Replaced the 1A fuses for CP7 and CP8 with a 2.5A.
1/2 open LLCV bypass valve, and the exhaust bypass valve fully open.
Flow was noted after 66 seconds, closed LLCV valve, and 3 minutes later the exhaust bypass valve was closed.
Made measurements of the oscillator power noise with a few photodiodes. PowerNoise.png shows the free-running oscillator relative power noise measured before the acousto-optic modulator. This is more than 10 times noisier than when the laser was installed in the H1 enclosure. The other trace in the plot is the out of loop of the relative power noise. It is also about a factor of 10 higher than it should be. Whilst the power stabilisation was locked, I looked at the AC coupled output of the photodiode and did not observe any oscillations. The maximum peak-to-peak variations were ~40 mVpp.
If I am reading this plot correctly, the ~37kHz rep-rate seen in last week is probably represented in this spectrum by the peak which the ISS is adding at that frequency. (The 500kHz oscillation is too high to see here.) It might be very informative to see what is going on above 100kHz since the ISS seems to be adding a lot of noise at 100kHz (about a factor of 10 above its input).
Is this plot really calibrated into RIN?
The digital RIN readback for the OOL inner-loop sensor appears to be 20 dB lower than the trace shown here (26773). Same for the digital readback for the HPO transmission.
Look at alog 26893.
Peter's "relative power noise" agrees well with the raw voltage spectrum of Rick and mine. In other words, Peter's plot seems to overestimate RIN by 15 dB or so for the HPL monitor (DC level is about -6V), and about 20dB for 1st loop sensor (DC level -9 to -10 Volt).
The X1 PT140 Pirani gauge is reading above the software interlock threshold to turn on the Cold Cathode gauge. Per Chandra's request I have bypassed the software interlock by forcing the variables in Beckhoff on h0velx (see attached screenshot).
We may use the intermittent "bad" behavior of the pirani/cable/connection or whatever as an excuse to install the aLIGO wide range gauge sooner rather than later.
Added 3194 channels. Removed 592 channels. (See attached channel list)
J. Kissel, S. Dwyer As identified yesterday (LHO aLOG 26793), we've needed to *re*flip the ESD bias sign in order to resume bringing the accumulated charge on the test masses back down to zero. As such, we have reverted the requested bias voltage to what had been done in February (see LHO aLOG 25575) and performed all of the necessary changes in settings that are ancillary to the change. Note, there are a few changes / additions in what needs changing from Kiwamu's February flip, so I'll re-list everything here: [Bias Flip on ETMX] - Changed H1:SUS-ETMX_L3_LOCK_INBIAS from -9.5 to +9.5 [V_DAC] - (unlike before) The ISC_LOCK guardian (now) takes care of checking the sign of H1:SUS-ETMX_L3_LOCK_INBIAS, and adjusting the sign of - H1:SUS-ETMX_L3_DRIVEALIGN_L2L_GAIN from +1.000 to -1.000 (fixes the ESD stage longitudinal loop gain to match the bias sign change) - H1:SUS-ETMX_L3_DRIVEALIGN_L2P_GAIN from +0.021 to -0.021 (fixes the F2P sign) - H1:SUS-ETMX_L3_DRIVEALIGN_L2Y_GAIN from +0.007 to -0.007(fixes the F2P sign) - H1:SUS-ETMX_L3_ESDOUTF_LIN_FORCE_COEFF from -124518.4 to +124518.4 (fixes the linearization force coefficient to match the new bias sign) accordingly. (Note that it's marked as a #FIXME, but these values are hard-coded into the guardian) - (unlike before) Accepted the new values in *all* SDF snap files, /opt/rtcds/userapps/release/sus/h1/burtfiles/ - h1susetmx_down.snap - h1susetmx_safe.snap by loading in each table and accepting the values I've changed, followed by a commit to the userapps repo. - This also involved *creating* a copy of the down.snap in the userapps repo, and changing the file in the target/h1susetmx/h1susetmxepics/burt/ directory to a soft link, as was already the case