Since we are looking at ASC we reverted the AS36 B phases which were adjusted durring the day. The settings are attached (the setpoints were the AS90 team phasings) just in case people want a record.
Jenne, Hang
We tried more WFS phasing with AS 90 as our centering loop today.
## AS B 36 I:
We first looked at AS B 36 I and tried to use it for SRM sensing. We excited a length signal first and phased each segment s.t. the signal showed up in I phase, to fix the relative phase between the segments. We found that the demod phase of segs. 3 & 4 was 90 deg diff than that of segs. 1 & 2. Then we drive SRM in pitch (yaw) and rotated the demod phase for all quardrants together to optimize the angular signal in I phase. However, we could not close the SRC loop even after re-phasing. By applying a static misalignment to SRM, we found the AS 36 B I responsed only to one direction but not the other. No clue why this was the case yet.
## AS A 36:
We then decided to use only AS A 36, with Q phase for BS and I for SRM. The demod. phase was set by maximizing BS angluar signal in Q (w/ 90 centering, DRMI locked).
The new (old) demod phase for the 4 quardrants were:
-165 (-140); -145 (-140); -145 (-140); -135 (-140)
At this config., for BS, the Q signal was factor ~ 10 of the I signal, and for SRM, the I signal was factor ~3 of Q.
## Difficulties w/ locking the IFO:
After that we tried to go further in the locking sequence, but kept losing lock at RF_DARM/DHARD_WFS.
We first noticed that the DARM gain at RF_DARM was too large for the new config. We set it to 400 instead of increasing to 1000. Also the DHARD pit & yaw gains were too high. We decreased it by a factor of 10 and saw some oscillation at 15 Hz when offloading was almost done. Then we reverted all settings and handed the IFO to noise-hunting team.
## Things to do:
Rephase the 90 centering WFS. The last time we did it we did not open the MICH ASC loop. Then recheck all other WFS' phasing again. If we still have trouble locking at the DHARD_WFS, stage, we may further decrease the DHARD pit/yaw gains by another factor of ~4ish. We may also just commented out the new offloading gains.
I updated the TCS IFO model/simulation page. The major changes and additions are summarized below:
OPTIC LENS/ROC model (left side of screen):
IFO SIMULATOR:
This is a set of calculations of interferometer values that are dependent on ROC and ITM lenses
The MEDM screen is being (slowly) updated to illustrate these parts
SITEMAP > TCS > MASTER > SIMULATION
Plotting the cross-correlated DARM noise (band 5) and LEVA temperature on the same plot doesn't show any obvious relationship. The .fig is included in case someone has a good idea of how to use this data.
This analysis has been inspired by the recent investigations on the L1 noise , that shows some correlation of DARM variations vs LVEA temperature. By superimposing the current best L1 curve and the best H1 curve from O1 (see plot), one can see that the noise in the L1 bucket seems to have more "scattering looking" peaks (which can be modulated by temperature-induced alignment variations), while the H1 noise less so. The noise at high frequency is notably lower in L1, mostly due to the higher cavity pole frequency.
I have extended Matt's previous analysis to the entire O1. In addition, I added another interesting channel, the vertical sensor of the top stage of ITMY. Here is the result.
I went through trend of some interesting channels where I was looking for signals showing similar variation to the band limited rms of the cross spectra. I came across ITMs' top stage vertical monitors and found them showing two relatively big bumps (actually dips in the raw signals) which seemingly match the ones in the band limited rms on Dec 2nd and Dec 29th. However, even through they look like showing a good agreement in the last half of the O1 period, the first half does not show an obvious correlation. Does this mean that the modulation mechanism of the noise level changed in the middle of the run and somehow noise level became sensitive to vertical displacement of ITMs or in-chamber temperature ?
For completeness, I have looked at other vertical monitors. Here is the result. They all show qualitatively the same behavior more or less. The fig file can be found on a server.
Carlos, Dave:
The /ligo file system filled up this morning. Carlos did an emergency move of /ligo/backups/alog over to the ops-home disk. Later we built a file system on a spare 2TB disk Carlos had installed on cdsfs0 and we moved the Guardian log files backup directory over to it. This freed up 112GB of disk space. Along with other cleanup work /ligo currently has 143GB of disk available. We hope this carries us through to the install of the new cdsfs0 NFS server scheduled for Tuesday 8th.
