When I arrived the IFO wasn't looking good, H1:LSC-POP_A_LF_OUTMON had been dropping in power since ~5UTC and the control signals were all over the place. The DARM spectrum wasnt looking good below 70Hz or so. EX ISI had a large amount of movement in it, but the dropping POP power and lack of useism doesn't explain our usual blends ringing up. I decided to try changing the blends anyway, mainly because it was the only idea I had. This calmed the ASC slightly but a few minutes later AS90 started to dive and then lockloss.
This seemed to have happened a month ago (alog23941).
Now out of lock, we resumed the SDF monitoring of the PMC REF V channel, restored the original 1.34615V setting as per Jason, and accepted it in SDF.
Title: 1/2 Eve Shift 0:00-8:00 UTC (16:00-24:00 PST). All times in UTC.
State of H1: Observing
Shift Summary: Locked in Observing for my entire shift. However, we have witnessed a brief drop in range and ringing up of ASC loops and tidal signals (see earlier aLog 24645) in the middle of the shift. Towards the end of the shift, we have seen a drop in transmitted power via H1:LSC-POP_A_LF_OUTPUT (see attached screenshot) that is very reminiscent of a situation for which I was also the on-duty operator. Perhaps is it coincidental, but this earlier instance of these issues occurred EXACTLY one month earlier (see aLog 23921 for related evidence of the tidal relation amd aLog 23941 for the analysis and comparative plot). If Jenne's conclusion still holds true, sorry TJ!
Incoming operator: TJ
Activity log:
0:17 Betsy to optics lab
1:38 Betsy out
3:46 Ringing up of ASC loops is noticed and DIAG notification of tidal approaching its limit, range degrades ~15 MPc
4:04 ASC loops ring down and range returns to normal
We noticed that the range had dropped and the ASC loops had rung up. Guardian DIAG was also notifying us that the tidal control was nearing its limits at both ETMx and ETMy. While digging through the aLog for solutions (and finding only speculative fixes involving switching of ISI blends), things seemed to have calmed down and returned to normal. However, plotting the TIDAL_CTRL signals for both X and Y shows that the control signal is much larger than we have seen in quite some time. The first plot is a 2 day plot of the TIDAL_CTRL signal for both arms, and the second is a 30 day plot.
We are not sure we understand why Guardian DIAG is throwing the 'within 10% of its limit' notification. The control signal for both arms is ~300 while the limit for both arms is set to 700.
Activity Log: All Times in UTC (PT) 00:00 (16:00) Take over from TJ 21:20 (13:20) SDF difference on EY ECAT PLC2 – Called Sheila (see aLOG #24640) 21:35 (13:35) Kyle – On site to over fill Mid-Y CP3 22:20 (14:20) Kyle – Leaving site 22:29 (14:29) GRB Alert – In 1 hour hold. LLO down. 23:30 (15:30) Stand down from GRB alert hold 00:00 (16:00) Turn over to Travis End of Shift Summary: Title: 01/02/2015, Day Shift 16:00 – 00:00 (08:00 – 16:00) All times in UTC (PT) Support: Vinny, Sheila, Incoming Operator: Travis Shift Detail Summary: Fiber Wrong Polarization was getting very close to limit of 40. Trend shows swings over time. This will not affect the IFO while in lock, but could make relocking difficult if still high. At shift end, this had dropped to around 32. OK shift – In Observing mode for full shift. Environmental conditions were good for the shift. Range was in the high 70s to low 80Mpc for the shift. There were several (15 plus) ETM-Y saturations, which knocked down the range a bit. It has stopped snowing. Since it was a dry light snow, there was not much accumulation. Still very cold at the site – around 18F.
Looking at the spectrograms and glitchgrams on the summary pages for January 2nd there seems to be some interesting behaviour from about 10 - 35 Hz at LHO. The noise drops in this band over the course of the day and glitches in this band become less frequent as well. It does not seem to correlate to wind speed or ground motion, at least not in an obvious way. Looking at the ground motion BLRMS page of the summary pages, there do seem to be some spikes between 4 - 6 UTC, in multiple bands. However these spikes are relatively short-lived and the noise in the spectrograms starts before that. I've attached a few images showing noise and glitches from the band of interest.. The plots are also visible on the summary pages.
The last lock loss on 1 Jan was due to PSL issues (see alog). The low frequency noise reported here seems to be correlated with unusual noise in PSL ISS and also shows up in IMC frequency noise. The attached pdf shows apparently normal behavior on 1 Jan for PSL ISS, IMC frequency noise, and strain followed by excess noise in all three on 2 Jan. While things appear to have calmed down on 3 Jan (so far), there appears to be a PSL glitch that shows up in the strain channel.
