In preparation for my rezeroing of the active oplevs tomorrow I've taken 7 day minute trends of these oplevs.

LHO's second-Saturday public tour occurred on the afternoon of 11/14.  Arrival time at LSB = 1:00 - 1:30 PM.  Departure time = 3:45 - 4:15 PM.  Group size = ~30 adults.  Vehicles at the LSB = ~15 passenger cars.  The group was on the overpass near 2:50 PM and in the control room from about 3:10 to 3:40.  Landscapers were working on tumbleweeds near the corner station near 2:45 PM. 

TITLE: "11/16 [OWL Shift]: 08:00-16:00UTC (00:00-08:00 PDT), all times posted in UTC"

STATE Of H1: Observing at ~80 Mpc

SUPPORT: Jenne

SHIFT SUMMARY: Spent first couple hours with initial alignment and lock acquisition. Issue with ALSY* both during initial alignment and locking ALS. Later OMC flashed at the wrong mode. An attempt to adjust OMC alignment was made but it seemed to fix itself somehow. Low wind and nominal EQ seismic band through out the shift. Useism ~0.5e-1 um/s.

INCOMING OPERATOR: Jim

ACTIVITY LOG: See alog23433 and alog23429 + comments therein.

* when I said I had problem with ETMY I actually meant ALSY. There's no problem with ETMY. 

Robert, Jess, Nutsinee

Back in September Robert and control room folks did an injection of "5 people jumping in sync" (alog21180). A followup showed that the injection indeed coupled into DARM (alog21191) from ~10-400Hz (an omega scan of a jump can be found here). So I continue to followup the coupling mechanism hoping it would shed some light on how ground motion coupled into DARM (we suffer a slight range drop daily during high traffic time). Using Robert's Acoustic Coupling Functions (alog22797 figure 9) I was able to pin down the coupling mechanism above 100Hz. Figure1 shows the calibrated DARM and the PSL periscope accelerometer spectrum at 100-400 Hz.

• At 210Hz periscope amplitude measured 4e-4 m/s^2/sqrt(Hz), multiply by the coefficient of 3e-16 the predicted DARM becomes 12e-20 m/sqrt(Hz). The actual DARM amplitude measured 10e-20 m/sqrt(Hz). Off by a factor of 1.2. 
• At 120Hz  periscope amplitude measured 2e-4 m/s^2/sqrt(Hz), multiply by the coefficient of 3e-16 the predicted DARM becomes 6e-20 m/sqrt(Hz). The actual DARM amplitude measured 7e-20 m/sqrt(Hz). Off by a factor of 1.2. 
• At 360Hz periscope amplitude measured 1.2e-4 m/s^2/sqrt(Hz), multiply by the coefficient of 3e-15 the predicted DARM becomes 3.6e-19 m/sqrt(Hz). The actual DARM amplitude measured 1.7e-19 m/sqrt(Hz). Off by a factor of 2.

The predicted DARM value is expected to agree with the actual measurement within a factor of 2. Thus it is reasonable to blame PSL periscope for ground-to-DARM coupling at above 100Hz. However, at f < 100Hz the coupling mechanism is still a mystery (figure4).  Robert wasn't able to make periscope motion couple into DARM at low frequency (refer to figure 7 of alog22797). However, we were able to rule out HAM2 and HAM6 as coupling sites based on the upper limit (alog22797 figure 3 and 6). Figure 2 and 3 attached show that both HAM2 and HAM6 GS13 rise about a magnitude above the noise floor, while the upper limit from Robert's alog is about 1.5-2 order of magnitude. Meaning, shaking HAM2 and HAM6 GS13 at 2 order of magnitudes above its noise floor at low frequency didn't couple into DARM.

Whatever the coupling mechanism is at low frequency, we believe the same mechanism is responsible for HVAC coupling into DARM. Figure5 shows DARM spectrum during the HVAC injection time (alog22532). HVAC noise shows up in DARM at 20-100Hz.

I accepted SDF change of OMC alignment. I didn't want to risk losing lock by reverting it. Screenshot of the old and new value attached below. This might have caused by me attempting to touch the OMC alignment slide bar earlier.