Day Shift 16:00-23:59UTC (08:00-16:00PT)
State of H1: DRMI lock for Jenne
Shift Summary:
Site Activities:
- 19:30 Kyle - LVEA to survey for upgrade
- 19:45 Kyle - out of LVEA
- 21:27 Corey - optics lab
- 21:15 Ed - LVEA to reset PSL watchdog
- 21:25 Ed - out of PSL
Locking / Initial Alignment:
- locking X arm in red was very fast, and had good power
- ITMY needed more of an offset during SRC alignment
- PRMI needed to adjust BS for DRMI
- DRMI is well aligned and relocking quickly for the last 2-3 hours of the shift
Control Room:
- Video0 froze, now fixed after a reboot
- Video4 had the wrong striptool displayed, now fixed
ITMY mis-alignment issue tracked down to offset, now fixed.
ITMY drivealign_P2L_gain change from 1.05 to 0.6 accepted after the OK by Sheila, had been 0.6 for at least 10 days.
The Front End watchdog reset takes place in the LASER Diode Room, not in the LVEA/PSL enclosure. :)
I've been slowly trying to get stuff figured out for testing a wind fence set up at LHO, and am getting ready to try to set something up. I'll summarize where I think things are here.
Currently, I want to try a small, cheap wind fence at EX, mostly to explore how effective screens are at slowing wind, effects on ground motion and tumbleweed build up. The fence would be a couple of 4x4-ish 12-15 foot posts and some fine polymer netting like that used around tennis courts, gardens and the like. It may be necessary to add guy lines, as well. In addition to the fence, Richard has said he will help me get an STS buried at EX, similar to Robert's set up at EY, and we are ordering 3 anemometers with stand alone data collection so no changes need to be made to CDS for this. I think this set up will allow me to look at a few of the concerns that people have brought up. So far the concerns I've heard are:
1. Increased ground motion. Fences slow wind by applying a force to the airstream, this is transmitted to the ground and produces increased tilt and other high frequency motion. I think the tilt can be addressed by placing the fence some few tens of meters from the building, per Robert's measurements of building tilt. Higher frequency motion can hopefully be addressed by design of the fence support structure, but we'll have to see how bad the motion is.
2. Similarly, the fence could make airflow more turbulent. I suspect that airflow at the building level is probably turbulent anyway. Hopefully, a well designed fence push turbulent flows around the building, while slowing most of the air makes it through.
3. Tumbleweed build up. Anything that blocks the wind will gather tumbleweeds around here, which could make a fence a fire hazard and maintenance issue. This could be addressed by leaving a gap at the bottom. The airflow below a few feet probably isn't a significant source of problems for us, but I don't know how big this gap would need to be. I also plan on using a mesh fine enough that tumbleweeds won't stick to the fence very easily. Industrial fences are flame resistant, and won't ignite on their own.
4. Wind damage. We have seen winds above 100 mph during a storm, this would create very high loads on any fence. I haven't been able to figure out how to calculate wind loads on a permeable wall yet, but Civil Engineers have building codes dealing with this. For my test, I'm trying to get some idea of the loads involved with moderatewind, and just making the fence so that the mesh will tear free in a way that won't damage the EX building if the wind gets too bad. Industrial fences are designed to stand similar wind loads, and their screens are held in place with replaceable break-away clips to prevent damage.
5. Cost/size. BrianL talked to a company that makes industrial fences a few months ago. The ball park figure for a 40 x 200 foot fence was about $250,000. That was a first pass at a price and the company had some suggestions at how to cut down on the cost. This price also needs to be weighed against the 10-15 % of down time we have due to wind. Something of that size would also probably have to be approved by the DOE. It's also unclear if we would have to completely surround each endstation, or if we could get away with less coverage. Probably, we don't need to "protect" EY along the X-axis, or EX along the Y-axis.
Comments, criticism, praise are all welcome.
Comments;
Any break away components will need to be constrained so the EPA doesn't come after us for polluting the desert. I suggest that even a temporary test fence be built to withstand any expected wind/snow/tumbleweed loads.
Be aware that any wind speed and direction measurements are likely influenced by ground effects until you are well above the ground and nearby obstructions - say 25- 50 feet???
Thanks John. The ones I saw advertised had a cable top and bottom which suspended the wind fabric. The top attachments from the fabric to the cable were "permanent" and the attachments to the lower cable were the break-away. This should allow it to yield to the wind load, but to keep it from blowing away and causing more trouble.
