The operator reported issues with the remote access control system.  It was repeatedly asking for his credentials.  I was able to walk him through adding a user to the system so that he could get some help brining with the IFO.  I also was granted access.

I restarted the apache instance on cdsadminctrl after reproducing the operators issue.  This appears to have solved the issue. Apache was not able to negotiate the authentication.  Cause currently unknown.  I've opened an FRS to remind me to look at it in the morning.

See FRS https://services.ligo-la.caltech.edu/FRS/show_bug.cgi?id=7677

Violin modes seem very high on DARM spectrum so I had a quick look at the damping screens. It appears that many of the filter banks (especially ETMs) have 0 input and 0 output. I also checked with the fast channels and dtt. The input seems nonzero on dtt but the output has nothing. As the result, some of the violin modes are not being damped right now. Hope it stays through the night until somebody comes in and fix this tomorrow.

During maintenance I turned on the new op lev damping roll off filter.  (34954)  This means that oplev damping noise should be about a factor of 3 below the ASC noise (and the DARM noise) at 10 Hz.

Attached is a comparison of new/old open loop gain measurement made with no power in the arm, and the drive levels in low noise with the new filter engaged.  For a comparison to the drives with the old cut offs see 34735

We continue the study of 34863 to explore what effects can differential ITMs cause, as motivated by the high absorption point on ITMX reported in 34853 and 34900.

This time in addition to differential thermal lenses, we also added ITM losses into consideration. 

Some key messages from the simulations are: 

1. The carrier build-up in the PRC is sensitive to losses (apparently), but not to the differential lensing. The RF9 build-up is more sensitive to differential lensing effects than the carrier. 

2. The DARM cavity pole is NOT sensitive to ITM losses, but can be changed by differential lensing. See the first plot.

3. The SRM alignment signal is sensitive to differential lensing, but NOT to ITM losses. See the second plot.

=========================================================================

Some details: 

We start from the Finesse input file T1300904, but changed the ITMX and ITMY losses each to 75 ppm, so that the carrier gain in PRC is 40. We also reduced the DARM LSC locking point to account for the losses. The SRC gouy phase corresponding to that file is 20 deg.

We first computed the DARM transfer function (ETM diff phase -> field leaving from the AS port) for a set of extra ITMX lensing, while fixing ITMX loss = ITMY loss = 75ppm. The poles were recorded and fitted with a quadratic function. 

Then we fixed ITMY loss = 75 ppm but increase ITMX loss from 75 ppm to 95 ppm. We used two ITMX lensing setting, one with no extra ITMX lensing, one with extra 100 km lensing. For a given diff lensing setting, increase ITMX loss caused the carrier gain dropped from 40 to 36, as expected. At the same time the DARM cavity pole changed by no more than +- 1 Hz. On the other hand if we held loss fixed, changing ITMX lens had tiny effect on the carrier PR gain, but it affected the RF9 build up.

For SRM sensing, there was essentially no effects due to extra differential losses, as shown in the second plot for an extra ITMX lens of f=100 km, SRC gouy phase = 20 deg, and ITMX loss = 95 ppm (blue dashed) or 75 ppm (yellow dotted), and ITMY loss = 75 ppm. 

So a possible scenario suggested by the simulations so far might be: when the ifo was cold, we had okay PR gain and SRM sensing. As it being heated up, the high absorption point caused both more losses (which degraded the PR gain) and extra lens (which affected SRM sensing). According to the simulation, we might also expect some drop in DARM pole. Is this observed in reality? 

J. Kissel

I've gathered our "bi-weekly" calibration suite of measurements to track the sensing function, and ensure all calibration is within reasonable uncertainty and to have corroborating evidence for a time-dependent detuning spring frequency & Q. Trends of previous data have now confirmed time dependence -- see LHO aLOG 34967.

Evan is processing the data and will add this day's suite to the data collection.

We will begin analyzing the 7.93 Hz PCAL line that's been in place since the beginning of ER10, using a method outlined in T1700106, and check the time dependence in a much more continuous fashion. My suspicion is that the SRC detuning parameters will change on the same sort of time scale as the optical gain and cavity pole frequency.

Note also, that I've grabbed a much longer data set for the broad-band injection, as requested by Shivaraj -- from 22:50:15 UTC to 22:54:20 UTC, roughly 4 minutes.

