The main story of the day is related to the non stationary low frequency noise first seen early in the morning. It seems to come from CHARD noise, which could be coupling to DARM more now because of a change in alignment.   

• Once we were stable at 24 Watts this afternoon, we didn't see the terrible low frequency noise that was seen in the early morning (at least it was not as bad).  
• Jenne and I worked a bit more on the CHARD loops, adding 23 Watt boosts, a lead filter that gave us some phase to make cut offs.  The first attached screen shot is a comparison of CHARD PIT at 3 Watts, and at 24 Watts before and after the changes.  Jenne has similar measurements for yaw.
• The terrible low frequency noise came back.  
• We undid all of the CHARD changes we made yesterday and this afternoon(keeping only the leads and cut offs) .  The terrible low frequency noise did get better, although some extra non stationary low frequency noise remains below 50 Hz.  The non statinary noise was reduced when we did this, although we still had some excess non stationary noise below 50 Hz, and coherence with CHARD.  We did another round of on/off test to be sure CHARD was involved.  
• We decided to check on alignments that we thought moved durring monday's PZT power off and PSL temperature excursions.  We could see that we had moved on IM4 trans after monday, so in full lock we moved IM3 to bring ourselves back to the old location on IM4 trans.  
• We then redid inital alingment, carefully, and relocked, using the low bandwidth CHARD loops and our new cutoffs.  After this the noise does seem better, but there is still excess noise that is non stationary.  

A few ideas for next steps:

• see if we can find a better CHARD sensor.  Do we need to use trans mon QPDs or is there a way to find a better SNR on the refl WFS?
• can we do a better job with A2L?
• We could try to change our alignment to see if we can reduce this noise.
• DHARD resonant gain for the 0.46 Hz instability.  This instability only seems to come up when we have a bad alignment, but a little more gain can probably help us avoid it. 

We also worked on a few other things today...

• Between Evan and I we reverted the phase of the 45 WFS to what they were a week ago (before TCS tuning)
• Gabriele and I saw this morning that we think that a SRC1 YAW input matrix of -3 for AS A 36 I and no signal from AS B is good.  We watched all of the AS 36 Yaw signals as we powered up to 17 Watts, and saw that AS B sees something that drifts as we power up.  When we removed AS B from the input matrix, the AS 90 power increased.  
• The SRC2 Yaw loop was painfully slow (several minutes reaction time).  It now has a factor of 2 more gain (-40 is fm gain now, it was -20 before).  This is in gaurdian. 
• Gabriele had a look at doing frequency dependent A2L for ETMX.  We have reverted it for now, but it seemed promising. 
• Our locks today seem quite stable, we have been loosing lock by making mistakes, and when we have a combination of driven measurements and PEM injections.  
• ETMY ESD LP had been turned off at some point, most likely unintentionally.  It's on again, and now monitored in SDF.  We also turned the PUM coil drivers back to their low noise state.  We needed more range for DHARD when the roll mode was rung up very badly last week (because of DOWN not runnning for extended of periods of time twice.)  These were a mixed bag of monitored and not in SDF, I think I've set them all to monitored now, with the requested state as 3.  However, this gets over written by the gaurdian.  
• I had put offloading of full lock ASC in the normal guardian path, but this seemed to make the DRMI alingments for relocking worse (possibly because the full lock ASC is compensating for some wire heating).  So it is now removed from the normal path, but can be choosen as an option after transitioning to DC readout.  

I ran Hang's latest A2L script (see aLog 20013), after the realignment work that was done tonight (Sheila is writing up her entry as I type). 

We stil have excess noise at low frequency, but maybe there's a bit less than when I started the script?  The noise we're seeing is totally non-stationary, so it's hard to say.  Certainly the A2L didn't eliminate it.

Dan, Nutsinee

Tonight we identified and damped more ITM first harmonics.

They will be added to the violin wikipage.

All Times in UTC

• Beginning of the shift:  Various commissioning activities going on
• 23:29 (UTC) (16:29PT):  Violin work (Nutsinee)
• 0:45 (17:45):  PEM injection work in LVEA (Robert)
• 5:30 (22:30):  ITMy Roll mode damped
• Did some work learning how to run current lockloss tools.  Added some info about the lockloss tool to the Useful Scripts wiki.

