Writing this alog on behalf of most of the control room...
After we redid the input matrix for CHARD and INP1 10W, we checked the PRC2 and INP1 bandwidth. We were also concerned about the overall gain of CHARD P and Y since they seemed to be way too low
We decided to power up anyway, and saw that the pitch ADS was able to run fine, now that the CHARD pitch gain was nominal. However, yaw ADS still had problems during move spots.
Everything looked good, so I took us up in power from 25W to 60W, stopping frequently to check for instabilities. We made it, but again the ADS was unstable, so Georgia used the Camera servo guardian to move off the ADS to camera servos, and everything was fine.
I stepped through lownoise ASC by hand, skipping the lownoise steps of CHARD P and Y since those gains were not nominal.
Lots of the of the usual wobbly stuff in the ASC and buildups at high power, but the overall alignment and control looks good: PRG is still around 50 at full power.
We then ran through lownoise coil drivers and the ETMX ESD transition. We had one guardian error at the end of TRANSITION FROM ETMX due to divide by zero error since the convergence checker looks for something that is like [ADS error signal / ADS CLKGAIN] and the ADS CLKGAINs were zero. Georgia and I fooled the guardian by setting the CLKGAINs to 1 momentarily, and then undoing them once the state completed.
We ran all the way through LOWNOISE LENGTH CONTROL, although the LSC feedforward is no longer well-tuned, so I turned it off momentarily so we could check OLGs.
The LSC feedforward is currently so bad that we should go from-scratch when we retune it instead of the iterative method.
We had a fast unknown lockloss while sitting in this state- no one was doing anything and we don't see an obvious cause.
We think we have properly SDFed and guardianized all changes from today.
My only worry: we were not able to raise the CHARD Y gain until we reached maximum power, but obviously we are having ADS stability issues since this gain is too low. Currently I have set the guardian to have what I think is the "correct" CHARD Y gain (300 once all loops are closed), but if it's too high, drop it back to 3.
Recommended to do list:
M. Todd, E. Capote, C. Cahillane
We ran an OLG measurement for LSC-MICH1 loop, once we were in LOWNOISE_LENGTH_CONTROL.
At first we saw that the guardian had not turned off some strange notch filters we did not expect to see.
Craig spotted these as BounceRoll filters, which we turned off and reran the measurement.
Soon after the measurement was done, we lost lock so we are wondering if these notches were responsible or if we need to watch out in other LSC loops.
Now that we're at 60 W of input power, I double checked the ISS secondloop array pointing after the vent. We're missing slightly, seemingly pitched off the ISS QPD. The ndscope has Y1 dashed white lines at where the ISS PD values are now. The ISS secondloop PD values from March 12 are the actual traces. We're still locking, and so I leave ISS picoing undone for now. We'll have to leave the ISS secondloop open and pico back onto the array at some point. Based on the attached PSD, this could be responsible for our huge peak at 29 Hz in DARM.
TITLE: 06/02 Day Shift: 1430-2330 UTC (0730-1630 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: Oli
SHIFT SUMMARY:
Much of today was work in ASC land with H1 locked most of the day at 10W (but started powering up at the end of the shift) and also had the arrival of even more members of the Syracuse LSC Team! But there was also work on the Squeezer toward the end of the day. The plan for tomorrow's Maintenance Day is to continue with Vent Recovery locking work.
Rahul addressed rung up violin modes from this morning and he requested the Oli (EVE operator) to apply these settings new settings (noted in alog 84720).
The day started out with the drama of a fire out beyond End-Y (Fire Dept phoned the Control Room notifying us that they were fighting a fire on SR240 (see attached photo from the roof of the Corner Station).
LOG:
Control Room (Corey, Sheila, Elenna, Oli, Georgia, Craig, Julia, Matt, Keita, Ryan S, Camilla
Notes of what's been done so far today, we've spent the majority of the day locked at POWER_10W, adjusting the ASC sensing matrix and gains:
TITLE: 06/02 Eve Shift: 2330-0500 UTC (1630-2200 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: Corey
CURRENT ENVIRONMENT:
SEI_ENV state: CALM
Wind: 11mph Gusts, 5mph 3min avg
Primary useism: 0.04 μm/s
Secondary useism: 0.31 μm/s
QUICK SUMMARY:
We are sitting in POWER_10W, and have been here for the past several hours. Currently commissioners are still working on the CHARD, INP1, and PRC2 loops, kind of having to swap between all three as they slowly get them better (84711, 84724).
