TITLE: 05/05 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
SHIFT SUMMARY:

Calibration & Commissioning time (as well as some LVEA incursions) today.  With one seismic lockloss.  
LOG:

• 1510-2001 Crew heading out for Wind Fence work (will stop if weather gets sketchy)
  • 1635-1659 Checking to see if additional help needed (travis)
  • 1816-1852 Checking out wind fence (mike)
• 1516 Back to OBSERVING (after accepting filter diffs for L1_DAMP with ITMx & ETMy)
• 1519-2001 EY transitioned to Fence Work
• 1550-1602 Optics Lab cleans/checks (kim)
• 1618 Huge glitch seen on the running DARM dtt of nuc30 (all signals went up!)
• 1626 Running pydarm calibration measurement (corey,jeff)
• 1644 Verbal Alarm updated for lower-threshhold PI Mode alerts (ryanS)
• 1805 Pcal lab work (tony,dripta)
• 1806 LOCKLOSS
• 1815-1825 checking for water leaks in lvea (richard)
• 1819-1842 s/n checks (fernando, marc)
• 1819-1858 CER accel on PEM rack (marc, adrian)
• 1828-1834 dark measurements while we have seismic noise (elenna)
• 1830-1856 Turning on Hepta pump at EY (travis)
• 1835-1847 IMC WFS Centering (tj)
• 1953 back to NOMINAL LOW NOISE & taken to NLN_CAL_MEAS for calibration measurements (jeff)
• 2038 OBSERVING
• 2130 Picking up parts around EY wind fence---no operation of heavy machinery (randy,mitch)
• 2137 COMMISSIONING (jennie)
• 2218 Updating filter coefficients for PCal (rick)
• 2239 ISC_LOCK load by elenna

LOCKING NOTES:

• IFO locked before shift.
• 1806 lockloss (5.5hr lock) due to observed seismic motion (possibly 5.9 Japan eq? w/ 20min arrival time)
• For a dead PRMI, BS was moved quite a bit in negative PIT to get it to acquire (PRM pit in both directions didn't work & BS positive pit didn't help)
• Other than that, no other intervention required to get back to Nominal Low Noise (once seismic noise died down).

We have determined that 40 mA is a better DARM offset to operate at (more in-depth alog coming soon). I have added back in the guardian state "INCREASE_DARM_OFFSET" to the ISC_LOCK guardian. This state will occur between lownoise_length_control and damp_violins_full_power. We will increase the DARM offset to 40 mA in this state. This value is set in lscparams as DCPD_SUM_NLN. For lock acquisition, we will continue to use 20 mA, which is set via DCPD_SUM_TARG in lscparams. We will still have the OMC whitening off in this state, and the OMC_WHITENING state will still check the DCPD counts before turning on the whitening, in case we are in danger of saturation. If the violins are rung up particularly high, we might have to wait a little longer in OMC whitening now before we can proceed to NLN.

The guardian state uses a 5 second ramp time to increase the DARM offset.

Jennie, Jenne, Elenna, Vicky, Erik

As referred to in this entry we took a suite of measurements on the 3rd May to determine what changing the SRCL offset, DARM offset and turning off the whitening on DCPD would have on the sensitivity.

Measurement Order: from 05/03/2023

• Elenna measures contrast defect.
• Measure SCRL1 offset and optimise, see this entry.
• Vicky optimised squeezing.
• Elenna took BB PCAL > DARM measurement.
• Change DARM offset to 40 mA.
• SRCL1 offset measured and optimised.
• Elenna took BB PCAL > DARM measurement.
• DCPD whitening off.
• Elenna took BB PCAL > DARM measurement.
• Change DARM offset back to 20 mA

At low frequencies DARM looks better with 20mA offset, but we must remember that many things at low frequency are optimised for this DARM offset. See first plot for 20mA/40mA comparison.

The whitening ON/OFF (see second plot attached) does not look to have made a large difference to the sensitivity from these plots.

There is no coherence in the PCAL > DARM BB measurements we took at high frequency so to give us a good idea of the difference between 20mA and 40 mA DARM offset we will scale the DARM spectra using the one of the high frequency calibration lines.

Unfortunately, we did not spend any time in NLN with 40mA (just NLN CAL MEAS) so we will need to measure another DARM spectra in that state today.

The code I used to correct the DARM spectra with the PCAL to DARM measurements is in /ligo/home/jennifer.wright/git/DARM_offset

• Run_DARM_calib_20230503.ipynb runs the analysis.
• reference_times/reference_times_pre_O4.yml contains the measurement dictionary.
• Measurement data locations are listed in the table above.
• I used PCal_bb_inj_quick_cal.py by Craig to process the measurements but I had to alter it to use a DTT xml file reader that Erik wrote (reftf.py), as some of the TF measurements referenced in the .xml file were missing their B channels. Note: only an issue if you try to read directly from xml, I could still export the measurements as text files.

J. Betzwieser, D. Bhattacharjee, J. Kissel, R. Savage

Executive summary: More changes to calibration lines in order to commission the best answer out of the PCALXY comparison.

