Thu Mar 14 10:12:31 2024 INFO: Fill completed in 12min 27secs
Gerardo confirmed a good fill curbside.
Pictures of HAM 7 feed throughs D1, D4, D6 and the -Y door as per D1900116 V12. Pictures are in order. First two are D1, three of D4, three of D6.
Pictures of feed throughs on the HAM6 chamber. These reflect the current layout as per D1002877 V14. In order there are three pictures of each D3, D4, D5, D6 and the -Y door.
More pix of WHAM6 D3 flange showing Fast Shutter feedthru and in-air connection.
In addition to and confirming what already reported by Elenna, Camilla and Craig, here's a comparison with a lot of averages of DARM during O4a and now.
TITLE: 03/14 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Commissioning
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 0mph Gusts, 0mph 5min avg
Primary useism: 0.03 μm/s
Secondary useism: 0.35 μm/s
QUICK SUMMARY: IFO requested to be DOWN. Looks like initial alignment trouble after some IM and PR2 moves last night (alog76366). I'll look into reverting the IM1&3 changes as Elenna suggests.
No overnight alarms, WD trips, or other.
Evan, Gabriele, Louis, Swadha, Elenna
After lockloss, we had trouble finding IR and I realized that we likely needed an initial alignment due to Craig's changes of the input pointing today. Running through input align was tough, so we held with Xarm IR locked and Evan walked IM4 and PR2 to the correct alignment. PRC align also needed some help, but the rest of the initial alignment completed well. We successfully locked DRMI with ASC. However, once we moved through the carm offset reduction, we lost lock twice in carm 5 picometers. It appears the alignment is not good on the AS air camera and the arms are not well matched. There are multiple saturation warnings when DHARD WFS comes on.
I think we should revert the IM1 and IM3 changes, and instead use the picomotors to correct the beam pointing on IM4 trans and the ISS array.
[Evan, Swadha]
We are trying to find a way to prevent PR3 angular motion from being impressed onto the test masses by the ASC. We had previosuly attempted unsuccessfully to diagonalize PR3 motion out of the REFL sensing matrix. Since that did not work, we are trying to find a potential error signal for suppressing PR3 motion.
We tried to close a loop around PR3 pitch using POP_A. We took the matlab plant model for HLTS M2 torque to M3 pitch, inverted it, and put it into the PRC1 filter bank (attached for pitch). We then turned on a 1/f filter. Driving M2 with this filter and turning up the gain, we found that the error signal was suppressed but microseism was being impressed onto PR3 as seen in the oplev spectrum (attached). Therefore, POP_A does not seem to be a good sensor.
The attachment shows the appearance of PR3 pitch motion in the REFL WFSs driven at 8 Hz with notches in the ASC loops. Since it shows up with opposite sign in the 9 MHz and 45 MHz signals, while cHard shows up with the same sign in all signals, we had thought we could tweak the cHard error signal (it uses all 4 of A9I, A45I, B9I, B45I) to remove PR3 motion. However, the resulting error signal had increased microseismic motion and motion above 10 Hz (presumably HAM1 motion). This was not placed in loop. There was no discernible reduction in the coherence between the proposed error signal (inserted into CHARD_P_B) and the PR3 oplev.
[Elenna, Gabriele]
We injected broadband DHARD_Y noise and measured the couplig to DARM with different values of the ITMY Y2L gain. As we saw in the past, there are two coupling regimes:
The nominal value of Y2L gain is -1.65, that we found yesterday to be optimal for DHARD_Y to DARM coupling, using a line at 30 Hz.
Today the situation is different, a gain of -0.9 would reduce the coupling above 30 Hz by 20+ dB, at the price of a larger coupling below 30 Hz (where we care for DHARD_Y noise). Between yesterday and today: new OMC alignment, new DARM offloading, new input alignment, so probably it's not a big surprise that the optimal A2L is different.
