Closes FAMIS 26040. Last checked in alog 83968.
HAM4, HAM7, HAM8, EX ST1 all have elevated peaks, mostly around 1Hz line. This is expected due to high maintenance and vent activity.
Closes FAMIS 26375. Last checked in alog 84000,
Everything is under threshold. There are different fans on than last week so difficult to compare. MR FAN3 in CS has a slightly higher noise character in last 3 days
While prepping the HAM1 ISI for testing last night, I noticed that one of the HAM2 HEPI L4Cs seemed non-responsive. It seems this has been the case for quite some time, 206 days according to the attached ndscope. Something happened on Oct 1st last year that cause this L4C to suddenly have only ~1/50th the signal the H2 L4C on the HEPI to sees. I have poked at it a bit, checked cabling on the pier and gently hit the foot to see if I could revive the sensor. I have a couple other tests I want to do before deciding to remove the actuator to replace the sensor, not exactly eager to have to do that.
Dry air skid checks, water pump, kobelco, drying towers all nominal. Dew point measured at HAM1, reading -43.8°C
. Main turbo pumps, XBM, YBM and OMT, all nominal, and temperature is good and stable. HAM6 turbo pump and cart are nominal.
WP12488 HAM8 ISI binary readback broken following site outage FRS33798
Fil, Erik, Jim, Dave:
Yesterday we power cycled the binary input/output and interface chassis, which did not fix the issue. Today we stopped all the models on h1cdsh8, powered down the computer, then power cycled the IO Chassis.
This also did not fix the problem. Investigation continues.
Fri25Apr2025
LOC TIME HOSTNAME MODEL/REBOOT
11:15:32 h1cdsh8 ***REBOOT***
11:17:25 h1cdsh8 h1iopcdsh8
11:17:38 h1cdsh8 h1isiham8
11:17:51 h1cdsh8 h1susfc2
11:18:04 h1cdsh8 h1sqzfces
11:18:17 h1cdsh8 h1susauxh8
11:18:30 h1cdsh8 h1pemh8
Some changes to the RM1/RM2/PM1:
All other things equal the local damping loops should have the correct sign now. Thic change will also require a sign change in the ASC centering servos.
"Yes, and..." - It makes sense to zero the ALIGNMENT offsets for RM1, RM2, and PM1. They're physically aligning the optics in chamber this week, so we don't want to get confused by having digital offsets driven out to the coils. - Daniel says "Changed the signs of the coil outputs for RM1 and RM2. This should account for the sign change of the OSEM voltages." Here, "the change in sign of the OSEM voltages" means the fixing of the "has been like that forever as far as we can tell" issue that the RM1 and RM2 OSEM PD sensor readback's ADC voltage had been negative when under light. The fix was in the in-air DB25 feedthru to satamp cable; see LHO:84027 and subsequent comment about the differences in satellite amplifiers. He acknowledges that this fix will disrupt the overall sign of the damping loops, so he just *picked* a place to flip the sign. He chose the COILOUTF banks, but . we use these banks to explicitly compensate for the magnet polarity, and . RM1 and RM2 have already confirmed to be different in this regard in Mar 2018; see LHO:40853 -- and in that aLOG we concluded it was RM2 that was abnormal because RM2 required a different damping loop gain than RM1, OM1, OM2, and OM3 when all *settings* were otherwise the same. . HOWEVER given that the OSEM sensor readback itself had a negative in it, I'm no longer convinced it's RM2 that's the problem. But at least we know they're different. . I tried to have Betsy/Rahul go in chamber to confirm magnet polarity but these HTTS magnets are particularly hard to get at / measure, given that they're buried within the flag and the PEEK flag can no longer be unscrewed from the aluminum optic holder; see LHO:84178 So, since we're left stuck not understanding the coil actuator magnet polarity, I *don't* want to fix the *sensor* sign here. We've reverted the above change of COILOUTF signs. They're now restored to $ caget H1:SUS-RM1_M1_COILOUTF_UL_GAIN H1:SUS-RM1_M1_COILOUTF_LL_GAIN H1:SUS-RM1_M1_COILOUTF_UR_GAIN H1:SUS-RM1_M1_COILOUTF_LR_GAIN H1:SUS-RM1_M1_COILOUTF_UL_GAIN 1 H1:SUS-RM1_M1_COILOUTF_LL_GAIN -1 H1:SUS-RM1_M1_COILOUTF_UR_GAIN -1 H1:SUS-RM1_M1_COILOUTF_LR_GAIN 1 $ caget H1:SUS-RM2_M1_COILOUTF_UL_GAIN H1:SUS-RM2_M1_COILOUTF_LL_GAIN H1:SUS-RM2_M1_COILOUTF_UR_GAIN H1:SUS-RM2_M1_COILOUTF_LR_GAIN H1:SUS-RM2_M1_COILOUTF_UL_GAIN -1 H1:SUS-RM2_M1_COILOUTF_LL_GAIN 1 H1:SUS-RM2_M1_COILOUTF_UR_GAIN 1 H1:SUS-RM2_M1_COILOUTF_LR_GAIN -1 - He's confirming our work on PM1 from LHO:83293 - 2025-04-29, Daniel has made the model changes in h1sushtts, but they've not yet been installed as this is a trivial top-level model change that has been there forever, and is blocked from reaching the DAC by just turning of the SUS-RM*_ISCINF_L bank inputs. - We'll re-address the damping loop signs once the dust settles with chamber work.