I trended all the optics that I know are in the green light path back to where they were before we lost lock (~10hours ago). TMSY alignment was off by 5.6 um. Adjusting TMSY alone improved the flashes from 0.4 to 0.6. The rest was the combination of ITMY and ETMY adjustment. Seems like I have some magic fingers =p

One mistake that I used to make is that touching either ETM or ITM without realizing that both mirrors have to be aligned with respect to one another. Other than looking at the camera and dataviewer try imagining how optics actually move could be helpful.

TITLE:  11/16 OWL Shift:  00:00-08:00UTC (16:00-00:00PDT), all times posted in UTC     

STATE of H1:  ALSy not locking

Incoming Operator:  Nutsinee 

Support:  Talked with Jenne a couple of times (as well as Mike)

Quick Summary:

Tonight was a bust.  ALSy was giving Jim trouble at the end of his shift, and it continued that way for all of my shift.  Basically, having trouble aligning ALSy.  Not able to get to a 0:0 mode (and this was with tweaking ETMy, TMSy, & ITMy).  Frustrating shift.

ALSy Notes:

• Checked ALS Laser Power (Diode Head #1 & #2):  Look stable for last few hours/days.
• Temperatures in LVEA & EY:  EY looks pretty flat.  LVEA had some excursions before the lockloss, but nothing out of the norm looking over many days.
• Oplevs (ETMy, ITMy):  Good
• Thought it was worth noting that the spot seems to move a little for ALSy (but maybe it always moves like this.
• Jenne pointed me to archives of the digital cameras (/ligo/data/camera/archive/2015/11/16/[file]).  So attached is a comparison to an ALS camera shot today & Saturday afternoon:  Basically the spot looks to be in the same area (no gross misalignment of the beam spot).  Thought of addressing cameras when we saw a message in the ALS_YARM log stating:  "Camera centering too far off.  Need to turn on slowly."
• Have basically went through several iterations of alignment here.  Have restored ETMy/ITMy/TMSy to state before lockloss, and have tweaked the alignment several times (as alogged earlier).

To Do :

Hoping a new set of eyes (Nutsinee's!) has better luck here.  Jenne and I both think it's an alignment issue.  And since it's ALSy, the only knobs to turn are for ETMy/ITMy/TMSy.  So mabye I just didn't have the magic touch:  I just wanted a 0:0!!!!

I picked Jenne's brain for anything I could pass on to Nutsinee and basically all we have is:

• Work on alignment.  Get 0:0 mode.
• Then see what happens once you get it (hopefully WFS likes it).
• If WFS drive off alignment of a 0:0, try disabling WFS DOF3 PIT (on ALSy Overview), minimizing it's input, and then re-enable.

Rough Night.

Jess, Laura, Paul

We have been following up on the periodic 60Hz EY glitches which have been seen at LHO since at least June (alog 18936). These glitches are witnessed by various magnetometers and couple into DARM.

It seems that the glitches indicate the switch-on of some electronic device. Spectrograms of H1:PEM-EY_MAG_EBAY_SUSRACK_QUAD_SUM_DQ show lines at several frequencies (30, 42, 60, 80, 120 Hz) that start when the glitch occurs, then stop with a rather softer glitch about 27 minutes later. Attached are spectrograms from yesterday and last Thursday. There doesn't appear to be anything correlated in the HVE or H0:FMC channels.

We recently investigated something similar at LLO (alog 22549), which we managed to trace to an unmonitored air-conditioning unit outside the EY station. The behavior at LLO is somewhat different in that the glitch is much louder and the subsequent noise (in both PEM channels and DARM) is quieter, as well as the fact that it stays on longer each time. However, because the turn-on and turn-off are so predictable it should be possible for someone to go down to EY and listen for anything turning on and off at the expected time.

Returned ETMy, ITMy, & TMSy to state they were before last lockloss (by using the M0 & M1 DAMP p/y INMON values & using sliders to return SUS to these values).  

Still have issue of not being able to get ALSy power over 0.5.  The best I could do was actually up to 0.65 with a 0:1 mode (I changed trigger threshold to 0.8), but as soon as I took the threshold down to 0.5, the WFS engaged and drove the alignment off (not surprisingly since what they had was a bad 0:1 mode).

I have had zero luck at getting a 0:0.  Not sure what other knob I can turn to help me get out of this bad alignment hole.

Have continued Jim's work on trying to get ALSy to a point where WFS can take over but have not been able to get to a 0:0 mode, and thus have not had much luck getting powers much over 0.5 (when WFS can kick in, after 10sec).