Based on the systems level compromises discussed on Friday last week about having the PCALX contribution to the PCALXY comparison right next to the 410.3 Hz PCALY line that's used for TDCFs (LHO:69175), I moved the PCALX comparison line from 410.2 Hz (0.1 Hz below 410.3 Hz) to 409.8 Hz (0.5 Hz below 410.3 Hz). LHO:69303. 

After looking at the results from that move to 409.8 Hz, Joe, Rick, and Dripta re-discovered that there's a notch in the DARM loop at 410.3 Hz (see LHO:48530), which is a relatively wide elliptic bandstop (whose boundaries are 409.4 and 411.2 Hz, i.e. 410.3 +/- 0.9 Hz). That means the frequency response change of IFO's response function, C / (1 + G), is changing quite rapidly between the two 410.3 and 409.8 Hz frequencies. *That* means that the traditional, easy, side-by-side PCALXY comparison of lines to arrive at a ratio of amplitudes -- which assumes that the response function ratio isn't changing between frequencies -- becomes harder, and loop model dependent.

As such, yesterday, Joe, Rick, and Dripta got together and posted the proposal outlined last night LHO:69331, to move the lines that inform the PCALXY comparison entirely away from 410.3 Hz, such that the comparison is between
     H1:CAL-PCALX_PCALOSC8_OSC_FREQ    283.91       Already present as a "Systematic Error" line, but now louder, increasing amplitude from 200 to 2000 cts.
     H1:CAL-PCALY_PCALOSC4_OSC_FREQ    284.01       New PCALY line dedicated to this test, set with an amplitude of 1430 cts 

I've implemented their proposal at of 2023-05-05 20:00 UTC.

Knock-on effects:
    - Because there's a new line on PCALY, I wanted to check whether we still have enough OFS range to drive the temporary, ER15 "thermalization" lines, driven by the CAL_AWG_LINES guardian. We do, so we're good there.
    - The new addition of 284.01 Hz PCALY *may* impact (bias) the demodulation (answer) of the 283.91 Hz PCALX systematic error line, given that that line's front-end DEMOD still uses a +/- 0.1 Hz wide SIG band pass, and 0.1 Hz corner frequency low pass, i.e. a 10 second FFT.
    - Because the systematic Error line is much louder, and has a new companion, equally loud "next door," the CW searches may be more likely to complain about sidebands and non-linearities not subtracted out.
    - Because I'm using a new PCALY oscillator, I need to double check that the GDS pipeline still safely subtracts this out in the GDS-CALIB_STRAIN_NOLINES channel.
    - This renders the DEMOD10 PCALX non-functional, since it's stuck demodulating the 409.8 Hz PCALX line that isn't there. Ideally, we'd convert PCALX DEMOD 10 to watching the new 284.01 Hz PCALY line, but that would require a front-end code change. Eventually, once we're done the 24.5 Hz PCALY thermalization line, then we can switch that PCALY DEMOD 4 over to using that. 

Things that need to change in order to accommodate this move:
    (1) Accepted new oscillator settings in h1calex and h1caley SDF systems.
    (2) Modified the pydarm_H1.ini parameter file which now is up to version marked by git hash 156230c7. Parameters cal_line_cmp_pcalx_frequency and cal_line_cmp_pcaly_frequency have changed.
    (3) Pushed new DARM_ERR / PCAL and DELTAL / PCAL EPICs records at these line frequencies with the updated parameter file, using the command
        $ pydarm export --push --epics-only --model /ligo/groups/cal/H1/ifo/pydarm_H1.ini
    (4) Accepted them in h1calcs SDF.

Rick said he's going to take care of modifying the DEMOD SIG and low pass filters for the X Y comparisons as he needs.

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
284.01      PCALY                  PCALXY comparison            H1:CAL-PCALY_PCALOSC4_OSC_FREQ        TURNED ON THIS ALOG
 ----       PCALX                  PCALXY comparison            H1:CAL-PCALX_PCALOSC2_OSC_FREQ        TURNED OFF 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])

(Corey, Jeff, Louis)

Ran another suite of calibration measurements (referencing Camilla's alog 69333).  Measurement ended at 1h54min due to a lockloss (most likely seismic, specifically 5.9 EQ from Japan).

• Took us out of OBSERVING & took ISC_LOCK to NLN_CAL_MEAS
• Opened terminal and entered/ran:  "pydarm measure --run-headless" at 1626utc.
• LOCKLOSS at 1820utc with lots of seismic motion (possibly 5.9 Japan quake 20min before---The Lockloss "occurred during last broadband measurement, but they got all the measurements that really matter." (JeffK)
• I CTRL-C-ed out of measurement terminal and Louis walked me through killing the Test Point.

Attached is a screenshot of the sitemap > CAL CS > Calibration Monitor screen shortly after starting the measurement.

• Measurement at:  /ligo/groups/cal/H1/measurements/PCALY2DARM_BB/PCALY2DARM_BB_20230505T162712Z.xml

'pydarm report' command gave attached report: 

• /ligo/groups/cal/H1/reports/20230505T174611Z/H1_calibration_report_20230505T174611Z.pdf

As a target of opportunity during lockloss downtime, I ran the End Y Hepta roughing pump which is located in the mechanical room from ~11:40am to ~11:50am local time.  There is an outstanding question of how much of a noise issue it is to run this pump during non-Tuesday-maintenance periods during the Engineering Run.  I have tagged PEM so they can have a look at this.

