WP 11173

Issues reported with EY temperature channel H1:PEM-Y_EBAY_RACK2_TEMPERATURE. With fence work ongoing this morning, we swapped cabling for Rack1 and Rack2 sensors on the EtherCAT End Link Chassis. This will help us determine if issue stays with Beckhoff channel or sensor. I did note that the M12 connector threads on port 1 seems to striped. Connector will need to be replaced.

Time cables were swapped: 10-10:30 am

J. Kissel, R. Savage

After Rick and I conversed about the systems level compromises in play (see LHO:69175) when placing the newer 410.2 Hz PCALX line near the 410.3 Hz PCALY line for comparisons like that in LHO:69290, we agree to push forward with the plans discussed in LHO:69175:
    (1) Move the PCALX 410.2 Hz PCALXY comparison line further away from the pre-existing PCALY 410.3 Hz TDCF line. Joe, for entirely different reasons, recommends 0.5 Hz separation instead of 0.1 Hz. THIS ALOG

        The new frequency is H1:CAL-PCALX_PCALOSC2_OSC_FREQ = 409.8 Hz.
     
    (2) Update the "DARM Model transfer function values at calibration line frequencies" EPICs records for the PCALX 410.2 Hz line, NOT YET DONE, SEE BELOW
    (3) Revert all DEMOD the band-passes to have a pass band that's +/- 0.1 Hz wide (what we had in O3)      DONE ALREADY, and now for 410.3 Hz: see LHO:69265 and THIS ALOG
    (4) Revert all DEMOD I & Q low passes to a 10 second time constant, or 0.1 Hz corner frequency           DONE ALREADY, and now for 410.3 Hz: see LHO:69265 and THIS ALOG
    (5) Change COH_STRIDE back to 10 seconds to match the low pass, and Change the BUFFER_SIZE back to 13.0 in order to preserve the rolling average of 2 minutes. DONE ALREADY, and now for 410.3 Hz: see LHO:69265 and THIS ALOG

I've also modified the three band-pass filters in the SIG banks of the special segregated PCALX DEMOD for the PCALXY comparison (i.e. H1:CAL-CS_TDEP_PCAL_X_COMPARE_PCAL_DEMOD_SIG, _EXT_DEMOD_SIG, _ERR_DEMOD_SIG). These had had a pass pand with of 0.01 Hz, so I've created a new band pass for 409.8, butter("BandPass",6,409.79,409.81). It lives in FM1, and I've copied the old band for 410.2 Hz pass over to FM2.

In order to have *all* of our ducks in a row with the line move, we still need to do:
    (2) Update the "DARM Model transfer function values at calibration line frequencies" EPICs records for the PCALX 410.2 Hz line,
but that also means we need to do a step not listed above
    (0) Update the pydarm_H1.ini file to reflect that the pcalx comparison line is now at 409.8 Hz, and
    (6) Let the GDS team know that there's a calibration line frequency change and they need to update the GDS line subtraction pipeline.

This line frequency change is in play as of 2023-05-04 00:20 UTC.
Stay tuned!

Here's the latest list of calibration lines:
Freq (Hz)   Actuator               Purpose                      Channel that defines Freq             Since O3
15.6        ETMX UIM (L1) SUS      \kappa_UIM excitation        H1:SUS-ETMY_L1_CAL_LINE_FREQ          Amplitude Change on Apr 2023 (LHO:68289)
16.4        ETMX PUM (L2) SUS      \kappa_PUM excitation        H1:SUS-ETMY_L2_CAL_LINE_FREQ          Amplitude Change on Apr 2023 (LHO:68289)
17.1        PCALY                  actuator kappa reference     H1:CAL-PCALY_PCALOSC1_OSC_FREQ        Amplitude Change on Apr 2023 (LHO:68289)
17.6        ETMX TST (L3) SUS      \kappa_TST excitation        H1:SUS-ETMY_L3_CAL_LINE_FREQ          Amplitude Change on Apr 2023 (LHO:68289)
33.43       PCALX                  Systematic error lines       H1:CAL-PCALX_PCALOSC4_OSC_FREQ        New since Jul 2022 (LHO:64214, LHO:66268)
53.67         |                        |                        H1:CAL-PCALX_PCALOSC5_OSC_FREQ        Frequency Change on Apr 2023 (LHO:68289)
77.73         |                        |                        H1:CAL-PCALX_PCALOSC6_OSC_FREQ        New since Jul 2022 (LHO:64214, LHO:66268)
102.13        |                        |                        H1:CAL-PCALX_PCALOSC7_OSC_FREQ           |
283.91        V                        V                        H1:CAL-PCALX_PCALOSC8_OSC_FREQ           V
409.8       PCALX                  PCALXY comparison            H1:CAL-PCALX_PCALOSC2_OSC_FREQ        New since Jan 2023, Frequency Change THIS ALOG
410.3       PCALY                  f_cc and kappa_C             H1:CAL-PCALY_PCALOSC2_OSC_FREQ        No Change
1083.7      PCALY                  f_cc and kappa_C monitor     H1:CAL-PCALY_PCALOSC3_OSC_FREQ        No Change
n*500+1.3   PCALX                  Systematic error lines       H1:CAL-PCALX_PCALOSC1_OSC_FREQ        No Change (n=[2,3,4,5,6,7,8])

