Looking at the time delay as measured by the timing system:

Looked at the QPD Transimpedance Amplifier units at EX, S1102832 and S1102821.  We wanted to confirm the board versions. All boards D1001974 are version 2 and have the following configuration:
- C15 is removed
- R15 is 0 ohms
- JP1 has a jumper installed

Filiberto Clara

FYI, IAS:

Below is the table of the ETM and ITM bias slider offset  when the arm was aligned. Xarm data is right after we saw some green fringing (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=9064). I'm taking HIFO-Y data for Y arm (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=6627) even though HIFO-Y was more than a year after H2 EY was pumped down, as the slider was not calibrated during OAT, the data channels were all H2 so it's hard to track it down using data viewer now, and  I don't know how much the output matrix changed (the uncalibrated slider data is still available e.g. here: https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=3363).

Though EX, IX and IY all needed to be pointed down, EY needed to be pointed up (the slider sign convention is such that a positive PIT offset points the optic down).

Slider calibration is probably 15%-ish good or maybe better based on the measurement of baffle PD positions.

OTOH, the earth radius is about 6400km. The angle between the local vertical of EX and the corner is about 4km/6400km=630urad.

The default nds server is now h1nds0.  We will be performing maintenance on h1nds1 over the next couple of days.

A new version of gds software has been installed, addressing the following issues:

299, 328, 389, 428 - Any combination of start, stop, and BW that result in an fft of 512 points fails, due to how the fftw library is used by diag.  Fix by changing the way the fftw plan is generated, specifying FFTW_MEASURE instead of FFTW_ESTIMATE.

497 - Add option to foton to allow specifying a SFM name along with a filter file name.  See foton man page for details on the "-s" option.

500 - Removed Kaiser Window option from diaggui, it was never implemented.

511 - Changed foton to report that no design string exists for a filter if that is the case.  Previously this was reported as a different misleading problem.

519 - Allow IP broadcast for awg, tp discovery to be specified by an environment variable (LIGO_RT_BCAST) instead of assuming the broadcast address of the workstations.  

All these changes have been built from gds/branch/gds-2.16.9.  This affects Linux and Mac OS X workstations.  Existing diag or diaggui sessions should continue to work using the older software, but at some point we need to make network switch modifications that will cause the older software to stop working.  Advanced warning will be given.

Laser Status: 
SysStat is good
Output power is 29.3 W (should be around 30 W)
FRONTEND WATCH is Active
HPO WATCH is red

PMC:
It has been locked 6 day, 16 hr 34 minutes (should be days/weeks)
Reflected power is 1.1 Watts  and PowerSum = 12.1 Watts.
(Reflected Power should be <= 10% of PowerSum)

FSS:
It has been locked for 1 h and 6 min (should be days/weeks)
Threshold on transmitted photo-detector PD = 0.74V (should be 0.9V)

ISS:
The diffracted power is around 6.7% (should be 5-15%)
Last saturation event was 22 h and 26 minutes ago (should be days/weeks)

At ~0946 I valved out the South Actuators on BSC2.  There was a little pressure bump at the Pump Stations but I didn't see any HEPIs trip from that.  The Valve has been replaced and in is bleed mode.  The valves to the South Actuators were reopened ~0907 but I couldn't get the Mac Air to come alive to watch.  Looking back at the trends (attached) the reopening was worse than the closing.  I haven't heard any complaints but certainly those HEPIs under position control may have seen a wobble.  I opened and closed these valves very slowly to give the servo time to keep up but obviously even slower is better.

Looking at QPD amplifier chassis.

While searching for a flash of IR in TMSX IR QPDs, TR_B looked like it has a very slow low pass filter (attached).

The difference between TR_A and TR_B in the digital world is that the dewhitening (40:0.4) for the fixed whitening is off for TR_A and on for TR_B.

So it seems as if these IR QPDs are without fixed (non-switchable) whitening, but we're supposed to have these.

Later Filiberto will go to EX, open the chassis and change the jumper to get the whitening back.

I found the BSC 9 ISI tripped this morning, Stage 1 Watchdog trip, actuator limit was the first trigger. 

I also noticed that yesterday morning the ETM reaction mass was misalinged, and -600 coutns offset was added in ETMX M0 Locking filters.  I've turned both of these off, but still don't see a reflected beam, so I'm heading to the end station to have a look.

Evan, Kiwamu, Stefan

Tonight we left the PRMI locked, with a dither loop for ITMY, and a sqrt(POB18) gain scaling for MICH and PRC.
The ring heater was set at 0.75W for both upper and lower heater (total of 1.5W). The heat was turned on at 09:13:38 UTC.

The idea of this "low-heat" run is to keep the heating in a regime where the lens strength is roughly linear in the change in build-up. This should give us a good measurement of the lens-strength vs. time.

Stefan, Kiwamu

The PRMI lock is now quite solid. After we engaged a dither alignment system for ITMY, we turned on the ring heater on ITMY with a hope it is going to improve the mode matching.

• We set the modulation frequency back to 9099471 Hz which is the nominal value. This was for making sure that the separation of MICH and PRCL is good in REFLAIR_RF45. Although, we didn't do any quantitative assessment. So we have to revisit this.
• Both stages of BS-ISI and stage2 of ITMY-ISI were turned off because they were found to be too loud at low frequencies around 0.5 Hz and also at around 10 Hz (for some reason). Disabling them made the PRY noise quitter and the length RMS improved by a factor of 2 or 3.
• We successfully locked the PRMI with the sideband resonant with the settings shown in the attached screenshot.
• We found four oscillations very close to each other at around 300 Hz which are believed to be the BS wire violin modes. Two of them were so big and 6 orders of magnitude bigger than the noise floor.
• We put a double notch filter in LSC-MICH and PRCL filter banks. This let the mode ring down slowly.
• Also, at the same time we saw a power drop over a time scale of 2 minutes which seemed to be correlated to with the peak height of the violin modes. This behavior went away after the notch filters were installed.
• The PRMI lock was so stable that it did not spontaneously unlock.
• We set up an audio output path in LSC-DARM and used Chris's cool script, rockifo to listen to the sound of PRCL and MICH.
  • It is available in /ligo/home/christopher.wipf/Public/bin
  • For example, rockifo H1:LSC-DARM_OUT_DQ 16384 100
• We imported LLO's dither alignment stuff, but we realized that it only dithered the common mode of the power recycling cavity while we wanted to stabilize the ITMY angle drift. So we decided not to use it.
• We temporarily disconnected the cable for the ITMY green transmitted power and instead plugged in QMON of POPAIR_B_RF18. We used an SR560, AC coupled at 0.1 Hz with a gain of 5000 to whiten the signal.
• We then used the Y-arm dither alignment system to keep ITMY well aligned. We chose 1.7 and 2.4 Hz for pitch and yaw excitations respectively.
• We could close both pitch and yaw loop, probably with a UGF of 0.1 Hz for both.
• We turned on the ring heater at around 00:08 in local time with 10 W in both upper and bottom heaters of ITMY.