FAMIS 26440

BRS Y looks good.

BRSX has been damping for the last few weeks after the remote mass adjuster upgrade, but it is still within range.

FAMIS 26463

Looks stable over the last month. The drop out is during the CDS switch upgrade and subsequent tripping of the pump station.

TITLE: 02/26 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 30mph Gusts, 24mph 5min avg
    Primary useism: 0.05 μm/s
    Secondary useism: 0.37 μm/s
QUICK SUMMARY:

17:27 4.9 Mag Earthquake from Idaho, trips ISI's but no suspensions.

18:00 UTC PSL gets green light from CDS but the PSL folks say things are still not right.
18:30 UTC the PMC started to work correctly again.

Seismic to calm 19:50 UTC

Monthly test of Hanford system 12:30 - 1 pm

Transition to hazard 12:30 Local time
Out of medium garb

The Combiner was ran down X arm.

Oplev work is still in progress.
HAM6 Camera work is still in progress.
Vacuum System has passed some leak tests and is still pumping down.
 

FAMIS26284

EX Fan1 noise is starting to increase in the last 2 or 3 days. FMCS team will be contacted.

All others look as stable as before.

FAMIS 26232

PSL team has been keeping an eye on the listed issues since the PSL had an ADC issue over the weekend (alog75963).

Laser Status:
    NPRO output power is 1.823W (nominal ~2W)
    AMP1 output power is 67.64W (nominal ~70W)
    AMP2 output power is 136.9W (nominal 135-140W)
    NPRO watchdog is GREEN
    AMP1 watchdog is GREEN
    AMP2 watchdog is GREEN

PMC:
    It has been locked 0 days, 3 hr 45 minutes
    Reflected power = 19.7W
    Transmitted power = 106.3W
    PowerSum = 126.0W

FSS:
    It has been locked for 0 days 0 hr and 56 min
    TPD[V] = 0.6414V

ISS:
    The diffracted power is around 2.8%
    Last saturation event was 0 days 0 hours and 0 minutes ago

Possible Issues:
        PMC reflected power is high
        FSS TPD is low

The temperature in Zone 4 of the LVEA fell drastically this morning at 10:57 am. The cause was due to a clean room being turned off, confirmed by Gerardo, and the space temperature had previously been lowered to address the added heat from the clean room. Once the clean room was shut off, the zone was able to reach its set point of 65. I raised the set point back to 67.5, which was the set point prior to the vent. The zone cooling signal is slowly decreasing and it will begin to heat once the program boosts the heating signal. 

FAMIS 20017

The PMC was unlocked for the past day due to a lost ADC card (alog75956), so this is reflected in many places in this week's trends.

FRS30546

Richard, Fil, Jonathan, Erik, Tony, Dave:

This morning we power cycled the h1psl0 front-end computer and IO Chassis. At this time the 4th ADC returned to the bus, but we decided it was too risky to go into O4b with a suspect ADC in the PSL. Fil replaced the ADC with a brand new spare.

At this point the Contec6464 card became partially unseated which caused PCIe bus errors, but after this was reseated we have a fully operation h1psl0 with a new 4th ADC card.

The old card was given to Erik for testing on the DTS.

Mon Feb 26 10:11:46 2024 INFO: Fill completed in 11min 42secs

Gerardo confirmed a good fill curbside.

TITLE: 02/26 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    SEI_ENV state: CALM
    Wind: 10mph Gusts, 8mph 5min avg
    Primary useism: 0.03 μm/s
    Secondary useism: 0.33 μm/s
QUICK SUMMARY:
A number of alarms are alarming:
Type Error While running Test : PSL_NOISE_EATER this is due to a PSL DAC issue.
Dave jumped onto team speak and let me know that we will likely have to swap hardware when Fil arrives.
Vacuum pressure alarm for End X was yellow. H0:VAC-EX_X5_PT526_MOD1_PRESS_TORR.






