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.

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).

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

Guardian has been upgraded to r1519, and the h1guardian0 machine has been rebooted.

This upgrade includes a couple of minor bug fixes and a new guardian log server/client:

• Guardian nternal channel access server updates at same rate as the main process thread.  This should address the state not registered bug.
• Minor fixes, improvements, and tweaks to some of guardutil functions
  • fixed 'git-clone' function to retrieve the archive
  • improved the 'plot' function to plot node status info around a specified time
  • added 'state-hist' function to print guardian states over a specified time range
• new guardlog client/server
• changes to node logging on h1guardian0 to increase log size, and compress logs on rotation.  This requires the new log server for searching the logs

h1guardian0 reboot

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:

• Some of the manager nodes thought that they had requested states from their subordinates, but the subordinates where in the NONE state (no request).  My guess is that this might be due to some sort of race condition as the nodes are initialized (cas is initialized before the nodes starts processing requests?).   This happened with some of the SEI nodes and the ISC_LOCK.  It was trivially resolved by requesting INIT from the managers.
• BRS nodes have no initial request defined, so they can up with NONE requests.
• SEI_BS is managed by ISC_LOCK, but ISC_LOCK is not initially doing anything.  At some point during initialization SEI_BS stalled, so it just sat there stalled.  Not a big deal, but could maybe be handled cleaner.

New guardctrl log client/server

This version of guardian includes a new and improved log client/server.  The new server running on the h1guardian0 machine:

• has a new RESTful http interface
• is now able to process the now possibly compressed node logs
• handles queries with date range filters, filtering for log files and log lines within the files that correspond to the date/time search parameters
• output log lines with timestamps in UTC, local, or GPS time

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.

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):

• When neither ISS loop is closed, both the FSS and IM4 transmission PDs see the noise of the HPO (about 1×10⁻³/Hz^1/2 at 10 Hz). From 10 to 100 Hz, these PDs are coherent with each other and with the HPO PD. All four of the ISS PDs are swinging rail-to-rail in this configuration, so they are not useful. [Apricot traces.]
• When the inner ISS loop is closed, the FSS PD, IM4 PD, and outer-loop ISS PDs see a RIN that is a few times 10⁻⁵/Hz^1/2 at 10 Hz, with a 1/f slope. These three signals are coherent with each other between 10 and 100 Hz. However, the inner-loop PDs are in some parallel universe in which the inner-loop appears to be happily stabilizing the laser RIN to better than 10⁻⁶/Hz^1/2 at 10 Hz. The inner-loop PD signals have low coherence with the FSS, IM4, or outer-loop PDs between 10 and 100 Hz. [Red and blue traces.]
• When the inner and outer ISS loops are closed, the outer-loop PDs seem to behave sensibly. The out-of-loop RIN is slightly better than 10⁻⁷/Hz^1/2 at 10 Hz. The IM4 PD more or less agrees. However, the FSS RIN seems to show no change from the previous measurement (inner ISS loop only), and no longer has very much coherence with the IM4 and outer-loop PDs. The FSS has some coherence above 100 Hz with the outer-loop PDs. The inner-loop PDs now see the 1/f RIN of the FSS PD, and they are coherent with this PD. [Purple and green traces.]

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.

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%.  

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.

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.