for the OBSERVE.snap and safe.snap) - All the changes in settings had been accepted on the OBSERVE snap on the Feb flip, so I didn't need to accept any new values) - (like before) There's no need to make any further changes in the CAL-CS epics settings, because ETMX is not used in any capacity for calibration. [Bias Flip on ETMY] - Changed H1:SUS-ETMY_L3_LOCK_INBIAS from +5.0 to -9.5 [V_DAC] - (like before) The ISC_LOCK guardian takes care of checking the sign of H1:SUS-ETMY_L3_LOCK_INBIAS, and adjusting the sign of - H1:SUS-ETMY_L3_DRIVEALIGN_L2L_GAIN from +30.0 to -30.0 - Note that previously, this check had been in the ISC_LOCK state of just before "NOMINAL LOW NOISE" which seemed too late, so we moved this check into the DOWN state just under where it's checked for ETMX. - (like before) there are no off-diagonal L3 DRIVEALIGN coefficients in use (and L2P / L2Y or P2L / Y2L), but if they were, we would have needed to flip those signs too. - (unlike before), I've by-hand changed the linearization force coefficient sign, - H1:SUS-ETMX_L3_ESDOUTF_LIN_FORCE_COEFF from +124518.4 to -124518.4 Even though linearization is not used in nominal low-noise (not even during charging measurements), I think it's important to be consistent during these flips lest it bite us later if someone wishes to turn on the linearization. - (unlike before) Accepted the new values in *all* SDF snap files, /opt/rtcds/userapps/release/sus/h1/burtfiles/ - h1susetmy_down.snap - h1susetmy_observe.snap - h1susetmy_safe.snap by loading in each table and accepting the values I've changed, followed by a commit to the userapps repo. (This also involved *creating* a copy of the down.snap in the userapps repo, and changing the file in the target/h1susetmy/h1susetmyepics/burt/ directory to a soft link, as was already the case for the OBSERVE.snap and safe.snap) [Making sure Calibration is unaffected] - (like before) We must make sure that the CAL-CS replica of the ETMY actuation matches the SUS ETMY digital signal chain. However, because the CAL-CS model had not been restarted, and its SDF system had been kept up-to-date it did not lose the appropriate settings, so the settings for - H1:CAL-CS_DARM_FE_ETMY_L3_DRIVEALIGN_L2L_GAIN remained -30.0 - H1:CAL-CS_DARM_ANALOG_ETMY_L3_GAIN remained +1.0 - (unlike before) Again, to be consistent, I've changed the sign of the linearization force coefficient, - H1:CAL-CS_DARM_FE_ETMY_L3_ESDOUTF_LIN_FORCE_COEFF from +124518.4 to -124518.4 - (unlike before) Accepted the new values in *all* SDF snap files, /opt/rtcds/userapps/release/sus/h1/burtfiles/ - h1susetmx_observe.snap - h1susetmx_safe.snap by loading in each table and accepting the values I've changed, followed by a commit to the userapps repo. (Since there is no change between the "down" and "observation" state, a "down" .snap doesn't and need not exist.) Back in the day, Joe Betz had the idea of writing some guardian code that would keep the CAL-CS model up-to-date with the SUS model's digital settings. That would make this last step unnecessary. I'll ask what the status is on that. It still good to check all of these things anyways, though. I attach a bunch of screenshots which should what I've accepted in each SDF file for future reference. Sadly, because we've not locked the IFO on ETMY for quite some time, we cannot check the DARM open loop gain to confirm that all is well with the calibration. Further, the actuation strength will have likely changed and we're going to remeasure it anyways prior to ER9, so there's little point in double checking the actuation strength. So there's no further things to do this time around. However, if and when we do have a viable calibration, I'll remind you of the steps, which are at the bottom of LHO aLOG 22135.
Per https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=26806 CP5 LL has stabilized to its normal conditions. Still has a jittery output.
