Since H1 has been running suprisingly stable (no PIs rung up [speak of the devil---28 perked up as I typed] & SRC1 has been servoing fine), I went ahead and addressed DIFFERENCES on the SDF. Going a node at a time, below I list how many DIFFS each had, and also give a summary note about them as well. Attached you will also find a snapshots for all the DIFFs before I made them GREEN (well, except for SUSETMY...I forgot to snap one).
I reckon some of these will be RED again soon due to changes: PI's always change, Calibration may change, etc.
SUSIM: 1 Total Diffs
ACCEPTED: TRAMP for IM3 Pit
LSC: 6 Total Diffs
ACCEPTED all Gain changes.
ASC: 33 Total Diffs
ACCEPTED: PRC2_Y Filter difference, POP90 Gain, a few offsets, many matrix element changes, and many ODC channels.
REVERTED (2) TRamps
OMC: 3 Total Diffs
ACCEPTED: ODC channels
PSLISS: 1 Total Diffs
ACCEPTED: Ref_signal (has been moving around last few days)
ISIETMX: 9 Total Diffs
ACCEPTED all 9 filter changes (this is due to no BRSx for next few days)---For these Seismic SDFs, we probably want to update these when we are back to nominal environmental conditions and have BRSx back. Since the SEI Config could change a bit depending on weather & health of BRS's, will we NOT monitor these?
SUSETMX: 1 Total Diffs
ACCEPTED: GAIN for the L1 Lock Gain of ETMx (its nominal WAS 0.0)
SUSETMY: 2 Total Diffs (forgot to take snapshot!)
ACCEPTED: P2L & Y2L TRAMPS
ALSEX: 3 Total Diffs
ACCEPTED: These are all "EXTRA_AI" ??
ALSEY: 3 Total Diffs
ACCEPTED: These are all "EXTRA_AI" ??
SUSPROCPI: 4 Total Diffs
ACCEPTED gain & phase changes
CS ECAT PLC1: 8 Total Diffs
All related to "pico"
CALCS: 1 Total Diffs
Value for Pause
CALEX: 1 Total Diffs (forgot to take snapshot!)
Value for SINGAIN
"Slowly but surely..." I'll need BSC8 access in the morning and again tomorrow evening. Check out the attached image. This looks like a step response that couldn't be the result of a real pressure change. I would guess it has something to do with the shared 24 DC supply between PT180 and PT120B and that pulling the fuse for PT180 changed the supply's load - or something - but nothing related to heating the PT180 hardware.
TITLE: 11/25 Eve Shift: 00:00-08:00 UTC (16:00-00:00 PST), all times posted in UTC
STATE of H1: Lock Acquisition
OUTGOING OPERATOR: Ed
CURRENT ENVIRONMENT:
Wind: 22mph Gusts, 15mph 5min avg---> Hoping it doesn't get windier!
Primary useism: 0.06 μm/s
Secondary useism: 0.66 μm/s---> this is pretty high. Hope it stays flat or (obviously drops)
QUICK SUMMARY:
Ed, Kiwamu, Sheila (on phone)
The attached is the new AS36 I matrix which was able to stabilize the SRC1 loop, at least for 30 minutes. I changed only one element, SEG3 -> PIT element. It was -0.487 and now -0.6. Before this modfication, Ed and I closed the SRC1 loop with the old element. Seemingly issue was in pitch which ran away very slowly on a time scale of 5 minutes or so. We then opened the pitch loop and manually aligned SRM so that it maximizes the AS90/POP90 ratio. Then, looking at the error signal, we have determined the desired value for the element. No physics involved.
For OPS,
If the SRC1 loop is still unstable or slowly drifts (which should be visible as increased POP90 on the striptool), the first action should be to open the SRC1 loop by simply zeroing the loop gains.
17:10 Waiting at NOISE_TUNINGS. Losing recycling gain (AS90 over POP90) trace. Turned off SRC loops turned off as suggested by Nutsinee to try and hand align SR2.
17:15 ...never got to try aligning SR2 - LockLoss
21:10 aaaaand we're back. Initial alignment
21:15 Jim W on site.
21:25 Jim headed down to EX to deal with BRS
22:40 Jim headed back from EX. Begin locking.
00:00 Kiwamu has H1. Handing off to Corey
I came in today to see if I could resurrect BRSX, but I was unsuccessful. I re-enabled the damping at one point to see if it was still working and after a while the damper table seemed to just stop servoing. I also damped the BRS by hand a couple times, but it would ring back up, for no apparent reason. It's all very strange, I'm not sure whats going on. I am going to turn a couple of sensor correction taps off to keep operators from accidentally engaging the BRS, until I have a chance to talk to Krishna about how to fix BRSX.