FAMIS27814
Our cadence is a bit off from biweekly, but no matter since no water was added and the chillers look good (updated the T2200289 sheet). There is a small amount of blueish gunk starting to form in the wire mesh diffuser in the TCSX chiller. I didn't see any of these in our parts bin so I'll put a few on order.
Fri Apr 25 10:08:57 2025 INFO: Fill completed in 8min 53secs
Gerardo confirmed a good fill curbside.
FranciscoL, SheilaD, JoeB
In summary:
I regenerated the mcmc fit on report 20250327T160138Z at 5, 10 and 20 Hz, to compare how the mcmc model would change given different frequency ranges for the fit. We see that the residual of the measurement to the model is better as we increase the minimum frequency threshold. We think this is due to external effects, aside SRC, confusing the model.
We want to give more validity to our observations on alog 83592 -- that the sensing model at low frequencies is a good descriptor of the sensing function. On 83592, I claimed that the observed changes in the sensing function come from changes in SRCL detuning. This is backed up by a low residual on the measured/modeled sensing function. In today's alog, we evaluate how well the model describes the sensing function by (1) having a *low* residual and (2) decreasing the optical spring frequency.
The first three figures attached ('sensing_mcmc_compare_*Hz.png') are the sensing function plots generated by pydarm for measurement 20250327T160138Z. This measurement is not a representation of a calibrated interferometer, since we tuned the SRCL detuning (83585).
From the transfer function on the left, the green dots represent the measurement, the orange trace is the mcmc model from the measurement, and the blue trace is the mcmc model from the last validated calibration measurement (20250222T193656Z). The residual from the measurement to both models are plotted on the right, matching the colors of the respective models. We are interested in the change of the orange trace when we modify the frequency range of the fit.
Each figure has a pair of vertical lines denoting the limits on the frequency range used for the fit. I regenerated the measurement report for 05, 10, and 20 Hz for the minimum frequency. The maximum frequency at 1200 Hz was not changed.
For the residual plots, we see that the magnitude is largest when fitting to 5 Hz, and that the change between the 10 and the 20 Hz fits is negligible. For illustration purposes, I plotted the different sensing models, along with the measurement, together in the last figure (20250327T160205Z_compare_models). The phase plot is not the same as the plots given by pydarm due to missing factors. We see that the three models match above 30 Hz in magnitude.
For the optical spring frequency, we see a decrease from 2.19 Hz to 0.43 Hz when fitting to 10 Hz, and 20 Hz, respectively. This decrease on the SRC spring suggests that the model does not fit the sensing function well, below 20 Hz.
So, regenerating the sensing model shows that the model is good when we see anything above 20 Hz. But we see from the measurement that the SRCL detuning does change the sensing function at low frequencies. The model, however, cannot fit the data from the measurements at these frequencies. We have seen before (80267) that angle to length cross coupling influences the sensing function in the low frequencies. A scenario of cross coupling affecting the sensing function could explain why the model cannot fit the measurement.
Repeating the analysis on cross-coupling, as done in 80267, could improve the sensing function.
TIL; pydarm edition:
The approach that enabled me to regenerate pydarm reports, albeit messy, was to
Modify the pydarm_cmd_H1.yaml
that is in the report to be regenerated, in this case 20250327T160138Z. In particular, the mcmc_fmin
value.
Once the YAML file is configured, run
This command will re-run the calibration report, and, by using the configuration that lives in that directory, make a new model to the sensing function measurement.