We just had another PI lockloss from ETMX mode 24, at 10.431 kHz, at Hour 1:36 in the lock. This occured as the HOMs were thermalized through the PI forest there. I have now reverted + loaded SUS_PI guardian changes from LHO:69219, when I raised the RMS monitor damping thresholds by 2-5x. RMS monitors to trigger damping are now back to their "normal" low values. GRD changes have not yet been SVN'd.

I tried to manually damp mode 24 after it had rung up that high, but I didn't stumble onto any phases or increased/decreased damping gains that brought the mode down in time. Elenna tried to turn omc_whitening off to buy us more time for pi-damping, which I think helped but it was likely too late. I'm not sure why we can't damp the rung up 10.4kHz mode, but for now I am lowering the RMS thresholds to engage PI damping to what they were before, when we had mitigated PI locklosses for quite a while.

Thu May 04 10:05:14 2023 INFO: Fill completed in 5min 14secs

Gerardo confirmed a good fill curbside.

We are experimenting with filling in the morning before the sun has had time to heat up the outside dewar and raise the head pressure (which increases the LN2 spill and lowers the thermocouples starting temperatures). For example, TC-A starting temperature yesterday was -67C and today is -42C.

To make the SDF Diff number stand out from its neighbouring Test Point Counts, I have changed its colour scheme on the CDS Overview.

Following TJ's suggestions, the SDF DIFF colours differ between safe.snap and OBSERVE.snap references.

TITLE: 05/04 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 9mph Gusts, 7mph 5min avg
    Primary useism: 0.02 μm/s
    Secondary useism: 0.19 μm/s 
QUICK SUMMARY:

- IFO has been locked for 0:25 minutes upon arrival

- Switched to COMMISSIONING mode due to a few SDF observe differences - seem to be all SQZ related - Tagging SQZ, Screenshots below

- Noticed the FC2 M3 SUS is railed, later diagnosed to have come from SQZ_FC tryng to FIND_IR

- CDS/SEI/DMs ok

TITLE: 05/04 Eve Shift: 23:00-07:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Locking
SHIFT SUMMARY: Spent most of the eveving with the IFO locked, did some OMC alignment and Louis did Calibration work. Lost lock from CSOFT ring up and IFO is currently locking at AQUIRE_PRMI
LOG: Louis may do more calibration if we get back to NLN.

• SUS
  • Accepted filters changes for ETMY mode 16. Looked like this mode hasn't been damped for 20+ days and copied the other undamped modes filters. sdf screenshot
  • Accepted filters changes for ITMX mode 19. Turned on FM3 (+30deg) to be total of +270deg curemt gain 0. sdf screenshot
• CAL
  • On is explained in Jeff's alog 47429 to mean that HWINJ is going to end X 

Camilla, Vicky

Walking OMC ASC QPD offsets as before in LHO:67994, now that TCS and IFO has settled more, and the junk light level going from IFO --> OMC has changed (down to ~1.7mW from 5mW LHO:68177).

Starting from Koji's saved values from then:

caget H1:OMC-ASC_QPD_{A,B}_{PIT,YAW}_OFFSET:
H1:OMC-ASC_QPD_A_PIT_OFFSET    -0.285
H1:OMC-ASC_QPD_A_YAW_OFFSET    -0.145
H1:OMC-ASC_QPD_B_PIT_OFFSET    -0.17
H1:OMC-ASC_QPD_B_YAW_OFFSET    -0.05

We walked OMC ASC QPD offsets in the same range as Koji did before, looking at his offsets table, and saw similar %-level changes in the optical gain, mianly reductions. This is expected if our alignment is the same.

Camilla was hopeful (attached trend) that the below settings were an improvement but after holding for 20 minutes at these and then reverting to the above nominal settings, the difference is <0.5% (see attached plot) so no changes have been saved.

H1:OMC-ASC_QPD_A_PIT_OFFSET    -0.265
H1:OMC-ASC_QPD_A_YAW_OFFSET    -0.145
H1:OMC-ASC_QPD_B_PIT_OFFSET    -0.145
H1:OMC-ASC_QPD_B_YAW_OFFSET    -0.1

IFO has been locked for 3h45. Calibration team has done some measurements and I am currently slowly adjusting OMC alignment (repeat of Koji's alog67994).