For now, I have defined a couple of states for SEI_CONF to help keep the IFO running. There is a WINDY_NOBRSX_V2, that puts ETMX on 45 mhz blends, but keeps the other chambers on their 250mhz blends with low freq sensor correction. There is also a USEISM_MOD_WIND_NOBRSX, if the wind is low and microseism is too high.
IMC trends showed substantial movement in Pitch from the lock 12 hours ago. Clearing the WFS histories got it re-locked. ASC re-aligning.
MC1 - 7µrad
MC2 - 19µrad
MC3 - 3µrad
≈19:02UTC the wave arrived. All arm ISIs tripped at 19:07.
During large earthquakes operators should try changing the SEI_CONF state to LARGE_EQ_NOBRSXY before any ISI's trip. This should make the ISI's more resistant to tripping, hopefully reducing the amount of realigning you have to do when you try to start locking. Once the .03-.1 hz motion has come back down to 1 micron or less you should try one of the other earthquake states. When the .03-.1 hz motion is back down to around .2-.5 microns, you should be okay to switch to Windy (or whatever state is appropriate for the conditions).
TITLE: 11/24 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Locking
OUTGOING OPERATOR: Nutsinee
CURRENT ENVIRONMENT:
Wind: ~17mph Gusts, 20mph 5min avg
Primary useism: 0.15 μm/s
Secondary useism: ~0.71 μm/s
QUICK SUMMARY:
TITLE: 11/24 Owl Shift: 08:00-16:00 UTC (00:00-08:00 PST), all times posted in UTC
STATE of H1: Meh
INCOMING OPERATOR: Ed
SHIFT SUMMARY: Anamaria left couple of suggestions of things that I can do to help improve the range. I was going to try for an hour but caused a lockloss in the process. Have been having trouble locking all my shift. There're only two ISI configurations I could try without using BRSX (which is still rung up). USEISM_NOBRSXY took me the furthest towards NLN (I was in NLN once with this configuration) but it seems unstable at ~37 mHz.
LOG:
9:08 Lockloss as I tried to engage SRC1 P. Not sure how. I think that's because I forgot to turn on the -20dB filter and turn off the integrator. Sorry. I was going to try moving SR2 and hope that SRM follows.
10:12 Locklosses couple of times during PRMI to DRMI transition. Turned out SRM pitch got stuck in some bad alignment. I moved SRM during PRMI locked then transitioned. ASC was able to engage without issue.
10:18 Lockloss 1 minute into NLN.
10:48 Lockloss the twice at SWITCH_TO_QPDs.
11:13 Lockloss at CARM_ON_TR. I wonder if the useism and wind is becoming a problem.
11:25 Another lockloss at SWITCH_TO_QPDS.
~11:50 Tried to engage BRSX after another lockloss at CARM on TR but it's still rung up. Reverted the configuration to no BRX.
12:02 Tried switching to USEISM_NOBRSXY. It's not in the reccomend list. But with BRSX rung up I kinda run out of options.
Made through SWITH_TO_QPDS with USEISM_NOBRSXY configuration
12:30 Arrived at NOISE_TUNINGS. Staying here for half an hour.
While staying here I noticed AS90/POP90 dropped suddenly. I tried several things to improve AS90/POP90. Moving SR2 seems to work. See alog31813
13:08 Run a2l
13:14 lockloss.
13:27 Went to LVEA to toggle noise eater. Checked with LLO ops (Jeramy)
13:50 Kyle to BSC8 to continue his work from yesterday.
14:32 Kyle out
14:41 Lost lock a few times at PRMI_LOCKED and DRMI_LOCKED. Tidal seems unstable. Recently lost lock at SWITCH_TO_QPDS. I'm switching the seismic config back to Windy no BRSX
15:12 Switching ISI config back to USEISM_NOBRSXY after 3 locklosses at FIND_IR. Wind reached 20 mph.
15:39 Lockloss at LOWNOSIE_ASC (IMC-F ran away at 37 Hz). PRMI striptool screenshot attached.