The data have been saved and committed to:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/O2/H1/Measurements/SensingFunctionTFs
    2017-03-21_H1DARM_OLGTF_4to1200Hz_25min.xml
    2017-03-21_H1_PCAL2DARMTF_4to1200Hz_8min.xml

    2017-03-06_H1_PCAL2DARMTF_BB_5to1000Hz_0p25BW_250avgs_5min.xml
The data have been exported with similar names to the same location in the repo.

For time-tracking, this suite took ~38 minutes from 2017-03-21, 22:18 - 22:56 UTC.

 TITLE: 03/21 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC

STATE of H1: Observing at 68Mpc
INCOMING OPERATOR: Jeff
SHIFT SUMMARY: Maintenance day. Tumbleweeds blocked the Xarm so that filtered out some work. I had some issues locking with ALS_DIFF not fining IR and causing a lock loss. 12 seconds after it would set the offset to 1380, the IMC would drop out and kill the lock. What eventually worked, although it did not identify the problem, was going through that step by hand and scanning through the offsets slowly. I'm not sure if it will happen again so future operators be wary.

LOG:

• 15:15 Out of Observing for Maintenance Day
• 15:16 Richard to LVEA to check on the UPS for the PSL's NPRO
• 15:20 Jim B fixing October tconvert bug
• 15:27 Fil to EY starting interlock work
• 15:40 Richard starting work on WP6530 to open irises on IR cameras
• 15:50 Norco with LN2 delivery at the gate
• 15:55 Robert to LVEA for PEM testing
• 16:02 Karen to Mid Y for cleaning
• 16:27 Richard out and done
• 16:38 Lock loss
• 16:40 Carlos taking down the HWS machine to swap cards
• 16:42 Sudarshan to EY for PCal work
• 16:44 Robert out
• 16:48 Robert and Fellows to Electronics bay and LVEA
• 16:49 Kyle to EY
• 16:53 Loaded Sheilas SUS filters
• 17:08 Jason to PSL antiroom to grab a part.
• 17:24 Jason out, Karen to LVEA for cleaning
• 17:45 Kyle back from EY
• 17:54 Sudarshan leaving EY
• 18:00 Robert and Fellows out of LVEA and leaving for EY
• 18:02 Fil to sqeezer bay to grab items
• 18:30 Richard and guests into LVEA
• 18:45 Richard and guests out
• 18:52 Fil done
• 19:01 Nutsinee to LVEA to sweep
• 19:17 Nutsinee back
• 19:18 Robert and Fellows are back
• 19:18 Richard plugging in in LVEA
• 19:22 Richard out
• 21:31 At low noise. Robert to do HEPI measurements and then Jeff K will spend ~40min for calibration.
• 22:20 Jeff K starting calibration measurements.
• 22:59 Observing

Ran the full script for EX but had to cut EY short after about 35min. I did not get the chance to process the data yet, but I can do it tomorrow.

We were able to get images using the Pcal camera at ENDY today and these images will be used to determine the position of the Pcal beam. (Analysis to follow). We were not able to get down to ENDX because of tumbleweed infestation. We will probably try to get images from ENDX during Thursday's commissioning effort.

WP 6532

Updated GDS software Ubuntu 12, Ubuntu 14, and Debian 8 workstations.  This replaces foton with a new version that writes the gain coefficient in scientific notation with extended decimal places.  The issue is trying to find a format that will work for gain coefficient values of 479871010208.8750610351 and 1.827245000521226e-32, as an example.

Not sure anything changed since we were not locked at the time but I used the lens controller to open the iris all the way on ITMx and ITMy.  Without a beam I just have to believe they are all the way open.  Perhaps next time we are out of observing and locked I will shut and open the iris to verify its function.

To save its life span.

Found a power cord plugged into the wall opposite to HAM4 (now unplugged). Probably had been plugged since last week we did the HWS table work.

While the laser was down this morning, I took a quick measurement of the ETMX pit oplev damping loop.  It has about 5 dB of damping in a narrow range around 0.46Hz, and has zero phase and -10dB of gain at 1.5 Hz with no light in the arm.

Because the noise from these loops is limiting DARM at 10 Hz (alog 34735), I made a slightly more aggressive cut off (LP8 is intended as a replacement for LP10) which can be tried next time we have a chance.  This is the reason there are unloaded changes in the filter files for all 4 quads right now.

EX had a dip in pressure around March 9th from 97.7 to 97.5, but other than that all looks good.