TITLE: 05/19 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Lock Aquisition
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    Wind: 27mph Gusts, 19mph 5min avg
    Primary useism: 0.08 μm/s
    Secondary useism: 0.17 μm/s
QUICK SUMMARY: Wind is starting to pick up a bit, let's see what else today has in store for us!
 

Transition Summary:

Title:  05/18/2016, Evening Shift 23:00 – 07:00 (16:00 – 00:00) All times in UTC (PT)
State of H1: IFO locked at DC_READOUT with 2.1w of power. The wind and seismic are a bit rung up but do not seem to be effecting the lock.    
Commissioning: Several commissioners working on IFO.
Outgoing Operator: Ed
 
Activity Log: All Times in UTC (PT)

23:00 (16:00) Start of shift
23:00 (16:00) Gerardo – Back from filling CP3
23:47 (16:47) Sheila & Haocun – Going to ICST1
23:50 (16:50) PSL – Down Flow Sensor error 1 – Notified Peter
00:18 (15:18) Sheila & Haocun – Out of the LVEA 
00:40 (15:42) Sheila & Jeff B. – Into LVEA to reset the NPRO Noise Eater 
01:30 (18:30) PSL – Down again due to same sensor flow error – Notified PSL team



End of Shift Summary:

Title: 05/18/2016, Evening Shift 23:00 – 07:00 (16:00 – 00:00) All times in UTC (PT)
Support: Jenne, Sheila, Haocun, Evan, Craig, Ross
Incoming Operator: N/A 

Shift Detail Summary: High winds at the site (up to 36mph), having trouble getting past LOCKING_ALS. Hugh & Jeff B. working with the BRS blends. At 23:50 (16:50) PSL down due to flow sensor error on PSL Crystal Chiller. Peter working on recovery.  PSL ran until ~01:30 (18:30) when it took another flow sensor error. Spoke to Jason and Peter. Going to leave the PSL down tonight. The backup chiller (Wallace) has been prepped for installation. The plan is to swap out the primary chiller (Gromit) with the backup chiller tomorrow morning.  

C. Cahillane

I have looked at the actuation strengths to check the covariance between the actuation stages for each of the four measurements.  
The four measurements are the three calibration week actuation measurements on August 26, 28, and 29, and the Post O1 January 7 measurement.
The covariance was calculated by taking the residuals of the fitted actuation strengths and comparing points between L1 and L2, L1 and L3, and L2 and L3 at the same frequency for each day's measurement.

The different dots in the covariance plots correspond to frequency.  The dark blue is low frequency, and the light orange is high frequency.

The covariance is on the same order as the overall variance for each actuation stage.  Worse still, it is positively correlated, meaning we may have underestimated uncertainty by ignoring these terms. 

My results also indicate the measurements may be inconsistent between days.  The August 28 measurement inexplicably displays no covariance between actuation stages, while all of the other measurements do.  Jeff has tried looking at the optical gain fluctuations during each day's measurements, but this doesn't appear to be the cause.

   After Peter recovered the PSL, it ran until ~01:30 (18:30) when it took another flow sensor error. Spoke to Jason and Peter. I am going to prep Wallace tonight and will swap out the chillers tomorrow.  

Sheila, Haocun

We tried with the POP X path with 36MHz to control PR3, and phased each quadrant it to minimize the Q signal, as shown below. We used -1 in the matrix for Pitch. This is fine for Pitch, but in Yaw, there is an offset between the new signal and the REFL signal. So in the afternoon, we changed to use 45MHz demodulation and changed the dark offsets. Then the laser broke down. 

In trying to determine whether or not there was a water leak with the laser, the humidity sensor in the high
power oscillator was looked at.  In doing so, a interesting coincidence was noticed - the reason for which
is not obvious to me (anyway).

    WaterTrip1.png shows the humidity sensor output from last night when Jeff reported that the laser tripped.
WaterTrip2.png shows the same signal from when the laser tripped a few moments ago.  Both plots show a small
oscillation-like variation in the humidity.  The same behaviour shows up in the temperature sensors mounted
to the laser base plate.

    Cave flow sensors for heads 3 and 4.