Naoki, Patrick, Jenne

On last Sunday, the ETMX camera was restarted and its exposure was changed from 500 to 10000 by the ini file, which caused the camera servo issue. To avoid this, we changed the ETMX/ETMY camera exposure in the ini files. The BS camera exposure in the ini file is good for camera servo.

The ini files for ETMX/ETMY/BS camera are stored in following place.

ETMX: /opt/rtcds/ifo/lho-pylon-camera-config/H1-VID-CAM-ETMX.ini
ETMY: /ligo/cds/lho/h1/camera/H1-VID-CAM27.ini
BS: /ligo/cds/lho/h1/camera/H1-VID-CAM26.ini

The camera exposure we set in the ini file is as follows. The original exposure in the ini file was 10000.

ETMX: 500
ETMY: 3500
BS: 10000

To load the updated ini file, the camera needs to be restarted. We should restart ETMX/ETMY camera when the camera servo is OFF.

Jennie, Jenne, Vicky

As part of a larger suite of optimisations today, the interferometer was taken out of observing and we tried to optimise the H1:LSC-SRCL1_OFFSET to remove the SRC detuning (optical spring).

I took these measurements yesterday, and as a result Jenne agreed that the higher we could push the OFFSET to negative side, the better.

But, that this is not possible for stable operation as it will not give us enough control range before the photodiode readout saturates (at 32000 counts).

I noted yesterday that our largest offset gave us a huge reading on the POP REFL 45 PD ( H1:LSC-POP_A_RF45_I_INMON ) ~ 27 000 cts.

Therefore we will aim to push no further than 22 000 counts for either H1:LSC-POP_A_RF45_I_INMON (in phase PD readout) or H1:LSC-POP_A_RF45_Q_INMON (quadrature phase PD readout).

Changing the SRCL1 offset to -200 gives us a reading on the photodiode of around -22761 cts for the in phase readout and -5499 cts for the quadrature phase readout.

The first pdf attached shows the results for the -200 count SRCL1 offset, and the second one for the previously used SRCL1 offset value of -165 counts.

It can be seen from the ssensing function plot (last image in both pdfs) that the -200 count measurement appears flatter at low frequency.

After this point I handed over to Vicky to optimise squeezing.

The following measurements were taken after the DARM offset was changed from 20mA to 40mA. And the same set of graphs is attached below for each.

SRCL1 offset is now -200 counts.

We just had a lockloss after 20.5 hours of lock that appears to be from the ASC, specifically CSOFT P. The oscillation was at about 0.45 Hz and the ring up occurred within the last two minutes of lock. The oscillation appears in other ASC signals, such as INP1, DHARD, and MICH.

I am suprised to see this kind of lockloss so long into the lock, so I am not exactly sure what action to take. I have increased the DSOFT P and CSOFT P gain to give more bandwidth to the loops. I also think we should try to get an OLG of CSOFT P at this higher power (the last OLG was taken at 60W, 67539). OLGs of all arm ASC loops at 430 kW of power would be ideal, but take time.

Austin, Betsy, Karla, Rahul

We have finished bonding fused sillica Ears to ETM12 using Hydroxide Catalysis Bonding (HCB) technique, please see pictures attached below for reference. The ear-test mass bond layer has few air bubbles within our tolerance (less than 50 sq mm of the total bond area). We can confirm that the position of both the ears on the two flat surface of the mirror are within the required +-0.1mm.

ETM12 (also see galaxy page for details on the optic) is a our spare test mass mirror between the two sites. The details of the ear and test mass mirror is given below,

- Ear s/n 30077403-04 (Q2300015) is bonded to the flat side S3.

- Ear s/n 30077403-05 (Q2300016) is bonded to the flat side S4.

Both the ears were 22.3 grams heavy (measured using a calibrated scale in a clean room).

The fiducial line measurements on the optic was performed at CIT and the details are posted in E2200356_v1.

I have uploaded the latest version V27 of Jig settings calculation on the DCC.

We still need to measure the total weight of the optic and apply First contact to clean the HR side.

Jennie, Camilla, Vicky

I used Craig and Camilla's code in /ligo/gitcommon/noise_recorder to measure the DARM OLG and the PCAL to DARM TF in order to look at the SRC detuning over thermalisation and whether we can change it.

To measure the DARM TF use:

darm_noise_injection_caller.py

but change the common_name_prefix to reflect your specific measurement (ie. SRCL1 offset).

pcal_noise_injection_caller.py

but change the common_name_prefix to reflect your specific measurement (ie. SRCL1 offset).

darm_sensing_function_processor.py

make sure the .hdf5 filenames for the pcal and darm measurements are correct, and make sure you have updated date_str to reflect the correct date and label_prefix to reflect the common name label of the two measurements. Also copy across the PCAL measurement to the DARM measurement folder as these will have been saved separately due to different time stamps. Then change date_dir_str to the name of the DARM measurement directory. I just made a new process_sensing_function_measurement() function in the script for each measurement I had to do.