We left the value to -1.65, since that is the best at frequencies below 30 Hz, where there is still coherence between DHARD_Y and DARM.
With the new OMC ASC offsets, the DHARD Y coherence has changed again. https://ldas-jobs.ligo-wa.caltech.edu/~elenna.capote/brucos/New_OMC_alignment/ASC-DHARD_Y_OUT_DQ.html
The coherence is stronger now from 30-50 Hz, which suggests that we should consider a new A2L that reduces some of that noise injection. To quote Gabriele "perhaps we could find an intermediate value that reduces some noise 30-50 Hz without making the 10-30 Hz noise much worse"
Camilla took some quiet time this morning (alog 76324), so I reran the correlated noise budget. The actual noisebudget traces here are eclectic, some old, some new, most are probably still from December. Still we wanted to see if our correlated noise had changed since then (alog 76213), and the short answer is not really. March 13 2024 Correlated Noise interactive svg I couldn't tell what to make of this, so I compared it to our December 2023 correlated DARM. Here, we can see our correlated noise floor at 500 - 600 Hz is moving slightly. If true, then it's probably not a thermal noise floor. It's not so easy to tell if this is a calibration error, the calibration lines seem roughly similar between the two noise curves. If this is true, then it's possible our laser noise is movely slightly, or it's something else entirely that is still not well-understood.
Craig, Jennie W.
In order to calibrate POPAIR_RF9 and RF18 PDs in terms of PRG9 and 45, we ran Craig's labutils/mod_depth_up_down_test.
We realised our mod depth up/down test from the other day was changing the gain of the POPAIR diodes to compensate the drop in optical gain as the modulation depths are changed.
We don't want this as it negates the change on the diodes we are trying to measure for our calibration.
Craig commented out these lines in the step_9 and step_45 functions.
We also were overestimating the PRG as the beam on IM4_TRANS PD was not well-centred.
In this log we stepped the alignment in lock to optimise on the IM4 TRANS QPD and the ISS array.
The mod-up-down-test was taken during low frequency measurements of new DARM.
Times RF9 was stepped down are 1394406378 GPS, then back up at 1394406438 GPS.
Times RF45 wa stepped down are 1394406448 GPS, then back up at 1394406508 GPS.
After this test Craig did more optimisation of the input alignment with IM 1 and 3.
Then I waited a bit and took another test. Both were done with a well thermalised IFO of more 10 hours lock.
Times RF9 was stepped down are 1394409674 GPS, then back up at 1394409735 GPS.
Times RF45 wa stepped down are 1394409744 GPS, then back up at 1394409804GPS.
First image is beam diverter that needs unshuttered for this test.
Second image shows the plots from the first test, third image shows the second test.
Results from the second scan, taken starting at 1394409654 and going to 1394409887:
| Channels | 9 MHz | 45 MHz | Carrier |
|---|---|---|---|
| H1:IMC-PWR_IN_OUT16 | 0.013 | 0.015 | 0.972 |
| H1:IMC-IM4_TRANS_NSUM_OUT16 | 0.013 | 0.015 | 0.972 |
| H1:LSC-REFL_A_LF_OUT16 | 0.040 | 0.048 | 0.912 |
| H1:LSC-REFL_B_LF_OUT16 | 0.035 | 0.042 | 0.924 |
| H1:LSC-POP_A_LF_OUT16 | 0.017 | 0.008 | 0.975 |
| H1:ASC-POP_A_NSUM_OUT16 | 0.017 | 0.009 | 0.975 |
| H1:ASC-POP_B_NSUM_OUT16 | 0.017 | 0.008 | 0.975 |
| H1:ASC-AS_C_NSUM_OUT16 | 0.176 | 0.493 | 0.331 |
| H1:ASC-OMC_A_NSUM_OUT16 | 0.177 | 0.609 | 0.213 |
| H1:ASC-OMC_B_NSUM_OUT16 | 0.179 | 0.539 | 0.282 |
| H1:ASC-X_TR_A_NSUM_OUT16 | 0.004 | 0.006 | 0.990 |
| H1:ASC-X_TR_B_NSUM_OUT16 | 0.004 | 0.006 | 0.990 |
| H1:ASC-Y_TR_A_NSUM_OUT16 | 0.004 | 0.007 | 0.989 |
| H1:ASC-Y_TR_B_NSUM_OUT16 | 0.004 | 0.007 | 0.989 |
Power-recycling gains for sidebands and carrier
9 MHz PRG = 64.7
45 MHz PRG = 27.8
Carrier PRG = 49.6
Reflection ratios for sidebands and carrier
9 MHz reflection ratio = 0.198
45 MHz reflection ratio = 0.205
Carrier reflection ratio = 0.060
Jennie, Matt Todd, Craig
TL;DR We restored the alignment from O4a onto the ISS QPD array and IM4 Trans by moving IM1 and IM3
This has recovered the full-lock input-on-the-PRM power from 54.5 W to 57.5 W.