Because PSL power fluctuation impacts the maximum IMC input power (the amplitude variable for the angle-power calculator), one thing we could do is to keep an eye on H1:IMC-PWR_EOM_OUT16 chanel. The difference between the EOM channel and the actual max power output from the RS is roughly 1W (as of yesterday with PWR_EOM gain of 0.916. I assume this can change).  So replacing "Power in (W)" variable in the calculator with (PWR_EOM_OUT_16) - 1 should do the trick (I did the calculation and it seems to work out. Again, watch out for the PWR_EOM gain). First attachment is the maximum IMC input power compared to the EOM power when I ran the RS script yesterday. Second attachment shows increase in EOM _OUT16 today and corrected IMC input power towards the end of the plot (2W instead of 2.15W). Third attachment is the PWR_EOM filter as of today. It would be nice if EOM power agrees with the maximum IMC input power unless we really lose 1 W somewhere on the table (I see that there's another beam dump after the RS in the PSL layout).

  23:50 (16:50) PSL down due to flow sensor error on PSL Crystal Chiller. Peter is working on recovery.  

1/2 open LLCV bypass valve, and the exhaust bypass valve fully open.
Flow was noted after 82 seconds, closed LLCV valve, and 3 minutes later the exhaust bypass valve was closed.

(Keita Daniel Jim)

We copied the auot-centering logic from the green WFS to POP_X. The centering loops will be automatically engaged, when the NSUM threshold of the DC channels is above 0.5. It uses the integrator modules to add offsets at the output. The loops were adjusted for 10 Hz bandwidth.

I used diagnostic breadboard (DBB), with ISS first loop on and DBBPMC (not real PMC) unlocked, to use the DBB WFS DC output as the jitter sensor.

Right column is with the frontend beam into DBB, and left is with high power laser beam. QPD_[12]Q[XY] means WFS[12] DC [YP], and QS is the DC sum. I pressed "pre-align" so the beam comes to the center of the sensors, and the measurements were made while the pre-align servo was on. The total power for both of the beams sampled are about the same.

As you can see, the frontend beam is much quieter than the HPL beam over the entire measurement band, it's a factor of 40 or 50 larger at 100Hz.

The coherence between the HPL jitter and intensity to the PMC transmission RIN is large for the entire band (left bottom). Blue and brown show PIT to intensity coupling. Pink and cyan show intensity to intensity coupling. The fact that the coherence is high for PIT (Y) but not for YAW (X) means either the alignment into PMC is off in PIT, or some other jitter-intensity conversion mechanism e.g. clipping or QE dependence on the beam position is worse/steeper in PIT.

Just to see how this is different at different measurement point, orange and black are the PIT to intensity and intensity to intensity coupling measured by (one of the?) IO diodes downstream of the main EOM. (I know nothing about the analog filtering of this diode.) There's some but not huge difference in PIT-to-intensity coherence. Probably PIT-to-intensity conversion mechanism is more or less common to these two, e.g. alignment into PMC.

The antiwhitening filters for POP_A_LF and REFL_A_LF did not correspond to the analog whitening on the chassis in ISC R4.

• POP_A_LF had no whitening, but the digital SFM had two antiwhitening filters engaged. I turned both whitening filters on. This makes the dark spectrum a factor of 2 or so above the ADC noise.
• REFL_A_LF had no whitening, but the digital SFM had one antiwhitening filter engaged. I turned off the antiwhitening filter. We should re-evaluate whether we want to turn on some whitening.

ISS has been oscillating at around 1.x kHz since 6:30 AM or so (first attachment). This happens once in a while and no fundamental cause has been identified yet.

Anyway, I disabled ISS and turned it on again for recovery, and in doing so I found another familiar failure mode caused by the diffraction power set too small (H1:PSL-ISS_REFSIGNAL was set -1.7).

Whenever AOM hits the bottom, ISS receives a huge kick and the AOM output goes very high, and for whatever reason it comes down very slowly and eventually settles. I wonder if this slow impulse response is an intended behavior or not. Anyway, whenever you enable ISS this happens at least once, it seems. If the diffraction power is set too small, the AOM will hit the bottom again, and the process repeats itself (second attachment). If you start with a higher diffraction and then slowly bring it down, it will work for a while until a big intensity glitch hits.

The third attachment shows the ISS first loop with barely large enough diffraction (H1:PSL-ISS_REFSIGNAL= -1.64, which resulted in 10+ percent of mean diffraction) for the intensity noise as of now. The servo was turned on at t=-190 sec or so on the plot. You can see how frequently the servo gets close to bottoming out.

I increased the diffraction further (fourth attachment, H1:PSL-ISS_REFSIGNAL=-1.6) and adjusted the offset.