 

Sun Feb 25 10:09:42 2024 INFO: Fill completed in 9min 38secs

At 04:26:10 Sun 25 Feb 2024 PST all the models on h1psl0 crashed.

lspci shows we have lost an ADC card, only 3 are visible on the bus.

dmesg output:

[Wed Feb 21 12:08:41 2024] nfs: server 10.101.0.17 OK
[Sun Feb 25 04:27:11 2024] rts_cpu_isolator: LIGO code is done, calling regular shutdown code
[Sun Feb 25 04:27:11 2024] h1ioppsl0: ERROR - An ADC timeout error has been detected, waiting for an exit signal.
[Sun Feb 25 04:27:11 2024] h1psldbb: ERROR - An ADC timeout error has been detected, waiting for an exit signal.
[Sun Feb 25 04:27:11 2024] h1pslfss: ERROR - An ADC timeout error has been detected, waiting for an exit signal.
[Sun Feb 25 04:27:11 2024] h1pslpmc: ERROR - An ADC timeout error has been detected, waiting for an exit signal.
[Sun Feb 25 04:27:11 2024] h1psliss: ERROR - An ADC timeout error has been detected, waiting for an exit signal.
(diskless)root@h1psl0:/home/controls# 
 

I. Abouelfettouh, J. Kissel, O. Patane, B. Weaver

Executive Summary: The first article BBSS transfer functions look great. Though there is some confusion about the M1 P 2 P modeled transfer functions drastically disagreeing with the measured TFs, there is a consistent story between 
    - the adjustments to the mechanics that were made during construction and 
    - deviations from the "production" model parameter set that could re-create those construction adjustments. 
Further discussion will be had with the assembly / design team as to the future course of action.
Kissel suggests that -- even as the first article stands now -- the resulting measured transfer functions with the mechanical adjustments would/should happily meet A+ O5 requirements.

%%%%%%%%%%% Begin kLOG (You missed these...) %%%%%%%%%%%%%%

I got a debrief yesterday from Betsy, Oli, and Ibrahim of the comparison between 
    - measured transfer function results from the first article construction and
    - what had been deemed the production model parameter set for the BBSS,
i.e. what's discussed in LHO:75787.

The existing "production" model parameter set starts from Mark's update to the BBSS parameter set post-final-design after adjusting for the production wire thicknesses (see TripleLite2_mark.barton_20211212bbss_production_triplep.m, changed at rev 11625, circa Sep 2023). Oli successfully copied over to the usual matlab formating to create bbssopt.m (created at rev 11734, circa Jan 2024).

At the start of the debrief, there were (only!!) 3 outstanding issues / questions they had:
    (1) The overall magnitude scale for all DOFS for all measured transfer functions was a consistent factor of ~3.15x more than the model estimates,
    (2) After browsing through the EULER-basis drive to OSEM-basis response plots, and some of the off-diagonal EULER-basis showed little-to-no coherence, and
    (3) The measured M1 Pitch to Pitch transfer function's frequency response was significantly different than the model.

For (1), this is typically a sign of a mis-calibration of the data. We reviewed the calibration of the measured data from the processing script, plotBBSS_dtttfs_M1.m, created by Oli and Ibrahim in Nov 2023. The DTT templates that measure the transfer function use the pre-calibrated output of the sensors for response channels i.e. the channels come in units of microns and microradians, so they only need a factor of 1e-6 [meters / micrometers]. The only substantial thing that needs calibrated into physical units during post-processing is the excitation. The review of the calibration of the exciation revealed nothing suspicious in the script based on our current expected knowledge of chain
    - the test stand electronics (an 18-bit DAC = 20 / 2^18 [V/ct]), 
    - BBSS coil driver (a TTOP coil driver, coupled with a BOSEM coil = 11.9 [mA/V]), 
    - 10x10 magnet strength (1.694 [N/A]).
    - (lever arms and numbers of actuators are pre-calibrated out via the EUL2OSEM matrix, generated by make_susbbss_projections..m, and installed in EPICs)
The above factors result in an overall calibration of 1 / 1.5405 [(m/N) / (um/DAC ct) or (rad/N.m) / [urad/DAC ct]] that's displayed in the legend of each of the plots from LHO:75787.

In the end, we were more interested in understanding (2) and (3) rather than getting to the bottom of the calibration. Further, the test stand is some old, pre-aLIGO concoction whose records and modifications are unclear. So we figure we just move on, accepting that we need to fudge the data by the extra factor of 3.15x. We'll get serious about figuring it out if there's still such a discrepancy after moving the BBSS over to the production H1 system.