The problem from my point of view, is that ALSy will lock on a mode 0:1 (and uglier modes) for only a few seconds--why can't it stay in a mode for longer so I can get an idea of which way to move sliders(!).  This isn't long enough for me to tweak and observe the power to improve it.  I wish I could get it to a 0:0, because then I could atleast get it above 0.5.

I started out just moving ETMy, but at this point, I have also been adjusting sliders for TMSy & ITMy to no avail.

I did finally get a 10+sec stretch of 0.5 - 0.6 (which was a 0:1 mode), but when the WFS kicked in, they drove the power down & knocked it out.  SOOO, I really want to get a 0:0 with any power and try to get WFS to help out.  

SDF shows no difs for the ISIs of the Y-arm.  (SDF isn't useful for the SUS's because they are always RED in this state).

I have previously shut down the HVAC over the whole site, increasing the inspiral range (Link, Link). The PEM injection report (Link) indicates that coupling in the 5-80 Hz HVAC band is largest at the corner station so I tried shutting down just the corner station. Figure 1 shows that a shutdown of the corner station HVAC reduces the DARM floor above 80 Hz. Figure 2 shows that SF1,2,3 and 4 contribute little, but SF5, 6 and the chiller pump (actually the turbulence in the system), are the worst contributors.   

Nov 15 UTC

AHU 1-4 and chiller pump off 16:40:00 - 16:42:25; Back on 16:50:00-16:51:30

AHU 1-4 and chilled water pump off 17:00:00-17:01:30; Back on 17:10:00 - 17:11:30

AHU 1-4 and chilled water pump off 17:20:00-17:21:45; Back on at 17:30:00-17:31:30

AHU4 off 20:15:00 -20:15:30; Back on 20:30:00 - 20:30:30

AHU3 (SF5 and 6) off 20:45:00-20:45:30; Back on 20:55:00-20:55:30

AHU1,2 SF1,2,3,4 off 21:02:00-21:07:00; Back on 21:17:00- 21:17:30

SF1,2,3,4,5,6 off 21:30:00 - 21:30:30; Back on 21:41:00 - 21:42:00

Chiller pump off 22:13:00-22:13:30; Back on 22:33:00-22:33:30

SF5,6 off at 22:40:00-22:40:30; Back on 22:51:00 to 22:52:00

SF1,2,3,4 off 23:00:00-23:00:30; Back on 23:10:00-23:10:30

AHU4office off 23:17:00 to 23:17:30; Back on 23:27:00

Title: Day Nov 15th Summary, 16:00-00:00UTC

State of H1: initial alignment

Shift Summary: Was a good shift until a little bit ago

Shift Details:

IFOwas locked when I arrived, Cheryl reported a quiet shift. About 18:00 winds started picking up, see my log 23419 (where I briefly tried to get ETMX ISI to settle down by turning off a boost to no effect), to eventually topping out over 40mph. ALS and ASC both showed a lot of motion. The IFO stayed locked through the worst of it and winds calmed until 23:30, when the wind picked back up to just over 20 mph. Then the lock just broke, no clear cause. ASC was somewhat rung up, as was ALS, but not as much as when winds were ~40mph. Now ALS-Y is being difficult, I couldn't get it to re-lock. Corey is starting an Initial alignment, but not having much more luck than I did.

I talk about a "new" filter in this alog. Before I get yelled at, I only tested it, I asked first, we are not running it anywhere, no changes have been made to the ISI configuration, the foton files in the SVN are all still current. Thank you.

On Friday, high winds and high microseism were making locking impossible, so I took the time to mess around with sensor correction. The current X/Y rdr sensor correction was designed to give very minimal gain peaking, while providing extra isolation around the .46 hz quad resonance. This helps LHO out, because it is difficult to roll off a 90mhz CPS blend off quickly enough to get good isolation at half a hz. At LHO we typically use a 90mhz blend because our useism is low enough that we can tolerate being locked to the ground in the .1-.3 hz band, and the 90 mhz blends have less gain peaking at frequencies ( < .1hz ) that cause problems for the ASC loops. When useism is high, however, we have to use a 45mhz blends, but these blends couple in more platform tilt at bad frequencies, a problem that gets amplified when winds are high. I wanted to see if it was possible to change the sensor correction  to provide some isolation at the microseism, while giving up the gains at half a hz. I based my design on the current one, I just pushed the region where the phases matched up to lay on top of the microseism peak. The fifth picture is a quick and dirty plot I used to design the filter in Matlab. Blue is the current filter, green is my new filter, red is a ratio of transfer functions that indicate the "ideal" filter.

