Sheila Jenne Matt Carl Jeff

Tonight we tried a repeat of what Kiwamu and I did last week, and we were able to restore a recycling gain of ~32 (according to the POP DC/ IM4 channel, which is more like 36 according to the way we calculated it durring O1) at 40 Watts.  We moved PRM PIT 90 urad in the negative direction, and had to touch up SRM as we did that.  We moved the spot on the POPX WFS enough that we railed the PZT and the spot was off center by 0.5.  Again the spot on POP A was mostly on just the bottom 2 quadrants.   The power on the baffle PDs also decreased as we moved the alingment.  We also tried Yaw but this wasn't able to improve the recycling gain.

Since it seems like we might want to use pico motors on POPA, Jenne tried to repeat the PRM move at 2 Watts by moving PRM to match the witness sensors at 40 Watts, she could only go about half way before we lost lock. 

[Matt, Carl, Jenny, Sheila, Evan, Jeff]

The SR785 monitorring the ETMY QPD transmission has not uncovered any large hidden test mass accoustic modes in the 65-75kHz band.  It has however highlighted the fact that there is a strange 3kHz comb on these QPDs.  See this first image showing the comb (3 peaks) and the second image showing the 65-75kHz band at 50W.

This comb is present on both the fast 10-80kHz PI channels and the normal QPD A channel.  The comb appears in the X and Y arm but they are not identical.  See third image.  Also in this image the spectra before and after the whitening gain is changed (in guradian state DRMI_ON_POP) indicates that the source of these peaks lies before the whitening gain stage.

There is little indication of anything in OMC DCPDs other than these peaks being in the vicinity of violin mode harmonics - see last image.

We lost the changes to the ASC model that we made before to add POP90 to ADS.  I added it again, and did a make but not a make install.  Hopefully we can do this tomorow, if needed after the timing system work, so that we can make a dither loop for SRM.  This is svn version 13780

I restored all the HEPI safe.snap files for SDF review.  HAM1 sensor correction was the only settings needing accepting.

For the BSC ISIs, I accepted all the blend filter changes--these arose from Jim's filter bank cleanup.  The resolution for all the other diffs between the OBSERVE state and the safe.snap file are captured on the attached snapshots of the SDF diff screen before they were confirmed.

I'll do the HAM ISI in the morning.

Over-filled CP3 with the exhaust bypass valve fully open and the LLCV bypass valve 1/2 turn open.

Flow was noted after 141 seconds, closed LLCV valve, and 3 minutes later the exhaust bypass valve was closed.

AT 21:11 ITMX bias was ramped to 9.5V DAC output over ten seconds and at 21:12 ITMY bias was ramped on over ten seconds.  The interferometers was in DC_READOUT_TRANSITION with 2W.  There was no apparent disturbance.
These setting have been incorperated into the SUS_PI guardian such when it enters QPD_PI_DAMPING the bias is ramped on.  This currently happens in the ISC_LOCK guardians DC_READOUT state.  The bias is ramped to zero when entering the IFO_DOWN state.

J. Kissel, J. Driggers, B. Weaver, E. Merilh. E. Hall, H. Radkins, D. Sigg

In prep for the timing system software update, which'll need all front-ends to be turned off and restarted tomorrow, we've reconciled the SDF system in the ISC_LOCK guardian's "DOWN" state (note that in this state, some front ends are using the "safe" some are using "down" and some are using "OBSERVE" snap files). 

Notable things that we accepted:
- Bounce and Roll monitoring FMs (H1:OAF-BOUNCE_[ETMX, ETMY, ITMY, ITMX]) were found to have FM3 (a broad band-pass) in place instead of FM4 (a narrow band-pass). We reverted to have FM4 ON and FM3 OFF.
- PCAL Y 1083.7 Hz line has been off since June 28. We couldn't find an aLOG, but I recall we turned the 1 kHz line off to preserve range on the PCAL. We've accepted that it's off.
- The Beam Splitter M2 stage LOCK_P and LOCK_Y has bounce and roll mode notching filters for both the BS's bounce and roll modes at 17.7 & 25.7 Hz (FM5 "BounceRoll"), as well as for the QUADs at 9.63 and 13.4 Hz (FM7 "EvanBR"). We found that FM7 was OFF since Jun 28th, and we think we want it ON, so that MICH isn't affected by the ITM bounce and roll modes when actuated in Pitch and Yaw.
- We found the IMC Master WFS gain at 0.09 instead of 0.1, and has been so since July 13th. Seems silly, so we reverted to the gain of 0.1.
- The newish Daniel-style integrators for POP X WFS DC centering servo were found with there bleed-off engaged (via H1:ASC-POP_X_PZT_PIT/YAW_BLEEDEN), as desired since Jun 28. We accepted the bleed off ads engaged it. 
- The INP1 Yaw offset was previously -800, and is now 0.0. We accepted the 0.0, because this offset was used to PRC gain spelunking, and is now no longer in favor.