Along the same lines of earlier investigations into DARM noise fluctuations, I checked the "high frequency" (1-100mHz) spectrum of the DARM RMS in 2 bands between 80 and 100Hz. The fluctuations in these BLRMSs are fairly featureless, though there appear to be small peaks at 30 and 70mHz (see plot).
The code used to generate these plots is:
gwd = GWData;
data7 = gwd.fetch('26 Dec 2015 8:00:00', 3*60*60, 'H1:SUS-ETMX_L2_DAMP_MODE7_RMSLP_OUT16', 'mDV');
dd7 = GWFilt.detrend(data7.data);
fs = data7.rate; tfft = 256;
[p7, ff] = pwelch(dd7, hann(fs * tfft), [], fs * tfft, fs);
data8 = gwd.fetch('26 Dec 2015 8:00:00', 3*60*60, 'H1:SUS-ETMX_L2_DAMP_MODE8_RMSLP_OUT16', 'mDV');
dd8 = GWFilt.detrend(data7.data);
[p8, ff] = pwelch(dd8, hann(fs * tfft), [], fs * tfft, fs);
loglog(ff, [p7, p8]); axis([0.005, 0.2, 1e-4 1e-2]); grid on
title('Flucutations in DARM noise (Boxing Day 2015)')
legend('80-100Hz band', '100-120Hz band')
xlabel('frequency [Hz]')
ylabel('Power spectrum of variations')
The watchdog was reset at 13:22PST as per FAMIS http:// https://ligo-wa.accruent.net/LB_Request_Update.asp?RequestID=3587.
I took advantage of the the earthquake and the higher winds this morning and went to test out a new PSL node. Much of the code was taken from LLO's PSL guardian, but I tweaked it for our uses and added a few things that they didn't have. After I created the node, I could not get "guardctrl medm" to pop up a medm for the node. (shot of the error attached) In the interest in time, I continued just using the the log and other guardctrl commands. This is much more awkward that I expected and slowed me down quite a bit. After sorting through the few syntax errors, bringing the power up and down, and searching for home, I have some notes and will work on a few issues I found. Overall, it went well and it should, hopefully, be usable very soon.
I stoped and destroyed the node when I was done, I will recreate it next chance I get to test it (whenever that may be).
Completely spaced and did not use "guardmedm". This would have worked for what I needed.
Site activities:
- 17:16UTC Kyle and Gerardo - at EX and door X2-8 to work on cable for annulus ion pump
H1 Update:
- 17:53UTC all ISI platforms returned to nominal isolation
Ex work on hold until the road is cleared of tumbleweeds.
- HEPIs that tripped: HAM1, ETMX (BSC9)
- ISIs that tripped: all ISIs
- oprics that tripped: BS, PR2 (full trip), SR2 (only upper two stages), and MC1(only upper two stages)
- Hugh and Jim were here early, and have ISIs in Damped, and HEPIs in Robust_Damped
- 0.03-0.1Hz ground motion is typically around 0.05um/s, and is currently 0.5um/s
- useism (0.1-0.3Hz ground motion) is at 0.5um/s
Current H1 Status:
- guardian issues being worked on
- too much ground motion to lock
I'm leaving conlog-test-master running and connected to the same channels as h1conlog1-master.
(Chandra, Gerardo and Kyle)
Regenerated NEG pump with the aid of an aux cart.
Valved out NEG pump from X-End, then started regeneration of NEG pump ~19:00 utc.
2 hours later heating was complete, waited for temperature to drop down, valved in NEG pump to X-End volume at 21:45 utc and @ 92 deg C.
Pressure plots attached.
-Chandra
Finished adding Caps to the Negative regulator per latest dwg. Today we completed the ITMx,ITMy,BS, and all of Ham5 and Ham6 Suspensions. Also verified and corrected were needed Ham2 optics. This should stem any oscillations caused by the long cables from the SAT amp side.
I've verified with Richard that this concludes the H1 SatAmp upgrade as per Integration Issue 1129, DCN E1100767, and G1100856. Nice work gents! Stay tuned for a systematic check of how-and-if it has improved the high frequency oscillations this upgrade was intended to fix.
IM2 position is now oscillating by 5urad in pitch and yaw after satellite module fix on Feb. 23.
Three plots attached:
That Sat amp doesn't qualify as fixed at this point. The modification is not currently installed. See Richard McCarthy for details.
3/1/2016 The modification has been added.