For (2), all concerns can we waived off with expectations. 
    (a) The first plot of concern was the P to F1F2F3 plot (page 17 of 2024-01-05_1000_X1SUSBS_M1_ALL_TFs.pdf), in that the magnitude of the F2 and F3 TFs were low and/or noisy. This is expected because F2 and F3 OSEMs are along the (center of mass / axis of pitch rotation) of the BBSS's top mass. So they see no pitch by construction (for better or worse).
    (b) The second collection of plots of concern were the off-diagonal DOFs, 
        (i) showing noise and/or 
        (ii) the opposite -- showing well-resolved cross-coupling in DOFs that we *don't* want cross-coupled. 
        We shouldn't be mad about (i) -- e.g. page 7 showing incoherence between L response to V drive and V response to L drive. What power is resolved in those transfer functions -- typically on/around resonances -- is because the TFs were taken undamped an in air. So there's just a ton of movement that an FFT might / cross-correlation might *think* is coherent with the drive, but it's really not.
        We looked closer at any of the off-diagonal TFs that *were* resolved, (ii) -- e.g. page 9 showing well-resolved cross-coupling between R response to V drive and V response to R drive. In each of these TFs, we found that the magnitude of the cross-coupling, off-diagonal TF was less, if-not-MUCH less that the on-diagonal TF, which is good. Where it was close, it sort-of "is what it is." Little attention has been typically paid to mitigating the off-diagonal transfer functions during the design phase of LIGO suspensions to-date. Further, they often are a result of the unique construction of each individual instantiation of the suspension type. There's no much we can do about it post construction, and what we *do* do if it proves problematic to the detector, is dance around the problem with fancy controls techniques if needed.

For (3), we arrive at the meat of this aLOG ::  The *model* of the M1 Pitch to Pitch transfer function looked very weird to me. Betsy mentions the during the construction of the first article they 
    (a) found a discrepancy between the fastener model vs. measured mass budget that resulted in an unclear relationship between the center of mass of each stage and their suspension points (typically called the "d" parameters)
    (b) acknowledged there would be uncertainty in the location of the suspension point for the bottom mass / dummy optic given the wire-loop + optic prism system since the final distances between masses have not been measured.

This, coupled with the fact that no *other* DOFs disagreed with the model besides P to P, led me to suspect the model parameters that only impact the pitch dynamics may be incorrect: 
    (i) each stages' separation between suspension point and center of mass, the "d" parameters, and 
    (ii) the pitch moments of inertia.

For a reminder of the physical meaning of all of the triple suspension parameters, see T040072.

As such, using the bbssopt.m "production" or "Final Design" (FD) parameter set as starting point, we tweaked these parameters by 10%-ish or factors of 2 to gather intuition of of how it would impact the response of the P to P transfer function. As a result, we have come to the conclusion that, in order to explain the data, we need to
    - increase "d1" by + 5 [mm]. This is the separation between the top (M1) mass center of mass and it's M1 to to M2 blade tip heights. In the absolute sense, this is increasing the "physical" d1 from -0.5 [mm] to +4.5 [mm], and
    - increase "d4" by 1.5 [mm]. This is the separation between the bottom (M3) mass / dummy optic center of mass and the wire/prism break-off point. In the absolute sense, this is increasing the "physical" d4 from +2.6 [mm] to +4.1 [mm].

Check out the attached plots which demonstrate this.
Citing discussion of overall scale (1) from above, all *measured* transfer functions have been scaled to the model by a factor of (1 / 3.15). This just makes comparing model to measured frequency response a lot more clear.

First attachment :: comparison between the final design model parameters and a variety of reasonable deviations of d1 between *decreased* by 2.5 [mm] and *increased by 5 [mm]. You'll notice that once d1 surpasses +1.0 [mm], the transfer function starts to look more like a standard triple suspension's transfer funtion. a d1 of FD + 5.0 [mm] lines up well with the upper two resonances of the measured data, but reduces the frequency of the lowest two L and P modes to below the data.

Second attachment :: comparison between the final design model parameters and a variety of reasonable deviations of d4. You'll notice that d4 really only have an impact on the lowest two L and P modes.

Third attachment :: comparison between the final design model parameters and a variety of reasonable deviations of the top (M1) mass' moment of inertia, the I1y parameter. 

Fourth attachment :: comparison between the final design model parameters and a variety of reasonable deviations of the middle (M2) mass' moment of inertia, the I2y parameter. 

Fifth attachment :: comparison between the final design model parameters and a variety of reasonable deviations of the bottom (M3) mass' moment of inertia, the I3y parameter. 

None of the modeled changes to the moment of inertia -- shown in the third, fourth, and fifth attachments -- show promise in reproducing the measured results.