Julia, Georgia, Sheila, Camilla, Elenna
This might be out of date already as some ASC input matrices have already been updated.
On Sunday we had some locklosses as we powered up from a 0.02Hz oscillation. One known issue is we have taken out some gain out of our CHARD loops. We wanted to check our sensing (input) matrices CHARD, INP1 (which both use the refl wfs) and PRC2 (which uses new in vac pop_x).
We sat at 10W, with the input matrix Sheila found last week:
DOF | REFL_A_RF9_I | REFL_A_RF45_I | REFL_B_RF9_I | REFL_B_RF45_I | POP_X_I |
INP1_P | 1 | 1 | |||
CHARD_P | -1 | -0.5 | |||
PRC2_P | -1 | ||||
INP1_Y | 1 | 1 | |||
CHARD_Y | -1 | 1 | |||
PRC2_Y | -1 |
While Elenna measured the phasing using an 8 Hz line, Julia and I added offsets into the loops and looked at the responses in the different sensors.
Some of this is a bit different to what Sheila saw last week, but our ifo alignment has changed. We want to find intrixes that are sensitive to each DOF and ideally are insensitive to the other DOFs.
While writing this another input matrix for INP and CHARD has been put in - https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=84711 - and seems to be working so stay tuned.
We plan to work on our gain heirarchy and hopefully power up further soon!
These are my radar plots for my 8 Hz dither sensing matrix.
Addressed TCS Chillers (Mon [Jun2] 100-125am local) & CLOSED FAMIS #27816:
This morning while Corey and the commissioning team were trying to lock and power up the interferometer, the violin modes were pretty rung up. For most of the modes, I was able to damp them down using nominal settings except three of them which are listed below along with the settings which seems to be working for now.
Made those changes for 2W damping, and will hopefully be able to confirm whether they also work for 60W. For ITMX 03 and ITMY 05, I added new 2W settings for IX3 and IY5. These changes were saved in lsc_params and the violin damping guardian has been reloaded.
FAMIS 31088
No major events of note. The slow changes in PMC TRANS and REFL power seem to follow AMP2 output power.
TJ, Camilla, Checking as Sheila was concerned about this as Georgia/Craig need to move the ITMX SPOT GAIN "CENTER
" 84702.
Attached are the HWS Live plots comparing when we get to 10W and 120s later for ITMX and ITMY now. And also for ITMX and ITMY at our last 10W power up before the vent (note that then we don't pause at 10W and continue increasing power during the 120s).
Can see no obvious new point absorbers, ITMY looks perfect and ITMX has the same point absorbers as before, it;s possible there's a new point absorber on the right of the optics (orange arrow in attached) but it doesn't look scary. We will continue to check this but it's possible that our alignment has just changed (has since 66198) so that we can now see this point.
Sheila and Elenna turned the CO2s on as we were powering up from 10W to 25W. Attached is the 2 minutes after CO2s were turned on while we were sat at 15W for 4 minutes.
Can see the CO2 patterns of ITMX and ITMY. IY CO2 looks good but IX CO2 it looks off in YAW, we should check how this compares to the IFO spot at full power. It would be worth doing some dither tests to see if this needs adjusting.
HAM1 annulus system appears to have issues pumping down, currently its annulus ion pump is railed 10 mA, and the pump cart pumping on this system is sitting at 6.04x10-05 Torr, see attached photo.
Process thus far:
I plan to visit HAM1 to check the rest of the bolts on -Y door and +Y door.
HAM1 internal pressure is doing good, see attached photo of the pressure at the SS-500 pump cart pumping on HAM1. Second attachment is a 5.5 day plot of the pressure internal to HAM1, the large step noted on the plot is due to the introduction of HAM1 ion pump.
(Jordan V., Gerardo M.)
Today we went and performed the following on the annulus system for HAM1:
Now we wait to see the results of today's changes overnight.
M. Todd, C. Cahillane
Yesterday we were interested in some noise we were seeing around 6Hz in various ASC signals (mostly CHARD pitch). This motivated us to look at the RMs, so I took a PSD of each DOF for both RMs. We are not sure why there are such differences in all the dofs, and if there are unintended side-effects to this.