(Dan, Corey)

Around 5:30UTC (22:50PT), Dan noticed a rung up roll mode on DARM spectrum, and from the Bounce/Roll monitor, the culprit was ITMy. 

Brought up the bounceroll.stp StripTool from the Ops Template & could see ITMroll channel high.  From the ITMy SUS screen, opened the DARM BR DAMP filter bank screen.

Initial Values:  -60degrees & a gain of +40.

New Values:  +60degrees & a gain of -80.

This took care of ITMy, and should be fine for this current lock.  Whether we want to keep ITMy like this remains to be seen.  Should see how we look after a few locks.

After the PSL temperature adventure on monday afternoon, it seems as though the PMC alignment shifted.  We now get less transmitted power, although the sum of refl and trans has not changed much. 

FRS 3247

The h1hwinj0 computer has been renamed to h1hwinj2. 

Scott L. Ed P. Rodney H.

8/11/15
After filling the water tank, the crew moved the fans and re-strung the lights. 45 meters of tube and bellows were cleaned ending at station HSW-2-012. Cleaning results posted here.

8/12/15
60.6 meters of tube and bellows cleaned ending at station HSW-2-009. 

Sheila, Elli

Summary:

Yesterday morning durng maintenance we went out quickly to measure the beam parameter ar AS-Air.   IThe beam waist is 3.7e-4 (1e-4) m at the AS_Air camera.  The fit of the beam divergence is pretty bad, we were hurrying to get done quickly and I didn't take enough data points to get a good fit for the beam divergence.  Using measured waist size and the (very poor) fit of beam divergence, the beam parameter at the AS_AIR camera is calculated to be 0.14+0.22i in the vertical axis and 0.16+0.29i in the horizontal axis.  UPDATE:  Today during the Earthquake at lunchtime I went out and took some more measurement points.  I am fitting these new points at the moment, and hopefully they will improve this measurement.

Details:

We used a straight shot through corner station with PRM, ITMX, SRM misaligned.  We placed a flipper mirror 0.434m upstream of the AS_Air camera, which sends the AS-Air beam across ISCT6 where we used a Thorlabs BP-104 slit scanning beam profiler to measure the beam profile at 5 locations (see optical layout diagram).  This beam scanner is mounted on its side, so that Y is the horizontal axis and X is the vertical axis.  The laser power was turned up to 24W to get enough light on Thorlabs beamscan to take a measurment (and the backgorund noise was still high at 24W).

The background noise was to high for the beam profiler to automatically fit beam waist, so we saved the beam shape in the x and y axes and fitted a waist size to these beam profiles after the measurement was over.  Puzzlingly, the maximum intensaity in the X and the Y directions is not the same.The fit of the gaussian beam in x and y is good.  Then plotted beam radius vsd distance to fit the waist location and size with a hyperbolic function.  There aren't enough points/too much error in each point to get a satisfying fit.  I have attached a fit which looks kind of reasonable, but really there is too much variation in the points to call this a good fit .(See picture of alternative fit which is almost as good, and very different.)  So the Beam waist location/size can't be pinned down using this meaurement.  This measurement could be inproved by taking more data points.

The ALS end station shutters have temporarily been commented out of the guardian. (They will no longer close, even in the shuttered state).  The goal is to have green light locked in the arms while we are at a good sensitivty, with the idea that this could possibily be helpfull for determining if some of the glitches we see are due to dust.  ( alogs 20395 20355 20328 )

We had originally added the closing of the shutters since we heard that it improved the noise at LLO, even though we saw no evidence that it improved our noise here.  After a few weeks of engineering run we should revert this change.

   Reset the dust monitor alarm levels for the LVEA, VEAs, and PSL from the tighter levels associated with the June vents to the levels for the O1 environment. The current values are:

The Diode Room and Optics Lab alarm levels will be adjusted when I can get confirmation of their particle level requirements

I have updated the correction filter for the dtt DARM spectra that are projected in the wall and screens in the control room. I hope Evan will like it.