The IMC_LOCK node has been notifying of the IMC WFS not being centered for some number of days. While we were waiting for a small earthquake to roll through, I centered the WFS with a reminder from Sheila's alog54340. Steps were:

1. Offload the MCWFS via IMC_LOCK
2. Bring IMC_LOCK to OFFLINE
3. Use the handy ndscope template on the IMC screen and the picos to center the signal on the WFS
4. Accept any SDF diffs, these were in IMCASC from the MCWFS offloading (attach 1)

A screenshot of the final ndscope showing the movement is attach 2.

We have been changing the digital SRCL offset to undetune ("zerotune"- Peter F.) the SRC. However, we are wary of saturating POP RF45, and also leaving enough ADC range to handle any glitches. We have been running with 21 dB of whitening gain on POP45. I just did a quick measurement while we are down to determine if we can change the whitening gain. We are shot noise limited on this photodiode, with about 1e-10 W/rtHz of shot noise. The attached screenshot shows three measurements: in lock with 35 mW incident, a dark measurement (IMC offline) with the whitening on, and a dark measurement with the whitening off. Jenne and I determined we can reduce the whitening gain by 6 dB. I made this plot showing the comparison of the three measurements.

I updated the whitening gain and the anti-whitening gain filter to be 15 dB and -15 dB respectively. These changes were SDFed by Jenne.

This will hopefully allow to increase the magnitude of the SRCL offset further.

J. Kissel

We've been confused when reading off calibration line frequency values from the PCAL oscillator MEDM screen more times than I'd like to admit, so I've edited the screen such that all displays of oscillator frequencies have a precision of 4 digits beyond the decimal place. Compare first row of values in the attached before vs. after.

Screen update has been committed to
    /opt/rtcds/userapps/release/cal/common/medm/
        PCAL_END_EXC.adl

for LLO to import should they so chose.

Fri May 05 10:05:44 2023 INFO: Fill completed in 5min 43secs

Travis confirmed a good fill via camera.

To synchronize the CDS Overview and GDS_TP MEDM colours for O4, I've modified calm_fpu.py to change the colour of some STATE_WORD blocks to RED. The colour changes implemented by this code are:

These changes will be made permanent in future RCG releases, but obviously we would not do an RCG upgrade for these cosmetic changes.

L. Dartez, J. Kissel, J. Rollins

In order to
    - Improve the answer for the optical gain and cavity pole with the 2023-05-04 (2023-04-20 was the last update had a different 2023-05-03 SRCL offset LHO:69289 and 2023-04-26 TCS settings LHO:69032)
    - Make sure GDS has absorbed the PCALX calibration line change from 410.2 Hz to 409.8 Hz (LHO:69303)
    - Exercise the more automated updates to "the calibration" using the new command line infrastructure
    - Populate the "compensated for time dependence" CFTD path with the correct optical gain (hasn't been updated in forever)
    - synchronize the push of CAL-CS Filters, EPICs records and GDS pipeline's FIR filters with the latest parameter file
we've pushed a new calibration to "the calibration," updating
    :: H1:CAL-DELTAL_EXTERNAL_DQ
    :: H1:GDS-CALIB_STRAIN
    :: H1:GDS-CALIB_STRAIN_NOLINES

The preliminary results, by eye, indicate that everything looks great.

Notes are attached. More details to come.

TITLE: 05/05 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: 15mph Gusts, 12mph 5min avg
    Primary useism: 0.04 μm/s
    Secondary useism: 0.13 μm/s
QUICK SUMMARY:

H1's been locked just over 2hrs (after being down ~100min to relock on its own).  Range is hovering just below 135Mpc.

I have updated the IMC_LOCK guardian to open the ISS second loop if the diffracted power changes by more than 30% when first closed, then close it again. The check lives in the CLOSE_ISS state, where the necessary things are done to close the second loop. When the second loop closes, the guardian now waits for 30 seconds to see if the ISS diffracted power changes by more than 30% (high or low), and if it does, request OPEN_ISS to open it again. The node will stall briefly, but then it will move to close the second loop again by going through the LOCKED and CLOSE_ISS states. This update should fix our recurring issue where the input power differs lock to lock due to the second loop engaging its DC coupling at an irregular place and changing our input power, sometimes by up to 1.5W.

I encountered an issue when testing this change where if the node had a notification, in this case the IMC WFS needed centering, the unstall_nodes decorator used by ISC_LOCK to revive its subordinates wouldn't work. This meant that IMC_LOCK would see the diffracted power had changed too much, correctly move to OPEN_ISS, then get stuck. To remedy this, TJ and I decided the best course of action was to move this notification into DIAG_MAIN. I then raised the threshold for the IMC WFS checker in IMC_LOCK to 0.7, up from 0.5, so that IMC_LOCK would only show a notification if the WFS are very off-centered.

All of these changes have been appropriately updated in svn.

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.