J. Kissel

While in the systems meeting today, we'd wondered if the PSL IO Chassis had any spare DAC channels available for use with the newly planned ISS 2nd loop upgrade (see D1600175). Though a PSL DAC channel list is available (see T1200092), it's not really organized to nicely answer the question. As such, I've gone through the PSL front-end simulink models in an attempt to better answer the question. In summary, there are 11 spare DAC channels, some of which are grouped in such a way that they might have independent AI chassis spigots such that installation of new channels for the proposed upgrade to the ISS Second Loop electronics should be easy. 

There are 4, 16 channel DAC cards in the PSL IO chassis. 
On DAC 0 (card_num=0), which is nominally the ISS DAC card, there are no spare channels.
On DAC 1 (card_num=1), which is nominally the FSS DAC card, there are SIX spare channels.
On DAC 2 (card_num=2), which is nominally the PMC DAC card, there are FIVE spare channels.
On DAC 3 (card_num=3), which is nominally the DBB DAC card, there are no spare channels.
Note I say that these DAC cards "nominally" associated with a given function and/or top-level front-end model, but there are many other instances (namely SEI and SUS models) where not only are there multiple DAC cards in a given model, but there even instances where different models share (obviously different channel on) the same DAC card.

The spare channels are specifically (where channel counting starts from 0)
DAC_1_8
DAC_1_9
DAC_1_10
DAC_1_11
DAC_1_13
DAC_1_14

DAC_2_0
DAC_2_12
DAC_2_13
DAC_2_14
DAC_2_15

I attach a full list of the DACs channels identified by their channel names (which hopefully is a good enough proxy for their use). I would attach screenshots of the models, but the output ports are labelled too poorly at the top level for it to be helpful.

PS. This is the first time I've had to look at these PSL models: 
- There are lots of wasted channels (many cases of EPICS records being fed into full filter banks -- likely just to get a fast-channel test point -- the need for which I don't understand). Cleaning this up would likely make a non-negligible impact on the model speed. Admittedly, only DBB model is running close to its limit using ~70% of clock-cycle for computation.
- the labelling of input and output ports makes following signal paths very difficult
- the use of buses and tags would greatly improve the readability of the diagrams
In short, it appears that these models just haven't taken advantage of any of the modern RCG features and experience to improve efficiency and legibility.

ISCT1 Mad City Labs (MCL) PZT Driver (for POP AIR) Moved 

This Driver was on the south (crane coordinates) end of enclosure roof.  It was moved to the north side.  This required making a new Power cable (Thanks Manny/Fil) & barrel-ed some BNC extensions to the BNC.  I did not touch the DB9 cables, but they are labeled and dangling out of the south wall for now.

Covering ISC/IO Enclosure Holes (this was done yesterday)

Peter K asked me to cover some small holes on the ISCT6 Enclosure.  I went ahead and checked all the enclosures and covered holes with foil tape to the best of my abilities (so some roof panels and some chamber-side panels might have been passed over, but as noted, these are small holes.)

The IMs in HAM2 shift alignment after the HAM2 ISI trips, and as part of my investigation into the alignment shifts, I counted the number of ISI trips in a year.

Interestingly enough, Hugh and I both estimated 20-25 ISI trips in a year, however the number is much higher, at 94.

What I also discovered that in Commissioning Mode, the ISI trips an average of 10 times / month, while during the O1 run, the ISI trips an average of 5 times / month.

Since H1 was not vented, it's expected that the IM alignment shifts will continue through O2, and we can expect 5 times / month while in the science run.

[Sheila, Jenne]

These are numbers pulled from our dP/dTheta measurements from last night (mentioned in alog 27235).  I have gotten the numbers into RIN/theta, since we want to know how much the power fluctuates for a given angular motion of an optic.  The short summary is that the Yarm optics affect the power fluctuation much more significantly than the Xarm optics do, and that the ETMs affect the power more than the ITMs. 

Sum up of 2W results:

We'd like to remeasure these values at different powers - hopefully they're constant.  Of course, these are relative power fluctuations versus angle, so the overall force on the optics will be increasing as we increase the power.

The following table with more detailed results has a crazy-town amount of information, some of which I'm not totally sure what to do with yet.  The difficulty is that since we have ASC loops running, when we dither one test mass, all 4 test masses move.  So.  Here's the gory detail.  All dithers were at 0.51 Hz in pitch to the L2 stage of the test masses. Start times are UTC of 17 May 2016. The values in the table below are at our 0.51 Hz dither freq.  The numbers in the summary table above are the RIN of POP_A_LF versus the angular motion of the optic we were driving at the time.