After we went through one round of clearing out, accepting, and reverting, we got mid-way through the lock acquisition sequence and lost lock back to the DOWN state again. For any further channels and changes that occurred, (especially on the suspensions), I UN-monitored those channels. 

I looked at the HEPI tidal offloading signals from one of Friday's locks to try to extract the power circulating in the arms.

As the interferometer powed up from 2 W to 40 W, the offloading signals compensated for 4.3(3) µm of radiation-induced displacement. This amounts to 130(14) kW of power circulating in each arm for 40 W of PSL power. The uncertainty comes from (1) the difference between the X and Y offloading signals, (2) nonlinear drift in the earth tides (only the linear component has been subtracted here), and (3) an assumed 10% uncertainty in the displacement calibration.

On the other hand, if we believe that there was 95(10) kW of power in each arm given 22.5 W of PSL power, we would expect 169(18) kW of power in each arm at 40 W, assuming no power-dependent arm loss. The discrepancy between the expectation and the observation amounts to 30(20)% missing power. This is consistent with previous estimates of the recycling gain loss during power-up.

This constraint could be improved by (1) making the PSL power increase faster, so that the earth tide behavior can be better constrained, and (2) turning off the HEPI offloading and instead watching the UIM offloading.

• Nothing much to report from sub-systems.
• There was some discussion of the Timing System work that will be done on Tues.
• PSL report was touched on. https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=28466
• Work Permits were gone through.

As I happened to be debugging one of my MEDM user screens I noticed that there was some odd behaviour with the
FSS.  It wasn't going out of lock or oscillating but the PZT voltage exhibited some small discrete jumps.  Then
I noticed that it was perhaps due to the ISS acquiring and breaking lock.

    Attached is a plot of the last hour's data.  There's a gap in the data stream starting from about 06:40
and lasting about 13 minutes.  The AOM drive should hover somewhere between 0.500 and 0.550.  This is a better
indicator of how things are (at the moment) rather than the % diffracted power, as this is close to where the
response is linear.  Lower than this value and the response is somewhat parabolic.

Richard called saying the laser was off when he entered the Control Room this morning.

    According to the laser status screen, the laser tripped due to a crystal chiller flow rate
error, somewhere in the power meter circuit.  Attached are two plots of the previous one day's
trend data.

    The signal from head 2 is somewhat noisier than the signals for the 3 other heads.  Looking
back even further it seems to have been that way for at least the 6 days.  Unfortunately we do
not have enough diagnostics to pinpoint the location of the potential blockage and at this point
in time it is a bit of a waiting game unless time is scheduled for invasive maintenance.

    After restarting the laser at ~06:30, things seem to have settled down by 06:40.

I set up a magnetometer at EY near the ESD chassis in the VEA for a blip glitch study (see upcoming log from Paul). The plot shows the channel names (12 and 13 are the Y and Z axes) and very high coherence between the mag and DARM at odd harmonics of 1 Hz. This is one of the new combs that Ansel identified and so this channel may also be useful in seeing if it goes away during the reboots on Tuesday.

Carl, Evans, Stefan,

We had h1ecatx1 crash. A reboot didn't bring back the connection - we had to log in and manually start start.bat.

Then we ran into strange guardian behaviour, which was tracked down to epics channels having different values on h1guardian0 and operator machines.

In particular, on h1guardian0:

In [8]: ezca['ALS-Y_LOCK_ERROR_FLAG']
Out[8]: 1
 

while on operator 0 I get:

In [7]: ezca['ALS-Y_LOCK_ERROR_FLAG']
Out[7]: 0

 

The wind direction part of the anemometers still seems to not be reading correctly.
There was some discussion on the SEI call today that maybe it had started working, but a look at the DetChar page at
https://ldas-jobs.ligo-wa.caltech.edu/~detchar/summary/day/20160714/pem/wind/
shows good info for wind speed, but nothing sensible for wind direction.

I put some data into the SEI log about wind direction as seen at the Tri-cities airport. 
https://alog.ligo-la.caltech.edu/SEI/index.php?callRep=1035
The FAA and Jim agree that strong winds come from the southwest.