Lots of lock losses and FSS oscillations. Sheila and Jenne investigating. 14:15 UTC Chris S. working in LVEA moving barrels from bottom of stairs into the high bay 14:30 UTC Jeff B. to HAM6 and PSL rack 15:00 UTC Chris S. done in LVEA, working in high bay until 17:00 15:17 UTC Kyle to LVEA 15:17 UTC Peter to H1 PSL enclosure 15:28 UTC Jeff B. back 16:24 UTC Filiberto to LVEA to terminate cables for PT170 and PT180 BPG402 gauges 16:54 UTC Kyle back from climbing on HAM11, HAM12, BSC4 17:05 UTC Jamie restarting h1guardian0 for code upgrade 17:12 UTC Christina and Karen to mid Y Peter done 18:20 UTC Turned on and off PSL noise eater in PSL rack 18:21 UTC Christina and Karen done at mid Y 18:33 UTC Jeff B. to LVEA to check dust monitor cabling 18:56 UTC Dave restarting OMCPI, SUSPI models, DAQ restart 18:58 UTC Jeff K. changing SUS ESD bias 19:19 UTC Filiberto out for lunch 19:21 UTC Jeff B. out of LVEA 19:26 UTC Sheila to LVEA to investigate FSS oscillations 19:39 UTC Filiberto to LVEA to continue cable work 19:53 UTC Gerardo to end Y to replace electric LLCV motor fuse 19:55 UTC Sheila back, made no changes 20:11 UTC Gerardo changed CP7 electric LLCV motor fuse, going to mid Y to overfill CP3, then end X 20:17 UTC Joe to LVEA to track down view port equipment 20:19 UTC Jeff B. to turn on dust monitor at PSL 20:48 UTC Gerardo changed CP8 electric LLCV motor fuse 20:48 UTC Filiberto done 21:00 UTC Jeff B. done 21:47 UTC Gerardo to BSC4 to look at PT140 cabling 22:20 UTC Gerardo back 23:03 UTC Gerardo to LVEA to measure PT140 voltage at vacuum rack
This upgrade includes a couple of minor bug fixes and a new guardian log server/client:
After these changes were applied, all nodes were re-created to get the new changes to the logging, and the h1guardian0 machine was rebooted. A couple of small issues were encountered during the reboot:
This version of guardian includes a new and improved log client/server. The new server running on the h1guardian0 machine:
See "guardlog -h" for more info.
Tega, Ross, Dave WP5850
We added two Dolphin IPC senders on the h1omcpi model (running at 64kHz) and two corresponding receivers on h1susitmpi. These send the OMC DC_PD signals for A and B PDs. A new common part in PI_MASTER.mdl was created.
Both models were restarted, followed by a DAQ restart.
model restarts logged for Tue 26/Apr/2016 DAQ restart for Vacuum LX and LY upgrade to Beckhoff. h1fw1 instability.
2016_04_26 01:24 h1fw1
2016_04_26 03:13 h1fw1
2016_04_26 11:05 h1dc0
2016_04_26 11:05 h1nds0
2016_04_26 11:05 h1nds1
2016_04_26 11:06 h1fw1
2016_04_26 11:07 h1broadcast0
2016_04_26 11:07 h1fw0
2016_04_26 11:07 h1tw1
2016_04_26 20:34 h1fw1
model restarts logged for Mon 25/Apr/2016 DAQ restart for vacuum MY upgrade to Beckhoff. ASC and ETMXPI model changes (with DAQ restart). both FW instability.
2016_04_25 01:04 h1fw1
2016_04_25 05:53 h1fw1
2016_04_25 06:23 h1fw1
2016_04_25 08:34 h1fw1
2016_04_25 08:54 h1nds1
2016_04_25 09:23 h1fw1
2016_04_25 12:08 h1broadcast0
2016_04_25 12:08 h1dc0
2016_04_25 12:08 h1fw0
2016_04_25 12:08 h1fw1
2016_04_25 12:08 h1nds0
2016_04_25 12:08 h1nds1
2016_04_25 12:08 h1tw1
2016_04_25 13:03 h1fw0
2016_04_25 13:20 h1asc
2016_04_25 13:27 h1susetmxpi
2016_04_25 13:30 h1broadcast0
2016_04_25 13:30 h1dc0
2016_04_25 13:30 h1fw0
2016_04_25 13:30 h1fw1
2016_04_25 13:30 h1nds0
2016_04_25 13:30 h1nds1
2016_04_25 13:30 h1tw1
2016_04_25 20:33 h1fw1
2016_04_25 21:03 h1fw1
2016_04_25 21:05 h1fw0
2016_04_25 22:23 h1fw1
model restarts logged for Sun 24/Apr/2016 No restarts reported
model restarts logged for Sat 23/Apr/2016 No restarts reported
model restarts logged for Fri 22/Apr/2016 No restarts reported
model restarts logged for Thu 21/Apr/2016 FW0 instability. ETMXPI model change (no DAQ restart required)
2016_04_21 01:17 h1fw0
2016_04_21 01:25 h1fw0
2016_04_21 16:52 h1susetmxpi
After the chiller problems noted in the LLO aLOG #25879, I did a visual inspection of both the LHO chillers. There was no evidence of damage or deformation to the compressor or the crossbar. The coolant reservoir is not leaking. When the chiller is shut off there is a big back surge of water, which has enough force to blow the filler plug across the room. If the filler plug is screwed in too tightly and there is no other pressure relief in the coolant system, it is possible the rapid pressure increase due to the water surging back into the reservoir could burst a seam in the reservoir. We leave our filler plug loosely secured so as to act like a pressure relief valve.