Sixth and Final attachment :: comparison between the final design model parameters and one with only d1 increased by +5 [mm], and d4 increased by +1.5 [mm].

The modified model in this last attachment fits the data the best, so we conclude that the issues with mechanical construction (3a) and (3b) are consistent with the measured data :: the reconfigured mass budget needed from fastener issues resulted in a deviation from design value for d1, and the imprecision of the mass-to-mass distances and wire-loop / prism system resulted in a roughly ~2 [mm] slop for this assembly.

%%%%%%%%%%% End kLOG (You missed these...) %%%%%%%%%%%%%%

Big Picture Systems Level Commentary by Jeff :: If these measured transfer functions end up being the reality of the final frequency response of the BBSS -- this will be totally fine. The pitch isolation one gets above the resonances (defined mostly by the moment of inertia) is the same, the lowest L and P modes are sufficiently low, and the details of where the rest of the resonances land are totally inconsequential / amenable to a damping and global control design.

Sat Feb 24 10:07:21 2024 INFO: Fill completed in 7min 17secs

Dana, Louis

I tried generating the calibration report for report ID 20231011T202627Z but was unable to do so. The following error was returned: 

ValueError: ('There are no common frequency points for the ', 'two transfer functions. Maybe check coherence', ' thresholds.')

For the full error message, see attached txt file.

Kevin, Sheila, Evan, Vicky

Summary: SQZ-OMC mode scans with hot OM2, and PSAMS 120/120 vs. 200/200. From this data, we should get single-bounce SQZ-OMC mode-matching with hot OM2, check SQZ readout losses (AS port throughput), and measure OMC losses via cavity visibility when locked/unlocked to the squeezer beam. With hot OM2, in sqz single bounce, SQZ-OMC mode-matching looks a bit better with PSAMS 120/120 than 200/200.

We'll ask Jennie W. to help us fit these SQZ-OMC mode scans. She can fit the double-peak in the 2xHOM, to give an accurate measure of SQZ-OMC mode-matching with hot OM2 and these two PSAMS settings. Here is just naively calculating mismatch from the relative power in TEM20 (TEM20/(TEM00 + TEM10/01 + TEM20)), and then calculating the total power not in TEM00 (ie 1-TEM00/(TEM00 + TEM10/01 + TEM20)), to get the following estimates on SQZ-OMC mode matching:

PSAMS 120/120, scan: 10/24/23 19:46:53 UTC + 200 seconds.
   --> mismatch ~ TEM20/peak_sums ~ 2%.      Total incl. mismatch + misalignment: 1-tem00/peak_sums ~ 8%.
PSAMS 200/200, scan: 10/24/23 19:04:57 UTC + 200 seconds.
   --> mismatch ~ TEM20/peak_sums ~ 5%.      Total incl. mismatch + misalignment: 1-tem00/peak_sums ~ 12%.

We will follow-up with analysis on OMC loss measurements based on cavity visibility, more accurate SQZ-OMC mode mismatches from these scans, and checking single-bounce SQZ powers through the AS port.

---------------------------------------------------------------------------

Notes:

• To begin SQZ-OMC mode scan, if SQZ-IFO is aligned -- with SRM aligned, SR2 + SR3 misaligned, Open sqz beam diverter, open fast shutter.
  • We started aligning with the PSL beam before we realized we forgot to open the fast shutter. For reference with this working, 10W PSL gave about  ASC_AS_{B,C}_DC_NSUM_OUT16 ~ 2000, ASC-AS_C_NSUM_OUT16~0.023, ASC-OMC_{A,B}_NSUM_OUT_DQ~0.023.  
  • With 75mW seed power into SQZT0 seed fiber, and opo at LOCKED_SEED_DITHER:
    • At the end, we measured the opo ir transmitted powers on sqzt7: OPO_IR_PD_LF_OUTPUT = 0.867mW, and OPO_IR_PD_DC_POWERMON = 0.856mW. This PD calibration was checked recently LHO:72761, Sept 2023.
    • 51 counts on ASC-AS_{A/B}_DC_NSUM_OUT16, 520e-6 counts on ASC-AS_C_NSUM_OUT16.
  • Then engaging DC3/4 centering loops worked. 
  • Then OMC QPD ASC set master gain to 0.02 (one click up), this aligned OM3 + OMC SUS. 
• Lock OMC on SQZ seed beam as carrier. Sheila manually walked through relevant OMC_LOCK guardian steps, including manual scan of OMC PZT2 volts to find sqz tem00 carrier.
  • Set trigger to 0 or 0.1 for OMC to lock on SQZ seed beam as the carrier 
• Turn on OMC QPD ASC servo to align OM3+OMC SUS to sqz beam. Master gain = 0.02 (one click up). With OMC QPD ASC, this brought DC sum = 0.4 now, which from DTT was the TEM00 peak height.
  • OMC scan here before walking OMC QPD alignment, PSAMS 200/200. DTT Refs 24 (dcpd sum), 25 (omc pzt). 
• Manually optimize OM3/OMC alignment with OMC locked on SQZ beam. This was after using & converging OMC QPD servos, then turning them off. Mostly walking yaw between OM3/OMC, then slightly in pitch. This manual walking improved OMC DCPD SUM transmission from 0.405 to 0.411 (~1.5% improvement).
• We can compare OMC visibility with OMC locked/unlocked from the SQZ beam. Follow up: calculate OMC losses from OMC-SQZ locked/unlocked visibility.
  • Locked GPS times, PSAMS 200/200: 1382207658 - 1382208152
  • Unlocked OMC:  Turned off integrator, boost, trigger, then moved PZT offset to off-resonance. 
  • Unlocked GPS times: 1382208285 - 1382208585
  • Dark noise: Turned off DC centering, fast shutter, sqz beam diverter.
  • Dark GPS times: 1382208720 - 1382208813
  • Then re-opened sqz beam diverter, opened fast shutter, DC centering loops DC3 + DC4 engaged, OMC QPD ASC master gain set to 0.02, converge OMC QPD ASC then freeze it, then scan OMC-PZT2_OFFSET (green slider). Use PZT2 offset scan to manually find SQZ TEM00 carrier. Turn ON OMC-LSC servo input, integrator, boost. Manually re-align OM3 + OMC SUS to optimize OMC-DCPD_SUM_OUT transmission. Again it was mostly yaw on OM3+OMC, then slightly pitch; manual walking improved alignment slightly (few %) again.
• PSAMS 200/200 data, with re-optimized alignment:
  • Locked GPS times, PSAMS 200/200: 1382209341 - 1382209482
  • OMC Scan, PSAMS 200/200. DTT Refs 26 (dcpd sum), 27 (omc pzt). Gpstime: 10/24/23 19:04:57 UTC, 100 second ramp.
  • Unlocked GPS times: 1382210147 - 1382210207
• Changed ZM4/5 PSAMS to 120/120, left DC3/4 centering ON. Re-lock OMC on seed beam (without touching OMC QPD ASC since we previously aligned/optimized it). With OMC-SQZ locked again and same OM3+OMC alignments as before, alignment with psams120/120 is not good. Some alignment confusion with OMC-LSC servo bank saturating. We turned back on OMC QPD ASC master gain 0.02 since we were kinda far off in the alignment. Here with hot OM2, the OMC transmission looks higher with PSAMS 120/120 than with PSAMS 200/200.
• PSAMS 120/120 data, with re-optimized alignment:
  • Locked GPS times, PSAMS 120/120: 1382211311 - 1382211449
  • Unlocked GPS times: 1382211637 - 1382211755
  • OMC Scan, PSAMS 120/120. DTT Refs 28 (dcpd sum), 29 (omc pzt). Gpstime: 10/24/23 19:46:53 UTC, 100 second ramp.

---------------------------------------------------------------------------

Some relevant alogs, as we try to piece together the SQZ-IFO, IFO-OMC, and SQZ-OMC mode matchings:

• Cold OM2, single bounce SQZ-OMC mode scans, alignment less controlled than this time: Jan 2023, LHO:66946.
  • Cold OM2, single bounce, PSAMS 200/200 ~ better SQZ-OMC mode-matching.
• SQZ-IFO full-lock frequency-dependent mode matching: LHO:73400 first pass, then LHO:73621 repeat with ASC frozen.
  • Hot OM2, full lock, PSAMS 200/200 ~ better SQZ-IFO(-OMC?) mode-matching. DARM SQZ noticeably flatter in this configuration.
  • 200/200 better also suggested by ADF transmission + more anti-squeezing.
• Hot OM2, single bounce SQZ-OMC mode scans (this alog):
  • Hot OM2, single bounce, PSAMS 120/120 ~ better SQZ-OMC mode-matching.