This does not affect the CAL-CS or GDS calibrations. This is only for display purpose in diaggui.

[The DARM spectra]

Here is a comparison of the newly corrected and previous DARM spectra.

As shown in the attached screenshot, the high frequency excess wing that has been shown above 3 kHz is now gone. The noise level at around 7 kHz now seems a bit too low compared with the f-shaped GWINC curve (shown in green). This maybe a real calibration error because I have applied the best and latest knowledge about the sensing chain for correcting the spectrum.

The correction filter is made by a matlab script:

/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER8/H1/Scripts/ControlRoomCalib/H1DARM_FOM_correction.m

This script creates a text file which contains the correction filter in [freq, dBmag, phasedeg] format from 1 Hz to 7444 Hz. The text file can be found at

/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER8/H1/Scripts/ControlRoomCalib/DARM_FOM_calibration.dat

Both script and text files are checked in to the svn. Also I updated the latest FOM dtt template, H1_DARM_FOM_20150722.xml so that it now uses the new correction filter.

[Corrections newly included]

Here is a list of what I newly included.

• Analog anti-aliasing filter
  • See this plot from alog 17951
• Unconmpensated OMC DCPD poles
  • See this plot from alog 18037
• True zpk([355], []) cavity pole, instead of zpk([355], [7000]) in the IIR filter
  • See some discussion in G1501013

Note that the previous correction was made only from the IOP down sampling filter and the numerical whitening zpk([1,1,1,1,1], [100,100,100,100,100]) which are still included in the new correction.

I took a look at the scattering noise we see in all lock since last night .

I computed the band-limited RMS between 20 ans 120 Hz, and this is a good indicator of the scattering noise level. Then I looked at correlations with all suspension motions (using M0 and M1 signals, as Keita did for the OMC).

So I'm able to reconstruct the noise variation over time, using a linear combination of all the suspension signals and their squared values. However, I'm not able to pick point one single mirror which is moving more, as shown in the ranking of the most important channels for the BLRMS reconstruction.

I compared the suspension motion spectra from tonight (GPS 1123422219) and few days ago (GPS 1123077617). The most relevant difference is that all test masses YAW motion have now a large bump at 3 Hz. ITMY also has large lines at 0.45 and 0.63 Hz. Finally ETMY pitch shows a large line at 6 Hz and some excess noise above that frequency.

Not sure if all of this is really relevant...

   Checked the End-Y building and found no apparent problems with doors, doors seals, or penetrations into the building. Given general air quality (high winds, smoke, dust, and no rain) over the past few of weeks, spikes or upward trends in counts would not be surprising.

   At End-Y, there were 17 spikes over 1000 0.5-micron particles over the last 60-days. The 60-day trends do not show any upward slope. Over the last 24 hours, there were seven spikes over 1000 0.5-micron particle. There were seven recorded entries into End-Y during Tuesday’s maintenance window, at least one where the roll-up door open between receiving and the VEA was open. The 0.5-micron plot shows a sharp spike during the maintenance window, which trends upward, then drops. There is a second sharp spike last night/this morning. There is some coloration with the wind speeds during this period. The air filtration system takes several hours to clean the air within the VEA.

   The alarm level were set much tighter during the vent activities when chambers were open. They will be relaxed to the class-10000 levels for O1.       

Several things to keep in mind:

1). The 227b monitor at End-Y is archaic and not entirely dependable. It is slated for replacement.

2). The 227b samples for 20 seconds then multiples the sample by 30 to correct it to the standard 0.1CFM sample rate. Sample times of less than 60 seconds are known to be less reliable.

3). The VEAs are required to maintain a clean-100000 level. The dust monitors are set to alarm at less than a clean-10000 level. The counts recorded are well below these levels.

4). The reference particle size for a class designation is 0.5-microns not 0.3-microns. The 0.3 particle size counts tend to be 10x those of the 0.5 particle.

5). Based upon particle and air temperature trends the internal air filtration system is working properly when the doors are closed.    