We are probably in a spot where we can trust Keita's IM4 TRANS calibration from alog 62213 again,
meaning we can trust our PRG of 50 W/W.
History
I tried doing this yesterday (alog 76291), but we were worried about changing the input alignment while not in lock.
Later, Sheila tried picoing onto the ISS Array (alog 76303), but undid her changes when they were causing us to fall off the array.
Alignment
Loosely, we wanted to restore the alignment we had at the end of O4a.
Centering on the ISS QPD is not necessarily the best for the alignment onto the actual ISS Array.
Additionally, the ISS QPD dofs are flipped (PIT is YAW, YAW is PIT).
I started moving IM3 and IM4 in conjunction to center the QPDs, but this didn't work because we were moving too much on the ISS QPD and not really moving on IM4 TRANS, to the point where we were falling off the diodes in the array.
So after that, I started moving IM1 and IM3 with much better results, pitching up with IM1 onto IM4 TRANS, then recovering the ISS QPD with pitching down IM3.
We ended up at the below alignments:
Epoch GPStime Sensor Pitch Yaw
---------------------------------------------------------
O4a 1389013541 ISS QPD -0.62 0.72
IM4 TRANS -0.44 -0.34
Pre-O4b 1394409800 ISS QPD -0.54 0.75
IM4 TRANS -0.02 -0.20
This afternoon, our high frequency DARM, above 4kHz, improved. Plot attached. This was during these IM moves, also had we swapped to the NEW_DARM configuration (so low frequency calibration is incorrect) and had moved the OMC 76335 this AM.
This high frequency DARM then again increased with seemingly no IFO changes. Using the aligoNB ISS_excitation_LF.xml template with no excitation, we could show that there is high coherence between DARM and the 2nd loop ISS: plot.
It looks like the alignment on LSC_POP changed or started clipping during this IM move. This morning TJ is reverting the IMs, (and PR3), before starting an initial alignment.
Here are some extra trends during the in-lock input beam walking yesterday.
The cursors are where the beams were during the last lock of O4a.
There is a lot of plots so the second and third attachments are just the same plots but zoomed in to the SUS alignments, and the PD signals.
TITLE: 03/13 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Commissioning
INCOMING OPERATOR: None
SHIFT SUMMARY: Lots of good commissioning time today since H1 was locked all day (current lock stretch up to 14 hours).
LOG:
| Start Time | System | Name | Location | Lazer_Haz | Task | Time End |
|---|---|---|---|---|---|---|
| 15:53 | FAC | Mitchell | LVEA | - | Pictures of HAM6 | 15:59 |
| 15:57 | SAF | HFD | X-arm | - | Controlled tumbleweed burns | 20:54 |
| 16:53 | SQZ | Nutsinee | LVEA | - | TF at SQZ racks | 17:06 |
| 17:02 | FAC | Karen | Opt Lab | - | Technical cleaning | 17:21 |
| 19:38 | CDS | Fil | MX | - | Troubleshooting access cameras | 20:38 |
| 21:06 | FAC | Tyler | X-arm | - | Checking burn progress | 21:17 |
| 22:49 | FIT | Gabriele | Arms | - | Running | Ongoing |
No SQZ time taken this morning 15:29UTC to 15:51UTC. There was small glitches at 15:35:37 and 15:41:53. Best stretch of time is 15:42:00 to 15:51:00. Took no sqz time with hot OM2 in 74834 / 74640, Cold OM2 Dec 20th 18:00- 18:18UTC 74935.