Noticed SDF was showing a difference for EY ECAT PLC2. The fiber temperature control had switched off at 12:50. Called Sheila. While talking to Sheila noticed two other channels related to fiber temperature were cycling on an off. Sheila said this would not be a problem maintaining lock but could be a problem for relocking. Sheila noticed that the Fiber Wrong Polarization percentage was close to its limit of 40. It was between 37 and 39 percent. This should not be a problem while we are locked, but should be addressed at the next lockloss.
This is all related to the lock of the auxillary laser at the end station to PSL light transmitted through the fibers. The beckhoff automation tries to keep this locked at all times, which saves a small amount of relocking time and also some hastle compared to just letting this laser drift while the IFO is locked. This laser is shuttered while in full lock, and should have no impact on the IFO.
What Jeff noticed is that the automation stops trying to lock this and sends errors if the polarization of light coming out of the fiber has drifted by 40% or more. This is a problem that should probably be addressed next time we unlock by following the instructions here : https://lhocds.ligo-wa.caltech.edu/wiki/Troubleshooting%20the%20IFO#ALS_Fiber_Polarization
While everything is behaving as intended here, and it seems good that our automation gave Jeff an early warning about the polarization drift which could prevent relocking if not fixed, this would be a problem if Beckhoff SDF were integrated into the intent bit.
Noticed dewar vapor pressure indicating 10 psi which is lower than what I had remembered for the nominal value for this dewar -> Exhaust check valve bypass opened, LLCV bypass opened 1/2 turn ccw, LN2 appeared exiting pipe after ~45 seconds -> let fill for ~2 minutes
IFO has been locked and Observing for the past 6.5 hours. PSL power is holding at 21.7W, range has been moving around a bit due to several ETM-Y saturations, but is mostly in the high 70s to low 80Mpc. These saturations do not appear to be associated with RF45 glitches. The wind is running at a light to gentle breeze (4-12mph). It is currently snowing and starting to accumulate. Seismic plots are mostly flat and within normal operating bands. The EY Y-axis in the 0.03-0.1Hz band has been climbing over the past 2 hours. Microseism looks normal and is centered around 0.3um/s.
O1 day 106
model restarts logged for Fri 01/Jan/2016 No restarts reported
Transition Summary: Title: 01/2/2016, Day Shift 16:00 – 00:00 (08:00 – 16:00) All times in UTC (PT) State of H1: 16:00 (08:00), IOF up in Observing mode for last 2.5 hours. Range and power are normal. Environmental conditions are good. Outgoing Operator: TJ
Title: 1/2 OWL Shift: 08:00-16:00UTC (00:00-8:00PDT), all times posted in UTC
State of H1: Observing at 78Mpc for 2.5hrs
Shift Summary: One lockloss from an unknown cause, but I got it back up with only a few minor hickups.
Incoming Operator: Jeff B
Activity Log:
Had to run through an initial alignment where Mich dark locked would not lock, then some trouble with the PRMI to DRMI transition. But now we are up and observing!
Not sure of the cause; the control signals all looked good, nothing on the seismometers, wind low, need to further investigate after locking.
Title: 1/1 Eve Shift 0:00-8:00 UTC (16:00-24:00 PST). All times in UTC.
State of H1: Observing
Shift Summary: Started the shift with the PSL down and being worked on by Jason and Corey (T. Vo was covering OPS duties). Within the first hour of my shift, they had completed their work and I began initial alignment. After a surprisingly straightforward alignment and locking, made it to NLN at 2:29 UTC. Other than some excess noise from 10-30 Hz, range has been the typical ~80 MPc for the past 6 hours. Environment is calm.
Incoming operator: TJ
Activity log:
In addition to the PMC diff that Betsy took care of here, I accepted a diff for H1:IMC-REFL_SERVO_IN1GAIN (setpoint -2.00, epics -1.00) in order to proceed to Observing. I (actually T.Vo did, since he was already logged onto another workstation) also switched the omcparams.py starting voltage back to -24, which worked to get past the same problem described by Corey here. Note: I did NOT commit the change in omcparams.py to the SVN.
Were you able to get Input Align to work? Or did you try Kiwamu's workaround? (Just wanting to get data points on how Input Align step of Initial Alignment is going.).
svn up at .../SusSVN/sus/trunk/QUAD/Common/MatlabTools/QuadModel_Production
All current model features are summarized in a table in G1401132.
The main change in existing features is that the top mass damping now sees both the suspension and the cage, as in real life because we use OSEMs. Consequently, if you input seismic noise to a damped suspension it will enter both mechanically as usual, as well as through the damping loops. See Seismic_Noise_Propagation_2016_01_01.pdf. Page 1 shows longitudinal transfer functions from seismic noise to the test mass with and without the OSEMs seeing the cage. The second page shows the ratio of these transfer functions. Note that the ratio is greater than a factor of 2 at 4.5 Hz. Beyond 10 Hz the maximum is about 20% at about 10.5 Hz.
