Shift Summary - Day

TITLE: 11/12 Day Shift: 16:00-00:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Corrective Maintenance
INCOMING OPERATOR: None
SHIFT SUMMARY:
LOG:

16:15 Switched Observatory mode to 'Corrective Maintenance'

16:20 Hugh, Jeff J and Charlie out to LVEA

16:21 Fil out to ISCT1 to disconnect cables for moving.

16:25 Gerardo out to LVEA - Output

16:29 reset HAM6 ISI WD

16:46 Hugh, Charlie and Jeff J out

17:00 Just notice Rick  in PSL enclosure

17:01 Bubba out to LVEA

17:09 Jeff B out to PSL

17:12 Richard just informed me that the Safety Interlock system is tripping due to a flaky cable at ISCT1

17:13 HAM6 vented and door(s) being prepped for removal

17:15 Chandra out to EY to prep for afternoon vent

17:24 Sheila and Fabrice out to HAM6 area

17:26 Chris S out to LVEA - door removal

17:27 Hugh out to LVEA

17:30 Cleaning crew out of LVEA

17:41 Cheryl back

18:01 set all sus in HAM6 to 'SAFE' - ZM1 is duplicated in main GUARD_OVERVIEW screen

18:02 Cleaning crew and Hugh out to EY

18:13 Gerardo and Kyle back

18:15 Fil back

18:30 Gerardo out to EY

18:45 Chris and Bubba back - removed end cap on HAM6

19:41 Corey out to LVEA - signature for WP and search for lexan viewport cover to move ISCT1

!9:50 Corey brought back WP for operator signature - back out to LVEA to prep ISCT1 for move

20:06 Jeff B and Peter K out

20:06 cleaning crew back from EY

20:30 Rick out of PSL

20:53 Richard out to LVEA - looking for Fil

21:00 E Stop faults reset

21:19 Gerardo, Kyle, and Chandra out to LVEA - they will begin to vent HAM1 ahead of schedule - doors will stay on for now

21:22 Chris S out to EX - greasing in fan room

21:28 Chandra back and out to EY to begin vent

21:53 Jason and Peter out to PSL

21:58 Bubba out to LVEA - checking area to set HAM1 doors

21:58 Hugh out to LVEA-locking HAM1 HEPI

22:05 Dave Barker out to End Stations -checking comps to see why sei won't reset

22:15 HAM1 vented - VAC team out to EY

22:22 Fil and Richard back

22:41 Chris S back and out to LVEA

22:42 Sheila, Haocun, Nutsinee, and Fabrice out to HAM6 - Squeezer table

23:13 Jeff J out to LVEA - checking status of work

23:20 Dave Barker back

23:33 Jeff J back

23:37 Daniel and Dan to EX - Hartman table work

OpLev Inspection - Weekly FAMIS#11191

PIT alignments have been nominally good. The deviance at the earliest point in the trends on ITMX and ITMY I'm going to attribute to the vent work.

I'm going to say that's a ditto for the ITMY YAW.

Not sure what to say about the sums. They are affected by the ever-slightly changing alignment(s). None of them show imminent death though the counts on the ETMs are historically a little lower than the rest (except for the BS)

PSL Weekly Status FAMIS #10986

Laser Status:
Front End Power is 0.01014W (should be around 30 W)
70W Output Power is 2.425W
Front End Watch is RED
70W Watch is GREEN

PMC:
It has been locked 0 days, 0 hr 0 minutes (should be days/weeks)
Reflected power = 0.0367Watts
Transmitted power = -0.0226Watts
PowerSum = 0.014Watts.