Posting this now to show measurements taken. Will comment tomorrow with all graphs on one plot.

Attached to the report are the compiled plots from both measurements, which are in the data folders listed in the table.

J. Kissel

As a result of our improved sensitivity below 30 Hz since O3, and recently exposed deleterious bi-linear coupling between these calibration lines and excess QUAD reaction chain motion at 3.4 Hz (LHO:68003), I've reduced the amplitude of the 15-17 Hz calibration lines.

Channel that defines the amplitude      Former        Now        Reduction Factor
H1:SUS-ETMX_L1_CAL_LINE_CLKGAIN           75.0        20.0       3.75x
H1:SUS-ETMX_L2_CAL_LINE_CLKGAIN          120.0        35.0       3.42x
H1:SUS-ETMX_L3_CAL_LINE_CLKGAIN            1.0         0.3       3.33x
H1:CAL-PCALY_PCALOSC1_OSC_SINGAIN       1000.0       250.0       4.00x

The metric I used to judge by how much I could decrease the amplitude is the front-end computed coherence-based uncertainty in the transfer function between each line excitation and DARM_ERR. Prior to this change, the uncertainty had been hovering around 0.001 or below, i.e. 0.1% or below. We don't need *that* amazing of uncertainty. Recall, when we set the line heights during O3, we were shooting for a compromise between "the uncertainty on the time dependent correction factors derived from the calibration lines should be around 0.2% such that their uncertainty is negligible w.r.t. the uncertainty in the rest of the full response function systematic error budget" and "don't drive any harder than you need to; these loud lines cause bilinear coupling that degrades the sensitivity."

The first attachment shows a trend of the coherence, individual line uncertainty, TDCF uncertainty, and calibration line amplitude during the tuning. Note that as I began to close out my tuning, we began experiencing a mild earthquake, which is also useful information. Indeed, during that earthquake, the uncertainty didn't really get worse that 0.4%, which is fine.

Also, as a result of recent review of the frequencies of the new PCALX calibration lines which constantly monitor the systematic error (LHO:68139), I've changed the frequency of the 56.39 Hz line to 53.67 Hz, squarely in the middle of the non-vetoed region between [51.59, 54.69) Hz.

All of these changes have been in place since Mar 30 2023 18:00:00 UTC (GPS 1364234418, Mar 30 2023 11:00:00 PDT).

Here's the new list of calibration lines:
Freq (Hz)   Actuator               Purpose                      Channel that defines Freq             Since O3
15.6        ETMX UIM (L1) SUS      \kappa_UIM excitation        H1:SUS-ETMY_L1_CAL_LINE_FREQ          No Frequency Change, Reduced Amplitude
16.4        ETMX PUM (L2) SUS      \kappa_PUM excitation        H1:SUS-ETMY_L2_CAL_LINE_FREQ          No Frequency Change, Reduced Amplitude
17.1        PCALY                  actuator kappa reference     H1:CAL-PCALY_PCALOSC1_OSC_FREQ        No Frequency Change, Reduced Amplitude
17.6        ETMX TST (L3) SUS      \kappa_TST excitation        H1:SUS-ETMY_L3_CAL_LINE_FREQ          No Frequency Change, Reduced Amplitude
33.43       PCALX                  Systematic error lines       H1:CAL-PCALX_PCALOSC4_OSC_FREQ        New since Jul 2022 (LHO:64214, LHO:66268)
53.67         |                        |                        H1:CAL-PCALX_PCALOSC5_OSC_FREQ        Updated as of this aLOG
77.73         |                        |                        H1:CAL-PCALX_PCALOSC6_OSC_FREQ        New since Jul 2022 (LHO:64214, LHO:66268)
102.13        |                        |                        H1:CAL-PCALX_PCALOSC7_OSC_FREQ           |
283.91        V                        V                        H1:CAL-PCALX_PCALOSC8_OSC_FREQ           V
410.2       PCALX                  PCALXY comparison            H1:CAL-PCALX_PCALOSC2_OSC_FREQ        New since Jan 2023 (LHO:66967)
410.3       PCALY                  f_cc and kappa_C             H1:CAL-PCALY_PCALOSC2_OSC_FREQ        No Change
1083.7      PCALY                  f_cc and kappa_C monitor     H1:CAL-PCALY_PCALOSC3_OSC_FREQ        No Change
n*500+1.3   PCALX                  Systematic error lines       H1:CAL-PCALX_PCALOSC1_OSC_FREQ        No Change (n=[2,3,4,5,6,7,8])