TITLE: 04/25 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: MAINTENANCE
Wind: 1mph Gusts, 0mph 3min avg
Primary useism: 0.06 μm/s
Secondary useism: 0.09 μm/s
QUICK SUMMARY:
IFO is in PLANNED ENGINEERING for VENT
Some planned tasks for today:
Work safe!
Jordan, Janos, 04-24-2025, ~15:00 The wire gaskets for VBO-C and VBO-D have been leaking continuously for a very long time. Lots of vendors have been contacted, and after a lot of unsuccessful tests, it seems that we finally found the good one manufactured by Torr Scientific (UK). This gasket is extremely annealed, butter-soft, needs super careful handling, but even after some suboptimal installation steps (mea culpa), it finally sealed a new chamber successfully. We tested it right after receiving (had a thriller with customs) with a new C+B chamber, pumped it down and tested on the same day. After the test, we let the pump running during the weekend just to see the ultimate pressure it can reach. They are still very pricey though, 193 GBP (= 257 USD)/pc., even in the case of purchasing 100 pcs., it's 147 GBP (= 196 USD)/pc. So, certainly not an optimal, long-term solution, but a good bridge between having nothing and manufacturing our own.
Good news! Let's take some detailed measurements (as possible), also how close they fit over the flange lip, etc. Will help us when we start fabrication in house.
Oli, Matt, Camilla
Late entry, Jim and I worked the last few half days to lace up all of the cabling for SUS, SEI, and IO/ISC in prep for the main reinstall of table components. Fil, some Richard, and I did preliminary ground loop checks on all SUS and IO/ISC cables so we have a handle on the situation before complicating with components. I routed cables on the table top in an attempt to be near where things plug in but also not in the way of landing objects. Further dressing and coiling will be needed after troubleshooting plugins with components as we go. Pics of the pre round of cabling.
Oli, Camilla
This morning we swapped the direction of HW1 so that it is facing the same as before. We also placed L2, M15, LSC POP A and ASC POP X although the diodes are not cabled up yet. They can be next week as Daniel confirmed chassis are powered off.
ASC POP X is new, the box is marked D1102004-v6 S/N 016 S1300637, ICS link. Have added this to the D1000313 BOM googledoc and HAM1 ICS assembly.
Tagging with EPO to document the process.
TITLE: 04/24 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:
IFO is in PLANNED ENGINEERING for VENT
Productive day where most of the work was spent on HAM1 cabling, followed by RM1 install.
Of note:
LOG:
Start Time | System | Name | Location | Lazer_Haz | Task | Time End |
---|---|---|---|---|---|---|
14:39 | FAC | Kim | LVEA | N | Tech clean | 15:52 |
14:39 | FAC | Nellie | LVEA | N | Tech clean | 15:52 |
15:45 | VAC | Jordan | LVEA | N | Purge air checks | 16:03 |
15:45 | SUS | Betsy | LVEA | N | Cabling HAM1 | 18:59 |
15:52 | FAC | Nellie | H2 | N | Tech clean | 16:07 |
16:07 | SUS | Randy | YARM | N | QUAD Moving | 23:24 |
16:33 | SUS | Richard | LVEA | N | Cabling/H.O.R.S.E. | 17:03 |
16:50 | SUS | Mitchell | EX, EY | n | FAMIS tasks | 22:50 |
16:56 | SUS | Travis | LVEA | N | Cabling | 17:06 |
17:07 | FAC | Kim, Nellie | MY, MX | N | Tech clean | 18:51 |
17:53 | VAC | Jordan | MX, MY | N | Emergency Pump Survey | 18:38 |
17:53 | VAC | JaNos | MX,MY | N | Emergency Pump Survey | 18:37 |
18:23 | ISC | Camilla, Matt | LVEA | N | Measuring viewport heights | 18:54 |
18:39 | PCAL | Tony | PCAL Lab | N | TSA to France + stickers | 20:07 |
19:01 | SUS | Jim | LVEA | N | Cabling | 23:00 |
19:31 | FIT | Ryan C | LVEA | N | Respiratory and Perspiratory Regulation Test (Walk) | 20:04 |
19:56 | ISC | Matt, Rahul, Camilla, Oli | LVEA | n | HAM1 ISC installation | 23:23 |
19:59 | VAC | Jordan | MY, MX | N | Turbo Pump Checks | 22:50 |
20:00 | SUS | Betsy | LVEA, Opt Lab | N | Walkabout + Feed Through Cable Work | 21:56 |
20:03 | VAC | Travis | Opt Lab | N | Feedthru Cable Work after turning compressor off | 22:48 |
20:19 | VAC | Janos | LVEA | N | VAC checks | 20:28 |
20:41 | CDS | Fil, Dave | FCES | N | HAM8 Post Outage Glitch | 22:59 |
21:07 | VAC | Vacuum Convoy | YARM | N | Beam Tube Experiment Walkabout | 21:56 |
21:49 | PCAL | Tony | PCAL | N | Measurements and general lab affairs | 22:22 |
22:59 | EE | Fil | HAM1 | N | helping Rahul | 23:24 |
23:24 | SUS | Betsy. Fil, Rahul, Daniel | LVEA | N | RM1 Things | 23:40 |
Ibrahim, Dave:
RM1 exceeded its RMS motion limit, and 5 minutes later the HAM1 DACs were DACKILLed, stopping all h1isiham1 and h1hpiham1 drives.