First plot is the T240s for the different configurations I tried. Red is the nominal configuration, 90mhz blends .46hz sc notch, blue is the high microseism configuration, 45 mhz blends .46hz sc notch. Green is the 45 mhz blend with useism sc, brown is the 90mhz with useism sc. This color key holds for all my other  plots.

 ---Blue is pretty good, until you get down to .1 hz, then ISI tilt (RY to X coupling on the T240s)  and gain peaking in the blends make ASC /LSC difficult. This is why 45 mhz blends don't work with high winds. The ground was a little worse for this  measurement below .1 hz, but I think it only explains half the difference here, at most.

----Red is okay until .1-.3 hz, where we know the microseism was moving the mirrors too much.

---Green should be compared to blue, as it indicates the differences in the performance of the two sc filters. The performace is indeed worse at ~.5 hz, but better between .04 -.2 hz. I really expected this to be much worse below ~.1 hz, instead of only a little worse over .02-.03 hz.

---Brown should be compared to Red, again showing the difference in sc performance. Story is the same as green, better at .04-.2 and worse at ~.5 hz.

The second plot is the CPSes, the color key  the same, blue & green compare the two sc filters with 45mhz blends, while red & brown compare the two sc filters with the 90 mhz blends. I think the conclusions are the same, but the CPSes show the low frequency story better.

Third plot shows the ground at EY at the times I was taking each measurement. Clearly the ground at .05 to .09 hz was a little worse than the other times, but I think it accounts for at most half the difference. The fourth plot shows the CPS and the ground motion for the two sc measurements with 45 mhz blends, which were the two extremes of ground motion. Maybe it's not clear, but I think solid blue is higher above dashed blue, than solid green is above dashed green around .1 hz. I should have gotten the ground to CPS tfs....

I don't know if the losses at .5 hz are too much (as much as a factor of 10), I didn't look at oplevs, there were no cavities when I did this.  Frankly I'm surprised it worked at all. But maybe this is something worth exploring. I would like to try this again when the ground environment is making locking impossible.

Winds are starting to come back up. Before I noticed that I saw the ETMX ISI was starting it's slow ring up. Suspecting the lock was not going to last long I briefly took the IFO out of observe, so I could try disabling the boost on the ETMX ST1 X isolation bank, as that had been successful in the past of settling the ISI down (based on one data point, so it may not be true...). This didn't have any effect however, so I've put the boost back on, and gone back to observing. The wind seems to be getting worse, so this lock probably won't make it much longer. Useism is getting better, so we might be able to lock again, if we switch back to 90mhz blends, but the current lock probably wouldn't survive the switch.

I turned the boost off at about 18:34, then back on at about 18:48, UTC.

After the alignment tweaking with Jenne, and getting through PRM, I continued with the Initial Alignment.  The Dark Michelson came up on its own fairly well aligned and I only barely touched it.

After the IA, attempted locking.  First attempt was on an ugly DRMI mode.  Second Attempt locked DRMI within 10-15min.  Proceeded through Guardian States.  First hitch was at ENGAGING ISS 2ND LOOP.  Ended up having to Engage by hand (via Kiwamu's alog); this was scary as it's hard to engage when output is close to zero---had a big glitch when I engaged, but it rode through (yay!).

Finally made it to NOMINAL LOW NOISE with range around 80Mpc (but had a few DIFFS on SDF).  The Diffs were:

Input Pointing Diffs:  

• IM1 & IM3 pointing changed at ~14:45 PST today (Jim?)
• RM1 & RM2 pointing changed by me this evening

Some ISIs in GS13 LO Gain Mode Diffs for HAM2, HAM5, ITMx

• Called Jim and he said these were probably stragglers left in LO gain from our seismic issues of the last few days.  He said switching to HI gain might drop H1 out of lock...I ACCEPTED the input point issues above first, and then switched HAM2 GS13s to LO gain:  This knocked H1 out of lock.  I switched HAM5 & ITMx ISIs to LO gain while down.

Now working on getting H1 back UP (& going to have dinner soon).