Minhyo
I compared the DARM sensitivity with NO SQZ and OM2 cold condition between today's morning and one in O4a (20/12/2023, 18:10 UTC)
(Also refer to Elenna's alog: 76277)
Seems that the sensitivity don't show much difference above 100 Hz, but noise went up in low frequency.
Other no SQZ times taken yesterday:
I was able to request and transition to the new DARM state without issue. ETMX still saw a pretty large kick. I'll have to circle back re: how large compared to previous attempts. We will also want to take a look at any effects moving the integrator on L2 LOCK L had. Note: We do get a few SUS_PI warnings shortly after transitioning to this state. Quiet time to monitor for non-stationarity: Start GPS: 1394344327 Stop GPS: 1394346169 Turned off cal lines at GPS 1394346770.39 Elenna started a Bruco after the cal lines were turned off. here is a screenshot of DARM in the new configuration. 20-90Hz looks high and below 15Hz looks low. It's hard to tell how much of this is real until CAL-CS is calibrated & that calibration is propagated to the DTT template. I started an L2 LOCK IN1/IN2 injection using noise recorder at 1394347034.426. We used a tuned broadband measurement that Craig and I put together. Apparently it was too strong because we lost lock from this injection. It also tripped EX. I requested DOWN and the EX trip alarm reset.
Bruco is here: https://ldas-jobs.ligo-wa.caltech.edu/~elenna.capote/brucos/New_DARM/
Just from first glance looks like some residual LSC coherence, but not enough to explain the strange shape of New DARM.
Here are plots comparing the MASTER OUTS on ETMX during Louis's quiet time here with L3 offloaded, vs Gabriele's quiet time in alog 76278 during Nominal DARM. We are concerned only with the filter changes that Louis and Sheila made to offload more of L3's length actuation onto L2. Because L2 is used to control both length and angular degrees of freedom, it can be easy to ask too much of L2. This lock seems to indicate that this configuration is fairly stable. I looked at the UL MASTER OUTs for the L1, L2, L3 on ETMX. 1) RMS on L3 drives is halved. There is much less L3 drive from 1 to 6 Hz, which dominates the RMS. 2) L2 drives are largely unchanged. 3) L1 drives are changed, but the RMS remains similar. There is much less HF content in the L1 drive with L3 offloaded, and the shape of the resonances around 3 and 6 Hz is altered. Overall it's hard to tell which stage is picking up L3's slack from these PSDs. I believe the intention was to offload to L2, but we don't see any obvious change in what control signal is being sent to the L2 stage. This could simply mean that the angular controls are relatively stronger in the L2 controllers. We'll look at the DRIVEALIGN signals to try and figure that one out quantitatively.
The new DARM loop configuration reduces the DARM noise non-stationary at low frequency.
First plot compares the ESD drive with the Old DARM and the New DARM, confirming that the RMS is significantly reduced, especially at the relevant frequencies.
Second and third plots are spectrograms and whitened spectrograms of GDS-CALIB_STRAIN in the two configuration. Despire GDS-CALIB_STRAIN being wrongly calibrated with the New DARM, it is clear that the low frequency non stationarity is gone in New DARM.
Last two plots are the bicoherence of DARM with the ESD drives, showing that in the Old DARM there is still some bicoherence for noise in the 10-30 Hz region, while in the New DARM this is gone.