We have bypassed RM1 and SEI-HAM1 watchdogs indefinitely for now.
RM2 started ringing up, so I've bypassed everything for HAM1 now.
Jennie Wright, Sheila, Keita, Camilla
Jennie has been working on modeling of our arm to OMC mode matching, and while she was looking for some distances we noticed a discrepancy between the as built numbers and the mode matching design. It seems possible that there was a mix up, where design documents call for a distance of 97cm between the OMC waist and OM2, and the as built distance is 97 cm between the OMC input coupler and OM2 (so, the OMC seems to be translated by 14 cm from where the mode matching design expected it to be). If we have the q parameter used in the design (ROC matched to SRM, beam size there is 2.1mm), this would introduce a 1% mismatch between the OMC mode and the SRC mode (the impact could be larger for a different q parameter). Note that the analysis done in 71145 was using the design distances, so we will want to revisit that. I've attached an a la mode script below.
Editing to add more information:
I initially did this with the design ROC for OM2, which is 1.7meters, which is also what is in Finesse. This results in an overlap for the design locations of 99.95% and 99% for the as built locations, with the as built waist location 12cm from the OMC waist location (there are differences in the other distances that partially cancel the 14cm difference between OMC input coupler and OMC waist location), and a waist size of 545um compared to the OMC eigenmode of 509um. In 71145 Keita says that the OM2 ROC is 2m cold and 1.75m hot.
If we change the OM2 curvature for the as built path to 2 meters, the overlap becomes 93.8%, and the waist location becomes 14.3cm from the OMC waist location, with a waist size of 649um. Using the hot ROC of 1.75m, the overlap becomes 98.5% and the waist is 563um 11.5cm from the OMC waist. So, if our q parameter was the design one at SRM, the error in OM2 curvature would be compounding the error in the OMC placement to make the mode matching worse. The single bounce measurements agree that the mode matching is worse with OM2 cold than hot, but the full IFO measurements are the opposite.
Summarizing distances:
T1200410 says we should have:
.yaml file, which is based on E2100383:
Camilla looking at edrawings (which agree with photos):
To compare the solid works to the photos we looked at D0901822 and compared it to OM3 photo and this photo of OM2 when it was a tip tilt.
Using the beam q from table 1 of T1200410 for just after SRM, and propagating it through the distances from T1000317, gives an overlap with the OMC waist of 99.96%. Adjusting the SRM to OM1 distance to agree with T1200410 gives 99.95%, so that difference between the two design documents isn't significant.
Here's a version of the script that I used to make the plot above. a la mode is a matlab beam propagation and mode matching code written by Nic Smith that is available here. If you download that in the control room it will give some errors, I have a copy of the directory I use in matlab2019a in the control room here
S. Koehlenbeck, J. Freed, J. Kissel, J. Oberling, R. Short
The SPI pick-off path installation on the H1 PSL table is now complete. The beam in the new SPI path has been reduced to 20mW and is currently being dumped with a razor dump between SPI-L1 and SPI-L2. Pictures attached reflect the final installation and layout, which will be be reflected in the updated as-built layout at a later date.
Associated entries: 83925, 83933, 83956, 83961, 83978, 83983 (and more to come)
ECR E2400083 IIET 30642 WP 12453 Here's Ryan's birdseye view labeled with all the components. For details of the components, see the SPI BOM, T2300363, exported from its google sheets to -v4 as of this entry.
Tagging EPO for photos.
83996 Power In ALS / SQZ / SPI Paths Post SPI Pick-off Install