FSS:
It has been locked for 0 days 0 hr and 0 min (should be days/weeks)
TPD[V] = 0.04675V (min 0.9V)

ISS:
The diffracted power is around 0.14%
Last saturation event was 0 days 6 hours and 34 minutes ago (should be days/weeks)

Possible Issues:

Vent activities this week including but not limited to: Mode matching work, 70W amp remounting, plumbing work, and IO work

 

BruCo scan for ~100 Mpc time

• Updated BruCo scan using the best sensitivity so far (reporting above 100 Mpc), between 1226014475 and 1226014475+400s

https://ldas-jobs.ligo.caltech.edu/~gabriele.vajente/bruco_1226014475/

• Below ~17 Hz, dominated by DHARD pitch and yaw

• INP1 and PRC2 yaw between ~15 Hz and 30 Hz. This coherence is seen also in most of the REFL WFS and most interestingly in some IMC transmission signals, like for example the ISS second loop QPD. I suspect this is an indication of real input beam jitter. Incidentally, sidebands around the 60 Hz line are also coherent with INP1 and PRC2

• There is some interesting coherence with OMC_A_YAW_OUT, but this might be related to the DHARD motion

 

• at the time, there was a large PCAL line at about 35 Hz, and a lot of coherence with PCAL signals, not only at the line both also broadband. I'm not sure if this happens in the normal state or if there was some injection going on.

 

• SRCL noise is quite close to the sensitivity between 20 and 150 Hz. PRCL is also close.

 

• A few peaks are coherent with the PSL periscope accelerometer (about 177 Hz, 223 Hz, 483 Hz, 542 Hz)

PSL Weekly Report - 10 Day Trends FAMIS #10583

IMC signals from locked before shutter closed

Based on a relatively quiet stretch, before the IMC lost lock, 1226067950 to 1226067960. Plots showing the Bullseye and IO signals attached.

PSL laser cooling line work today

PeterK, JeffB, RickS

This morning, Peter set irises to mark the beam pointing in advance of the water line work.

We then installed stops to register the position of the Front End baseplate, removed the pump fibers, moved the Front End box to the edge of the table,  removed the 35-W amplifier from the Front End box, and replaced the "quick connect" water fittings with 8 mm push-to-connect tubing fittings (see attached photos).

We did a pressure test with the 35-W head plumbed in the new configuration but outside the Front End box to check for leaks before re-installing it and moving the Front End box back into location.

We also removed all the flow-regulating valves from the supply-side water manifold for the three circuits: 35-W amp, 70-W amp, and high-power shutter.  We moved the flow meters to the return-side manifold so that they would respond to a leak in the water path by shutting down the chiller before exhausting the water supply.

Initial flows were: 1.3 lpm, 2.7 lpm, and 1.4 lpm for the three paths.  We then installed a 3-4 ft. section of 6 mm (OD) tubing in the 70-W amp path.  The resulting flows were: 1.4, 1.9, and 1.4 lpm.  So we added about 40 ft of 8 mm tubing (we didn't have any more 6 mm tubing) to get flows close to the 1.5 lpm target: 1.4 lpm, 1.6 lpm, 1.5 lpm (see attached photo).  Note that the "pwrmtr" signal is really for the HP shutter).

Note that we have not yet modified the chiller configuration to reduce the laser-end water pressures, now about 70 psi on the supply side and 50 psi on the return side, by throttling the chiller output to reduce the pressure drop across the heat exchanger on the return-side path to the reservoir.  We plan to do that later in the week.  We are waiting on a part that is schedule to arrive today or tomorrow.

Our detailed task list is also attached for future reference.

 

Safety Controls and Slow Controls

With PSL being down this morning replace and cleanup fiber cabling in the MSR and CER. This work effected both the Safety and Slow Controls systems.

ISCT1 Field Cabling disconnected

In preparation for ISCT1 being moved, field cabling was disconnected this morning.

Changes to Tuning Parameters at EX for Temperature

I have adjusted the tuning parameters at EX, namely the Proportional and Integral on the Face-Bypass Dampers to try and slow the temperature swings. Although we are still maintaining the desired temperature, the swings are apparently to severe for the BRS. 