End-Y Measured Particle Counts 08:09 through 08:23 08/12/015

DetChar has requested we generate the front end model ADC channel lists. This is a new RCG feature in which all the ADC channels a model uses are listed along with the name and type of the first connected part in the simulink model. This feature is in the trunk release of RCG and not available in RCG-2.9.6. To generate the lists I performed a "make -i World" in the trunk build area (taking care to save the H1.ipc file before and ensuring it was not modified). I then copied the files from their build area into the location these files will eventually occupy (/opt/rtcds/lho/h1/chans/adc/). I then copied these files over to the exports area of the web server for offsite access:

https://lhocds.ligo-wa.caltech.edu/exports/adc/adclist_11aug2015/

Note that the ADC numbering always starts from zero and is not necessarily the physical card number. For example, h1tcscs.mdl has two adc parts (called ADC0 and ADC1), which are card_num 2 and 3 (the third and fourth ADCs in the chassis). In the h1tcscs_adclist.txt file the cards are referenced as 0 and 1.

Some random commissioning tasks from tonight:

LSC rephasing

In full lock, the phases of POP9 and POP45 were adjusted to minimize the appearance of PRCL in POP9Q and the appearance of SRCL in POP45Q. Then the input matrix element for POP9I→SRCL was tuned to minimize the appearance of a PRCL excitation in the SRCL error signal. New settings attached.

We should take a sensing matrix measurement sometime soon.

LSC OLTFs

I took OLTFs of PRCL, MICH, and SRCL. The data are attached.

[I also did some noise injections into CARM for frequency budgeting purposes. Those are attached too.]

Front-end LSC triggering

Jamie and I started this a few weeks ago, and now it is completed.

There are occasions when the DOWN state of the ISC_LOCK guardian (which, among other things, turns off feedback to the suspensions) is not run immediately after a lockloss (e.g., because the guardian is paused or in manual mode). Therefore, Jamie and I set up the LSC trigger matrix so that PRCL, MICH, SRCL, DARM, and MCL are turned off if POP DC goes below 100 normalized counts. This is set in the DRMI_ON_POP state.

CARM gain redistribution in the Guardian

The state REFL_IN_VACUO now redistributes the CARM gain slightly in order to improve the noise performance of the CARM loop. This state has not been tested and has been left commented out.

V. Sandberg & R. McCarthy

The SUS-TMSX OSEM Satellite Box was driving a ~2kHz oscillation on its DC power line again. (See https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=20428) This time we replaced the satellite box.  Verified that H1:SUS-TMSX_M1_OSEMINF_RT_IN1 and H1:SUS-TMSX_M1_OSEMINF_SD_IN1 were behaving themselves.  Work was done during the interval 18:00 - 18:45 UTC (11:00am - 11:45am PDT).

Apologie: I failed to follow my own rules and neglected to notify the operator on duty before we left and changed out the satellite box at End X.  Shame and humiliation duly noted.  :-(  Fortunately, no damage was done.

Sudarshan, Gabriele

Today when the IFO was locked in low noise, we could see the 300-400 Hz peaks in the sensitivity again. Those are know to be due beam jitter caused by the PSL periscope.

We looked into the performance of the ISS second loop, which was closed at the time. The first strange thing that we can't understand is that both the in-loop and out-of-loop signals are dominated by a flat  noise background at a level of 1e-8 /rHz. We would expect the out-of-loop to be at this level, but the in-loop should be squeezed down by the larg loop gain.

We changed the ISS gain, anmd discovered that if we turned down the gain at the minimun (-26-20 dB with respect to nominal), and disengage both boost and integrator, the in and out of loop ISS signals got worse, but the sensitivity got better at the 300-400 Hz peaks. So out guess is that beam jitter on the ISS array is actually causing an excess sensing noise on the ISS diodes, which is then re-injected into the laser beam as real intensity noise when the ISS second loop is closed with high gain.

We tried briefly to optimize the centering of the beam on the ISS array. We couldn't find any spot better than the initial one in terms of power on the diodes. One possible strategy would be to move the beam into the ISS array with the IFO in full lock, and use the coupling of a PZT jitter line to the sensitivity as a figure of merit.