[Sheila, Jenne, Cheryl]
We found that many optics' drivealign sliders were in the wrong place after last week's RCG upgrade - these are things that we specifically keep out of the SDF system, since they are often changing by small amounts. But, this means that they aren't kept up to date in the safe and down SDF files. Anyhow, they have been restored, and we were able to lock and align the green arms, and were also able to lock the Xarm in IR for the input align step of initial alignment.
Cheryl will attempt the rest of the alignment sequence, so we have a nice IFO for tomorrow.
Sheila, Jenne, Cheryl
Xarm IR locking was difficult again today, and we made two observations.
We have a more aggresive low pass filter in MC2 M3 than we really need, CLP300. We locked the arm twice sucsesfully with this filter off and CLP500 on instead. screenshots are attached with the digital gain set to 0.15. We didn't add this to the guardian yet, but I think its a good idea (third screenshot attached shows the trial configuration).
We are in no danger of saturating M3, but M2 saturates when we are trying to acquire. This might be the root of some of our troubles accquiring the xarm.
I've tested this new arrangement about 10 times in the last 15 minutes, and it does seem much better than what we had before, so I've put it in the guardian and committed them.
The noise eater was bad in these periods: [17:34, 17:52], [18:10, 18:39] and [19:38, now-ish] UTC, or [10:34, 10:52], [11:10, 11:39], and [12:38, now-ish] local time.
I went to the LVEA and reset it.
This probably doesn't have anything to do with Peter's dark noise measurements, but this might have caused some confusion when he was measuring the intensity noise.
Following on from last week's entry about the power stabilisation photodiodes
https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=27054
It took advantage of the laser being down to measure the output of the photodiodes
when laser was off. The two measurements are quite different. Not just in
level but also spectral shape. The spectrum posted earlier is observed when one
tees the signal off and inputs it into an oscilloscope.
One observation is that the isolated LEMO connectors on the photodiode box
are not isolated from the table surface. Neither are the photodiode housings
within the box.
For what it's worth, attached is the free running RIN of high power laser measured by the first loop diodes (blue, green) and FSS transmission (red) as of now.
Even though Peter and Jason decreased the light on the PDs, I had to increase the diffraction to 15+%, otherwise the PDA and PDB "AC" still rails once in a while and ruin the spectrum.
Also plotted is the dark noise of PDA projected onto RIN. This "dark" spectrum was from last evening when the laser was shut down. Since the only PDA and PDB signals we record on the frame are REL channels (i.e. dewhitened AC divided by DC), I had to look at the dark offset of PDA from last evening:
RIN projection = REL spectrum * dark offset / 2.3V
where 2.3V is the "DC" output when the red, blue and green traces were taken. I couldn't do this to PDB as that guy has almost zero dark offset.
Anyway, at least when the laser was shut down and nobody was in the room, the dark noise looked fine.
Discovered Friday after initial bake cycle that the new calibration leaks (had been closed during bake) were proving to be a significant contamination source when opened, particularly the N2 bottle. This is worrisome since the fill pressure is sub-atmospheric (500 torr) implying that it could have been opened while at atmosphere? I believe that I have been in control of these since new and would not have done this but I can't be sure as they would have been stored with various other cal-leaks until needed-hmm. Anyway, I don't have a suitable replacement yet so I elected to rebake everything with the cal-gas valves open - Nominal 200C with exceptions such as <100C for the cal-gas valves.
Durring the RCG upgrade last week, the automatically generated medm screens were cleaned up. Apparently there were some places (ALS end station overview is one example) where we were pointing to screens in the wrong directory since the ISCEND and ALS models were split. This worked until the directories were cleaned up last week.
I've added macros for alseamodel, alsebmodel, alexmodel, and alseymodel to the isc macros file (userapps/isc/common/medm/isc_macro.txt, iscex_macro.txt, iscey_macro.txt), and edited ALS_ENDSTATION_OVERVIEW.adl to use this. There might be other places we need to change the model we are pointing to.
All of this is in svn.
Before Patrick adds channels for smoothing factor to CP liquid levels (right now only available at LX), I wanted to observe the motion of a few of the LLCVs: CP1 (electric) - some motion (~ +/- 1 mm) CP5 (pneumatic) - lots of motion (more than 1 mm) CP6 (pneumatic) - some motion CP7 (electric) - no noticeable motion (hard to sense even by feeling it) Did not look at CP8 (electric), but its readback is pretty flat. CP4 (pneumatic) is currently in manual mode and CP3 is shimmed. CP2 (pneumatic) was adjusted last week with 99% smoothing function.