PEM: All new dust monitors installed except in PSL enclosure. VAC: Replacement of fuse for CP1 electric fill valve. Investigate failure of BSC4 Pirani gauge. Investigate fill control of CP5.
Phil is replacing the fuse at CP1 with one larger than 1 A since the new electronic valves draw at least that much current. CP1 has overfilled as a result. Current fill level at 5%.
DIAG_MAIN notification shows that HWSX had bad peak counts for a moment. Timeseries shows that this happened between 4:10 and 4:13 UTC but got better on its own. The glitches is probably caused by me stopping and restarting the code to look at stream images. They look fine. The output power off HWSX sled is ~0.8W.
I think you mean 0.8mW
Oops yes. Sorry.
Chris, Keita, Evan
Today we were able to lock the outer ISS loop with the modecleaner at 20 W (and no interferometer). We looked at several PSL/IOO PD signals (the FSS transmission PD, the ISS inner-loop PDs, the IM4 transmission PD, and the ISS outer-loop PDs) and tried to understand their behavior in different ISS configurations.
Naively one would expect all these signals (except the in-loop ISS PDs) to agree with each other, since they should all be out-of-loop sensors for the RIN leaving the PMC. Together, these signals monitor three of the four PMC ports: the FSS transmission sees the RIN of one port, the out-of-loop inner-loop ISS PD sees the RIN of another port, and IM4 trans and the out-of-loop outer-loop ISS PD sees the RIN of yet another port.
These are the behaviors we observed (see attached pdf):
We think that a possible explanation for these effects is that both ISS PDs are seeing some correlated noise that is not seen by either the FSS PD or the post-IMC PDs. In this scenario, the inner-loop ISS would suppress the HPO noise but impress this correlated noise on the light entering the PMC.
Briefly we entertained the idea that the light circulating in the PMC could be multimoded (either from the NPRO or the HPO), but judging from the RIN before and after the IMC, this seems to not be the case (png attachment).
One other idea is that some of the 808 nm light is getting through the PMC and onto the ISS.
Is this really incompatible with jitter? There are a lot of variations visible on the PMC reflected camera. The finesse of the PMC isn't that great (~100), and neither is jitter supression. If there is a static misalignment into the PMC, there would also be a linear term for the jitter to intensity conversion. The two inner loop detectors see rather different signals at 10Hz, if the inner loop is engaged but not the outer one.
Certainly the jitter seen on the IMC WFS is worse than before the HPO turn-on.
Before the turn-on, the jitter below 100 Hz was 1 nrad/Hz1/2 or so (LHO#21212). Now it is 10 nrad/Hz1/2 at 10 Hz, with a 1/f slope.
The attachment shows IMC signals with the inner ISS loop off (dashed) and on (solid).
Update: BS alert. Read the next entry.
Jitter is much larger than before, but the jitter alone doesn't seem to explain all of our observations at the same time when the 1st loop is closed but the 2nd loop open.
PDA=P+a*J+Sa, PDB=P+b*J+Sb, IM4=P+x*c*J+Sim4
P is the intensity noise leaving the AOM. When the loop is open it's just the free running noise P0.
J is the beam jitter (01 amplitude relative to 00) coming out of PMC.
a, b and c are the jitter to intensity coupling at PDA, PDB and IM4 trans due to clipping or diode inhomogeneity or whatever.
x is the attenuation of 01 mode amplitude by IMC, which is about 0.3%.
Sa, Sb and Sim4 are the sensing noise.
When 1st loop is closed, J is imprinted on P:
P=P0/(1+G) - G/(1+G) *(b*J + Sb) ~ P0/G - b*J - Sb,
PDA ~ P0/G + (a-b)*J +Sa-Sb,
IM4 ~ P0/G + (x*c-b)*J + Sim4-Sb ~ P0/G -b*J +Sim4-Sb. (note x=3E-3.)
where G is the OLTF.
Allowing some conspiracies but not extreme ones, lack of coherence between PDA and IM4 is explained in either of the following:
The first case is false because swapping PDA and PDB makes no difference in IM4.