(see WP #6332) ~0605 - 0630 hrs. local -> Kyle in and out of LVEA Attempted to de-energize PT180 by removing the fuse at terminal #111 in the Y-arm vacuum rack. Noted that the old PT180A signal wiring had been lifted from the terminal strip and was deliberately zip-tied out of the way. The cabling to PT180B was still landed having only the black conductor fused at terminal #111. Curiously, the indicated pressure value on the MEDM screens did not change as the result of removing this fuse. Next, I removed the external gauge electronics, isolated PT180 from the site vacuum volume via closing the 1 1/2" metal-sealed isolation valve and then opened the pump port valve so as to pump the PT180 volume with the locally mounted turbo. Heating was started with the initial variac settings of 20%. Unfortunately, we are using the BPG402-SE version of this gauge - where the "S" indicates "short" nipple. This limits the gauge bake temperature to a modest 80C as measured at its CF flange as the internal PCB can't be thermally radiated at greater temps. This may be a significant limitation as the current theory is that water vapor is the source of the undesired gauge behavior and a relatively short duration bake at relatively low temperatures won't likely remove very much water. (I can cheat a little and adjust the non line-of-site surfaces to much higher temps.) SUMMARY: Disregard the indicated pressure value shown for PT180 as it is not valid (the value at the time of gauge de-energization is latched in Beckhoff?) Also, I will need access to the LVEA later this evening and twice tomorrow, Friday, to make measurements and adjustments.
As I was sitting at Noise Tunings I noticed AS90/POP90 suddenly dropped. First I tried adding some offsets to ASC SRC pitch. I couldn't make a different. Moving SRM also seems to have no effect but moving SR2 I was able to improve AS90/POP90. But something kept dragging SR2 back to where it was in both pitch and yaw (bad place). Anamaria mentioned that she turned off SRC during the last lock strech so I tried and SR2 suddenly came back to its happy place. I was able to put AS90/POP90 back to where it was.
Kept losing lock during switch to QPDs. I wonder if useism+wind is a problem now (useism has reached 1 um/s while wind is ~10 mph). It seems to help the detector stay longer in the state if I sit at TR CARM a little. I will try to stay there a little longer. Switched ISI config to USEISM_NOBRSXY and was able to move on.
John Z, TJ, Andy, David S, Ansel, Young-Min, Jess
Summary: ETMX optical lever laser glitches are coupling into h(t) and causing high signal-to-noise ratio single-ifo burst and CBC triggers. We suspect the op lev sensor is coupling to h(t) through a damping loop for the L2 stage, as large spikes in the op lev laser power are coincident with spikes in L2 OSEM actuation in addition to h(t) glitches.
Suggestion: The ETMX op lev laser or power supply should be swapped out ASAP.
Hour-long clusters of glitches at 10-20 and 30-60 Hz were first noticed on Nov 18 in during a DQ shift earlier this week. The glitches seem to appear sporadically and can be seen in Omicron triggers on Nov 18 at about hours 12:00 and 18:00 UTC. The hveto algorithm, which looks for coincidence between glitches in h(t) and glitches in auxiliary channels, found the ETMX optical lever channels to be significantly correlated with these glitches. (Note the EX SUS rack magnetometer witnesses these glitches as well.)
Attached are two examples from Nov 18 of h(t) glitch correlation with spikes in ETMX optical lever laser power and L2 suspension control.
One of these optical lever glitches was the loudest single-ifo CBC trigger for LHO on Nov 22. They characteristically appear to be a few seconds long in h(t) and broadband, with similar time-frequency content to the optical lever PD signals: [h(t), optical lever (pitch)].
TITLE: 11/24 EVE Shift: 0:00-08:00 UTC (16:00-0:00 PST), all times posted in UTC
STATE of H1: PEM Calibration
INCOMING OPERATOR: Nutsinee
SHIFT SUMMARY:
PEM Injections for the 2nd part of the shift. Range was not the best (i.e. around 60Mpc)
LOG:
We have known for some time that the indicated level of CP4's LN2 fluctuates too rapidly to be physically likely and is more probably due to some transient GN2 phenomenon which effects the validity of the differential transducer. Occasionally this indicated level will deviate enough as to enter into the alarm region and will then get the attention of the CR operator (Corey just asked about this). I guess we'll need to investigate this more seriously. Chandra is aware of this issue but is gone until next week. The Vacuum Team gets notified via automated text messages of these alarms. Until this gets resolved, CR operators only need contact the Vacuum Team Members if CP4 stays in alarm for a prolonged period (say hours).
Note to self: Confirm that the valve that routes LN2 from the dewar through the Ambient-Air vaporizor is fully closed.
Frequently I find that SRC will not lock properly. I then misalign SRM and look at the spot centering on te ASC_QPD to check the alignment of SR2. Usually I find that it's been driven off diagonally in one direction or the other making it difficult for the loops to align and converge SRM into the cavity. After re-centering I will re-align SRM and re-request SRC_ALIGN and it should lock and converge properly. Maybe some hand alignment will be necessary.
Just a minor note---the QPD one looks at is the AS_C QPD. (i.e. Anti-Symmetric port "C" QPD & not the ASC QPD).