will be ordered shortly assuming demand has lifted and there is available inventory. Pumps were swapped and no interruption to temperatures should be seen.

E. Otterman T. Guidry

Matthew, Camilla

Today we went to EX to try and measure some beam profiles of the HWS beam as well as the refl ALS beam.

Without analyzing the profiles too much, it seemed like (at least the HWS beam) matches previously taken data from Camilla and TJ.

The ALS beam still has the same behavior as reported a few years ago by Georgia and Keita (alog 52608), could not find a referencing alog) who saw two blobs instead of a nice gaussian, just as we see now

TITLE: 02/11 Day Shift: 1530-0030 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Observing at 156Mpc
INCOMING OPERATOR: Ibrahim
SHIFT SUMMARY: The shift started with the IFO unlocked. I kept it down since we had a full 4 hours of maintenance planned for the day. Relocking presented a few odd ALS issues, but Sheila managed to figure it out (see below). Other than that it was smooth relocking and we have now been observing for and hour.
LOG:

• Relocking notes:
  • Couldn't get ALSX arm power much above 0.6, even though the camera spot looked nice and round. Sheila ended up moving ITMX a bit to get the power up higher, but we still aren't sure why the camera doesnt quite agree. The rest of initial alignment was smooth.
  • ALS WFS autocentering wasn't on when we were starting main locking, even though it was locked and the WFS were engaged. Turning it on brought the WFS to work properly and the arm power raised a bit.
  • Sheila went out to ISCT1 to asjust the POP_X alignment before we went to DC Readout
• 2126 Observing

I made two minor changes to these nodes today:

1. Certain states now check if the Beckhoff locking thinks we have unlocked and the Gaurdian node will then go back to LOCKING. This is a continuation from alog81870.
2. Changed all nds calls to use the call_with_timeout wrapper to avoid any potential hangs.

The POP X PZT was railed after yesterday's PR2 spot move, so Jennie and I went to the table and relieved it using the steering mirror right after the the pZT.

Elenna is looking for some information about the POP X path, so Jennie W and I took this photo and added optic labels to it.

All maintenance day activities have finished and we just got back to observing at 2126 UTC.

WP 12327. This is for the work Aidan is doing looking at LVEA temperature vs range (LLOalog#74999). 

• Photos attached on the HWS table: HWS X, HWS Y, Lenses. 
• Photos attached on the CO2X table: laser, periscope, beamdump
• Photos attached on the CO2Y table: laser, periscope, beamdump

This morning, prior to sunrise, zone 2A in the LVEA experienced a rapid temperature decline. This was partially due to broken heating elements which prevented the duct heater from producing as much heat as it needed to. I have replaced the broken elements. 

The LVEA has been swept following maintenance, nothing really of note.

The POP-X readout chain has been moved from 45.5MHz to 36.4MHz. All RF chains have been checked and they look fine.

H1:ASC-POP_X_RF_DEMOD_LONOM was changed from 24 to 23.

I took a look at the locklosses during the calibration measurements the past week. Looking at DARM right before the locklosses, both times a large feature grows around ~42 Hz right before the lockloss. Sat LL Thur LL

Thursday:

DARM_IN was dominated by the 42 Hz long oscillation and a ~505 short oscillation until the LL, DARM_OUT was dominated by the harmonic of the violins ~1020 Hz.

Saturday:

DARM_IN had a long and a short oscillation, the fund violin modes, ~510 Hz and ~7.5 Hz, DARM_OUT was dominated by the harmonic of the violins ~1020 Hz

I'm not sure how to/where to see exactly what frequencies the simulines were injecting during and before the lockloss.

Sheila, Matt Todd

We are having more incidences of the nonstationary noise 20-60 Hz that correlates with the CO2 ISS channel. 

Here's a collection of links related to this issue in the past: 

• Derek lasso run for time of sudden turn off: 81764,
• detchar git issue 306
• detchar git issue about running lasso for max: 246
• detchar git issue when sqz seemed to be involved in this noise: 237
• correlation with filter cavity control signal 78485
• Last May noise seemed to go away when the squeezer was blocked: 78033
• Other alogs from last May, this seemed urelated to PR3 moves but did happen at the same times: 77980

Here is a Lasso result for the noisy lock from this weekend: lasso Feb 9. Jane Glanzer is working on running lasso for some of the recent noisy times including the max as well as mean channels, so that may provide additional clues. We still see the ITMX CO2 ISS channel correlated with range.  Note, on Feb 7th Lasso chooses  H1:IOP-OAF_L0_MADC2_EPICS_CH15 which is the same thing as ITMX_CO2_ISS_CTRL2_INMON,

For the 9th the Rayleigh statistic also clearly shows this issue: summary page for Feb 9th, but comparing this to one of our normal days (range just below 160 and stable on Feb 4th) we also see nonstationarity at these frequencies.  So, it is possible that we normally have this non stationary noise at a lower level and it is always limiting our sensitivity.

Feb st we had an incident where the ISS CO2 channel was correlated with the range, screenshot.  Feb 1st there was also a remarkable change in the FC length control signal peak to peak, which has not shown any correlation with these range drops in the last week and a half, but did last may (78485).  Matt found this alog about squeezer issues on the 1st, 82581, we adjusted the SHG temperature, and fiber polarization, and there was a temperature excursion in the FCES. The FC length control signal was noisy from Jan 2nd to Feb 1st, and has been back to normal since. 

Operator request:  If operators see the range fluctuating with lots of noise between 20-40 Hz, (similar to Feb 9th), could you drop out of observing and go to no squeezing for 10 minutes or so?  We would like to see if this problem comes and goes with squeezing as it did last May. 

Sheila and I are continuing to check various PD calibrations (82260). Today we checked the POP A LF calibration.

Currently there is a filter labeled "to_uW" that is a gain of 4.015. After some searching, Sheila tracked this to an alog by Kiwamu, 13905, with [cnts/W] = 0.76 [A/W] x 200 [Ohm] x 2¹⁶ / 40 [cnts/V]. Invert this number and multiply by 1e6 to get uW/ct.

Trusting our recalibration of IM4 trans, we have 56.6 W incident on PRM. We trust our PRG is about 50 at this time, so 2.83 kW are in the PRC. PR2 transmission is 229 ppm (see galaxy optics page). Then, the HAM1 splitter is 5.4% to POP (see logs like 63523, 63625). So we expect 34 mW on POP. At this time, there was about 30.5 mW measured on POP according to Kiwamu's calibration.

During commisioning this morning, we added the final part of the ESD glitch limiting, by adding the actual limit part to ISC_LOCK. I added a limit value of 524188 to ETMX_L3_ESD_UR/UL/LL/LR filter banks, which are the upstream part of the 28 bit dac configuration for SUS ETMX. These limits are engaged in LOWNOISE_ESD_ETMX, but turned off again in PREP_FOR_LOCKING.

In LOWNOISE_ESD_ETMX I added:

            log('turning on esd limits to reduce ETMX glitches')
            for limits in ['UL','UR','LL','LR']:
                ezca.get_LIGOFilter('SUS-ETMX_L3_ESD_%s'%limits).switch_on('LIMIT')

So if we start losing lock at this step, these lines could be commented out. The limit turn-off in PREP_FOR_LOCKING is probably benign.

Diffs have been accepted in sdf.

I think the only way to tell if this is working is to wait and see if we have fewer ETMX glitch locklosses, or if we start riding through glitches that has caused locklosses in the past.