In the second case, PDA spectrum should look like all sensing noise, but this "sensing" noise in reality is big at 10Hz.
So, even if the clipping effect is common in PDA and PDB so the PDA and IM4 becomes incoherent, we need another noise that is not unlike big sensing noise, i.e. of about the same amplitude on PDA and PDB, is incoherent between PDA and PDB, and does not appear on downstream sensors.
I take my words back about PDA-downstream coherence.
I was looking at the coherences from this morning, and it seems like when only the first loop is on, 1st loop out of loop sensor is coherent with downstream sensor before and after the IMC (attached, bottom red and blue). The plot is calibrated in RIN.
Note that we switched the control photodiode from PDB to PDA last night, so in this plot the out of loop sensor is PDB. I switched them back again at 17:49:10 UTC.
Anyway, out of loop sensor is more coherent with downstream sensors than HPL monitor is at f<10Hz (bottom red|blue VS brown|pink), but HPL is more coherent from 10 to 200 Hz. Difference between bottom brown and bottom pink probably doesn't mean much, just the noise floor difference between IMC-PWR and MC2_TRANS.
Some thinking necessary, but at the moment I cannot say that jitter cannot explain everything.
John and I visited CP5 before lunch today to investigate why the liquid level is so noisy (compared to CP6). We verified wires were tight at the controls rack, and eventually made our way to the LL transducer. We closed the exhaust at transducer and the flow stabilized suggesting the instability is caused by a real pressure differential and not electric. We did not check the LLCV pneumatic actuator. After trending the numbers this evening, looks like we did a real number on the system. See plots attached. The % valve open is ranging full scale and LL full spans 90-95%.
Could this be related to the midstation air compressor replacement?
Richard just reset the PID values (same values). The LL seems to have stabilized (well, to its prior stability which is still relatively noisy). We will watch it throughout the day.
C. Cahillane I have produced statistical uncertainty spectrograms for all of O1. For the most part the uncertainty doesn't change much over all of O1. The biggest concern is a couple days around Nov 17th with large kappa variations. Again, Jeff has suggested that I detrend all of the kappas to eliminate this spike in uncertainty. I believe that this is good evidence that the statistical uncertainty over all of O1 is fairly constant. For the LLO statistical uncertainty spectrograms, please see LLO aLOG 25652.
C. Cahillane I have detrended the kappas and reproduced the above spectrograms without the massive spikes of uncertainty.
Michael, Hugh, Krishna
A lot of progress was made with the installation of BRS-2 today. In the morning, we cleared out a space on the VEA floor. We had to slightly reposition the SEI ground seismometer (STS2) and the PEM Guralp seismometer. We then cleaned the BRS-2 vacuum can, foam box and other parts and moved them in. Upon opening the vacuum can, we noticed that the epoxy (TorrSeal) on one of the capacitor plates had come off, likely during the drive. We found a suitable alternative (Loctite 1c) and reattached the capacitor plate.
We the proceeded with the assembly. The beam-balance was pulled out, the flexures were carefully attached and the beam-balance was then reinserted into the can and suspended from the flexures. We did a crude adjustment of the horizontal center of mass. The vacuum can was then partially closed up and the autocollimator attached to it. We then had to realign the optics to get the reflections from the reference mirror and the main mirror algined well. Tomorrow we will continue with autocollimator adjustments to get good reflection patterns on the CCD.
In the meantime, Jim B and Carlos installed the BRS-2 Beckhoff computer at End Y. Also, Filiberto and Peter laid out the GiGE, Ethercat and Fiber-Optic (For the autocollimator light source) cables going from the VEA to the computer room.
Plan for tomorrow:
1. Get the C# code to read the CCD data and start measuring the tilt signal. At this point, the instrument is still in air, so will have excess noise and drifts.
2. Hook up the electronics for the capacitive control and the DACs for writing out the signals. Once the cables to go from these to the SEI Frontends is complete, the tilt data will be accessible to SEI.
3. Close up the rest of the vacuum can.
I attach a collection of pictures I took during this day's installation. I was primarily focused on pictures of the electronics readout system that's new for BRS 2.0, but there are also some pictures of the balance and vacuum can. Let me know if you like and need any of the originals. For my record, the originals live on my laptop, in the folder /Users/kissel/Desktop/scratch/2016-03-24/