Transition Summary: Title: 05/09/2016, Day Shift 15:00 – 23:00 (08:00 – 16:00) All times in UTC (PT) State of H1: IFO unlocked. Work on PSL is ongoing Commissioning: Outgoing Operator: N/A Activity Log: All Times in UTC (PT) 15:00 (08:00) – Start of shift 16:22 (09:22) Peter – Going into PSL to pull inner loop photodiode box (WP #5872) 16:25 (09:25) Kyle – In the LVEA working on RGA 16:40 (09:40) Jason – Going into the H1 PSL enclosure 16:45 (09:45) Kyle – Craning leak detector over the X-Beam manifold 16:57 (09:57) Kyle – Finished craning in LVEA 17:00 (10:00) Bubba – Filling the water tank in the End-Y compressor room 17:20 (10:20) Open gate for people coming to see Ed for Mercury transit 18:00 (11:00) Bubba – Back from End-Y 19:50 (12:50) Jason & Peter – Out of PSL 20:00 (13:00) Dale – High school tour of control room 20:25 (13:25) Corey – Going into Optics Lab 20:45 (13:45) Dave – DAQ restart 20:50 (13:50) Sheila & Jeff – Reset ALS fiber polarization for X and Y 21:45 (14:45) Kyle – Going into the LVEA to check RGA temperatures 22:01 (15:01) Kyle – Out of the LVEA 22:10 (15:10) Peter – Going into the H1 PSL enclosure 22:38 (15:38) Kyle – Going into LVEA to check RGA temperatures 22:45 (15:45) Jason – Going into the H1 PSL enclosure End of Shift Summary: Title: 05/09/2016, Day Shift 15:00 – 23:00 (08:00 – 16:00) All times in UTC (PT) Support: Incoming Operator: Cheryl Shift Detail Summary: Work continues on the PSL and vacuum system. Other groups taking advantage of this time to make updates and upgrades.
Set CP4 to manual mode at 25% LLCV open. Then installed flow meter at exhaust. Will leave as-is for a couple hours to observe changes in LL or exhaust pressure like we saw last Friday (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=27057). The LL spikes may have been driven by the LLCV PID. Switching to manual mode should exploit that variable.
Just switched back to PID. Will leave the flow meter connected overnight.
2:45pm local time 1/2 turn open LLCV bypass valve - took 1:05 min. to overfill CP3.
Trends for last week.
Sheila & Jeff B. - Adjust ALS X and Y fiber polarization
Some more items related to POP X commissioning:
Gain and whitening
I set the analog gain at 39 dB, which is what is required to make the whitening chassis + ADC dominated by the input noise of the whitening chassis at 1 Hz. This might be overkill.
Phasing and quadrature separation
We wanted to check the quadrant phasing on POP X using a laser that can be amplitude modulated at 36 MHz. I used the same ISC laser that Kiwamu and others have used previously on other ISC photodiodes (e.g.: 9630).
Today this laser was putting out 3.4 mW dc. I drove its rf modulation input with −40 dBm at 36.4 MHz, and then tuned the frequency until the beat note showed up in the digital system at around 40 Hz. Assuming Kiwamu's calibration is still correct, this implies a total rf optical power of about 55 µW pk coming out of this laser.
The separation between I and Q for each quadrant was already pretty good (see attachment), and only needed a few degrees of adjustment.
I also wanted to balance the relative phase rotation of the four quadrants by zeroing the phase between I1 and I2, then I1 and I3, and then I1 and I4. However, by physically rotating the orientation of the laser relative to the WFS diode, I found that I could change these relative phases by tens of degrees. So it seems this setup cannot be used to set the quadrant rotations.
The beat note showed up in each quadrant with about 5000 ct pk amplitude (with a 20% spread between the quadrants). Assuming a large fraction of the laser light is falling on the diode, this allows us to estimate the order of magnitude of the gain of each quadrant: it is of order 4×106 ct/W, assuming no analog gain from the whitening chassis, no digital gains, and no whitening.
HPO and ISS are being worked on by PSL team. Work is ongoing and laser status is up and down as the work continues. Did not post various power status in report, due to on going work.
Work plans for next couple of days:
SEI: Jim - running TFs at End Stations
Cheryl – Running TFs on IM during evening shift
SUS: Jeff K. - Working on SUS model changes
ELE: Running cables for access system in the LVEA
Cleaning up cables at both End Stations
VAC: Running E-Net cables for new gauges in LVEA and both End Stations
Continuing to bake out RGA in Vertex
FAC: Beam tube sealing continues
PSL: PD on this weekend's laser WD trip
Continued work on ISS and PMC
Outreach: Dale – Bringing tour through ~ 13:00 to 13:30
It seems like the laser shut down at around 11 pm local time friday night after being on for about 14 hours. Attached is a screenshot of the laser medm screen as it look now, and some trends, the first is 4 seconds around the time it shut down (2016-05-07 4:46:56 UTC). Of the channels I looked at the HPO watchdog (PSL-OSC_PWRDOGON?) and the LRA seem to be the first to go. The third screenshot shows the power outputs over the 14 hours the laser was on, along with the humidity trend. The humitidty looked alarming at first, but the last attachment shows a 10 day trend where the humidity seems to fluctuate this much and more.
Looks like the NPRO shut down too, for whatever reason - which is not obvious to me.