I'm specifically wondering why RM2 has larger peaks around 6.25 Hz in all dofs...
This feature is the primary vertical resonance of the HTTS. The ISI HAM1's control system has still not yet been commissioned, so the decision to *unmute* the HTTS "because the ISI isolation performance should be much better than the Stack" will plague us until that's true. See "muting the HTTS blade springs" ECR E2200181, which confirms the 6.25 Hz resonance. See Integration Issue 33777 for historical notes, specifically Comment 2's record of IIET call discussion and agreement to *unmute*. I suspect the low-frequency performance will also improve once the ISI's controls are commissioned. Let's give Jim some time to figure out how to dance around the ~70 Hz feature that he's dealing with, see LHO:84638 (and last week's lock-acquisition problems do to ignoring it LHO:84640).
For chamber closeout finalization, this morning I * placed a 3" contam control wafer on the center of the HAM1 table today * took a few last pics, removed the stowed 3x septum covers (missed removing the 4th one from the septum, thanks vac good eye, pic 4) * looked around for left behind tools * retraced the beam path to look for errand in-the-way cables (none observed) * inspected under and around lower area of table for left goods (none found) * cleaned up last tool pans to get ready for doors * particle counts were <50 all sizes, zero most often * purposefully coiled the to-be-used in post O4 next vent cable with the peek connector not grounding to anything - it sits in the PSL side door well below the table * all subsytems have signed for doors, so we are putting doors on.
Tagging for epo
Keita, Elenna, Oli, Rahul, Camilla
Summary: Majority of REFL path optics are aligned. Need to beam profile and finish LSC and ASC REFL diode placement on this path and place/check all beam dumps.
This morning, Keita opened the light pipe, locked the IMC but couldn't see the beam as nicely as he did on AS_AIR yesterday. Since that time he had restored PR2 and PR3 to a time we were last locked. He reverted those changes as we could see the beam back at AS_AIR. Checked again IM4 trans QPD was the same as yesterday.
Additionally M16 was placed roughly in the correct position, all optics are now on HAM1 (apart from PM1) and the class-B pans are empty and packed up.
Left IMC locked.
Attaching a bunch of photos of the current alignment:
(I don't have the names of the optics on the SLED so I'm calling them by the order that the beam goes through them)
- Alignment from RM2 onto M5 (attachment1, attachment2)
- Coming from M5, through M6, and onto first lens on SLED (attachment3)
- Coming through first SLED lens onto second SLED lens (attachment4)
- Through SLED lenses and onto first steering mirror (attachment5, attachment6)
- Alignment onto SLED pico mirror (attachment7)
- Top view of pico showing that there is available range in both pitch and yaw (attachment8)
- Distance between L1 and front of LSC REFL A (L1 focal length is 222mm) (attachment9, attachment10)
- Distance from LSC REFL A to M18 (attachment11)
- Distance from LSC REFL B to M18 - needs to be moved closer (attachment12)
About REFL WFS sled:
Tagging for EPO
Oli and I are trying out relocking, and both sitting at 2W and sitting at 25 W (before move spots), I cannot raise the CHARD Y gain beyond 3 without causing some slow growing ~0.8 Hz oscillation in CHARD Y. We will try full power up again with low CHARD Y gain. Turns out the CHARD Y gain was not actually set to 300 at 2W (I only updated lscparams, not ISC_LOCK).
After MOVE SPOTS and reducing modulation depths (but before the rest of the power up), I tried again to raise the CHARD Y gain- same problems.
But once MAX POWER gets us to 60W, I can raise the gain no problem!
I edited MAX POWER to change the CHARD Y gain right at the end of the state (I think).
In terms of setting the time on the ASC convergence in MOVE SPOTS, YAW3 (ITMX spot feedback to PRM) is the culprit that is taking forever.
Oli just took a look back- we usually spend about 5 minutes in move spots, and tonight it is taking more than 10 minutes.
We were able to run through LOWNOISE ASC guardian state fine, so the edits described above work!
We lost lock from a 1 Hz DHARD P ring up that began during the "TRANSITION FROM ETMX" state.
When we went through this state previously and successfully, we were running camera servos instead of ADS. I wonder if that's related to this lockloss.