These transitions last night were made with a different L2 LOCK filter (which is in L2 LOCK L FM6, replacing the filter used in earlier new DARM configurations that was at FM2). The attached screenshot shows the filter change, I replaced the poles at zero with poles at 0.03 Hz to get rid of the integrator here without changing the phase at the crossover much. This was done with the guardian version 27211
Plots of the actuators during the transitions are attached, here and here, they can be compared to the one that Louis posted where we used L2 LOCK FM2. This suggests that the change to these poles didn't help to reduce the transient during the transition.
Today we tried another change to the transition, this time Evan and I moved the poles in L2 LOCK L from 0.03 Hz to 0.1 Hz, and changed the ramp time for the transition to 10 seconds (from 5). The model is shown in the attached PDF where the new filter is in place in the transition traces. This transition wasn't smoother than the others, see here.
The new UGF is 70 Hz with 20° of phase margin. The crossover between L2 and L3 is at 18 Hz with probably about 40° of phase margin (low coherence due to interference with calibration lines). We have not measured the L1 to L2 crossover yet.
S. Dwyer, E. Capote, E. Hall, S. Pandey, L. Dartez
Here are some notes from our efforts to measure IN1/IN2 at the L1 LOCK L input.
- Sheila adjusted UIM measurement template for new darm config. This template is at /opt/rtcds/userapps/release/lsc/h1/templates/DARM/UIM_crossover.xml.
- Evan ran the template initially and saw that the UGF is near 1Hz. He adjusted the excitation amplitude along the way to improve coherence for the next time we run this measurement.
- Evan added a high pass filter in the L3 DRIVEALIGN bank with a cutoff frequency at at 5Hz
- first filter attempt was at 8Hz; possibly caused a roll mode to excite near 13.75Hz
- second filter attempt was at 5Hz; this seemed to improve the roll mode excitation
We ended up losing lock a shortly after the injection finished due to PRC activity.
Comparison of DARM ESD drive from end of O4a versus a few days ago. The microseism was about 0.2 µm/s in both cases. The rms DAC drive from 0.1 Hz to 0.3 Hz is about 400 ct, so even in cases of exceptionally high microseism it will be subdominant to the 7000 ct rms that is accumulated above 1 Hz.
Naoki, Vicky, Nutsinee, Matt
We recovered the FDS and got 4.5dB squeezing in IFO with 40 times more CLF power as shown in the attached figure.
First we restored the ZM1/2/3 and FC1/2 OSEM positions to the values in O4a. Then we found the FC green trans in camera and PD. We aligned FC1 and FC2 and successfully locked the FC green. We went to SQZT8 and centered the green camera and green QPD.
Since we aligned the green QPD, the green QPD offset value is not valid anymore so we removed the beam spot control from FC ASC. We made a flag for the beam spot control in sqzparams and it is set to False now. We also set the ADF servo flag to False since the ADF demod phase might not be correct. After we figure out the optimal green QPD offset and ADF demod phase, we should revert them.
We reduced the FC IR gain from -3.5 to -0.1 and reduced the FC ASC gain from 0.1 to 0.005.
We have not done any PSAMS scan so we will do it next week.
I reduced the FC ASC threshold as shown in the attachment. I also reduced the fcWFS_qDip_lock_threshold in sqzparams from 0 to -50000 although I am not sure if this is useful.
The SQZ-CLF_REFL_LF_OUTPUT is 245uW now and was 5.7uW in O4a so the CLF power is 43 times more now.
Since the vent, we haven't recovered our squeeze in the region of that really improves our range: See Yellow BLRMS around 350Hz.
Checked SHG pump launch is ~20.5 - 21mW at both times and OPO green trans rejected is similar.
Trending our other signals, just see that OMC_TRANS_RF3 and CLF_REFL_RF6 and FC_WFS_A_ locking signal sare much larger, I think this is expected from increased CLF power. The NLG is simular 15.8 now, was 17.3. Plots of Jan 10th and March 9th.