1. Additional inputs and outputs added to reflect the relative nature of the OSEMs - i.e. they measure relative displacements and actuate between two points
2. Suspension point reaction forces
The discussion above is one consequence of the first new feature. Another is that you can now make transfer functions between seismic noise and the top mass OSEMs, which is dramatically different from the seismic noise to top mass transfer function. See Seismic_to_Top_OSEMs_2016_01_01-2.pdf. These are obtainable in the model with the new 'toposem' field in the 'out' structure given by the generate_QUAD_Model_Production function.
The second new feature is that there are now outputs for the suspension point reaction forces on the ISI. These are obtainable in the model with the new 'suspoint' field in the 'out' structure given by the generate_QUAD_Model_Production function. These reaction forces allow us to dynamically couple the quad model to the ISI model. Thus, if we wanted, we can make one big ISI-SUS model.
This update includes significant under-the-hood modifications to how the pieces of the model are put together. Essentially, Simulink files now define the connections and signal flow, where previously this was all done with append/connect commands in the generate script. The motivation for this change is to make the model more extensible and maintanable by humans. The append/connect commands had become virtually unreadable with the dozens of inputs and outputs now in the model. Now someone can look at a more intuitive graphical representation in a simulink file to read or modify how the model is layed out.
There are 4 simulink files defining the 4 possible layouts of the quad model:
rev 7359: now reads foton files for main chain and reaction damping
rev 7436: Changed hard coded DAMP gains to get the correct values for LHO ETMX specifically.
rev 7508: Restored damping filter choice for P to level 2.1 filters as opposed to Keita's modification. Cleaned up error checking code on foton filter files, and allowed handling of filter archive files and files with the full path.
rev 7639: renaming lho etmy parameter file
rev 7642: Adding custom parameter file for each quad. Each one is a copy of h1etmy at this point, since that one has the most available data.
rev 7646: added ability to read live filters from sites, and ability to load custom parameter files for each suspension
rev 7652: updated to allow damping filters from sites from a specific gps time (in addition to the live reading option)
planned future revision - seismic noise will progate through the damping filters as in real life. i.e the OSEMs are relative sensors and measure the displacement between the cage and the suspension.
rev 7920: big update - added sus point reaction forces, top OSEMs act between cage and sus, replaced append/connect command with simulink files
no recent (at least 4 years) functional changes have been made to this file.
- rev 2731: name of file changed to quadopt_fiber.m, removing the date to avoid confusion with Mark Barton's Mathametica files.
- rev 6374: updated based on H1ETM fit in 10089.
- rev 7392: updated pend.ln to provide as-built CM heights according to T1500046
- rev 7912: the update described in this log, where the solidworks values for the inertias of the test mass and pum were put into the model, and the model was then refit. Same as h1etmy.m.
- rev 7640: created the H1ETMY parameter file based on the fit discussed in 10089.
- rev 7911: the update described in this log, where the solidworks values for the inertias of the test mass and pum were put into the model, and the model was then refit. Same as quadopt_fiber.m.
The quad model was tagged on the SVN both before and after this update. The tagged models are at
before this update: /ligo/svncommon/SusSVN/sus/trunk/Common/SusModelTags/Matlab/quadmodelproduction-rev7652_ssmake4pv2eMB5f_fiber-rev3601_fiber-rev7913_released-2016-01-01.mat This version reflects the model after the previous recent update discussed in log 24456, which updated the test mass and PUM inertias with solidworks values. No model features were changed in this update. After this update /ligo/svncommon/SusSVN/sus/trunk/Common/SusModelTags/Matlab/quadmodelproduction-rev7920_ssmake4pv2eMB5f_fiber-rev3601_fiber-rev7913_released-2016-01-01.mat
The tags were created using the following script:
/ligo/svncommon/SusSVN/sus/trunk/Common/MatlabTools/tagsusdynamicalmodel.m rev 7923
Just as an FYI, I have done this svn update.
MInor updates and fixes:
1) The simulink files were generating warnings in Matlab 2012b because they were saved in 2013a. I resaved them in 2012b, recommited, and the problem has gone away. Matlab versions 2013a and 2015b are fine as well. No promises for versions earlier than 2012b.
2) While fixing the simulink diagrams, I added some extra inputs based on a disucssion with Brian Lantz. These are 'osem like' force inputs acting between the top mass and the cage for the purpose of testing the reaction force outputs on the ISI. These will not impact any prior features of the model.