WP7937 install 4th digital video server

Carlos, Dave

We have installed the new computer in the rack slot formerly used by h1auxscript0. It is unclear that this aux machine was actually doing anything, so we may leave it out of the rack for now. The new video server will be called h1digivideo3 and run Debian9.

update coupling to green light to fiber (now 85+/-1%)

The updated mode-matching solution to account for the noise eater alog(44783) assumed a waist at the coupler of 750um (because that was in the thorlabs documnentation recommended). However a measurement indicates a waist of 500um out of the coupler.

I adjusted the solution SHGtoFiberAM.pdf alog(44783) to move the  ROC75 lens 6cm closer to the SHG the ROC200 lens 1-2 cm further away from the SHG and the fiber coupler 10 cm further away from the SHG to get a waist of 550um.

To get a waist of 500um would take a relatively major path rearrangement and with the vent only hours away it was a little risky to do it now, I will fine tune after the vent and hopefully the proper solution will be significantly above 85%. 

EY systems ON for vent

Turned ON air compressors in chiller yard for instrument air, QDP80 is ON, and purge air skid is ON.

GV 1,2 hard closed and HAM6 vented

Hard closed GV 1,2 this morning and then vented HAM6 (~45 min. vent). Dew point measured -45degC just before valving in purge air.

HAM6 cell phone vacuum alarm has been silenced for vent

I've put in a temporary bypass for HAM6. We'll bypass others as the vent progresses.

Bypass will expire:

Tue Nov 13 08:36:07 PST 2018

For channel(s):

    H0:VAC-LX_Y0_PT110_MOD1_PRESS_TORR

 

DCPD whitening and DARM offset

We observed some improvement with larger PD current yesterday. It was not clear to us why. There is some chance that a calibration issue is fooling us, but at the low frequencies we were looking at the calibration should only depend on the actuator.

Either way, to get to the bottom of this, we revisited the whitening of those PDs.

Currently, we are using 10mAmp per diode in regular operation. If the violins are smaller (as the were yesterday) we can increase the DARM offset to operate at about 15mAmp per diode, but that becomes a problem when the violin modes are high.

Attached is a plot of the whitening situation of out OMC DCPDs in full lock, with about 14mAmp per photo diode.

ndsope inset top: ADC signed of the photo diode
ndsope inset bottom: photo current on the photo diode
dtt red: PD signal in cts ADC (which is loop gain suppressed, hence the dip at 30Hz amd the peak at 100Hz)
dtt blue: dark noise
dtt green: possible option with current whitening filters: additionally engage a 2nd whitening stage plus the low-pass. Reduce the DARM offset by 3.2dB to get the violin mode peaks back down where they were.

It would be worth testing the green configuration, just to exclude that we have some load-dependent dark noise after the whitening stages.

Here is a loop gain corrected plot showing our dark noise headroom my worry is that there might be increase dark noise under load, but running on the green configuration should tell us that.

Common mode board swapped

Fil Marc Daniel

We modified the spare CM board (s/n S1102622) according to E1800338 and swapped it with the existing one (s/n S1102621). This modification includes low pass filters for the DAQ readbacks, and a frequency change in the first two boost stages to 10Hz/500Hz.

Sources of peaks in jitter spectra

The figure shows spectra from the 4 angular IMC WFS DC channels with labeled peaks. Eight of the peaks between 80 and 1000 Hz are from optics or structures on the PSL table, two were from IOT2 and four haven’t been identified. The unidentified peaks were not excited by our PSL injections, even the global ones. It is possible that they are associated with structures that weren’t excited on IOT2 or in HAM2, or they may be associated with structures on the PSL table that we weren’t able to excite.

The identified sources are table resonances, periscope resonances and optic mount resonances. All optics that produced peaks in the spectrum were downstream of the PMC and were mirrors rather than through-optics like lenses, as would be expected.

The figure also shows the location of the sources in the PSL, as well as samples of the bowing and tapping data used to make the identifications.

Robert, Craig

https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=44460