J. Kissel

In prep for next week's HAM6 vent, I've gathered driven transfer functions of all DOFs of the H1SUSOMC, H1SUSOM1, H1SUSOM2, and H1SUSOM3. As expected, they look identical to what Stuart measured prior to the last time we vented HAM6 (see LHO aLOG 17653). Note, all alignment and ISC control was OFF, so I did not see any of the problems with OM1 that Stuart mentions (and I only learned about those troubles after re-reading Stuart's entry -- too late now to investigate further). Note the models were never tuned and/or fit to measured data for these suspension types, so it's not surprising that resonances don't particularly match up with model.

We'll gather more some quick data in-air before the doors come off next week, and then again right after the doors go on (especially given that we'll have replaced the OMC breadboard). We'll compare against this data set once we're pumped back down.

Data templates have been committed to in:
/ligo/svncommon/SusSVN/sus/trunk/OMCS/H1/OMC/SAGM1/Data/
2016-07-29_1554_H1SUSOMC_WhiteNoise_L_0p2to50Hz.xml
2016-07-29_1554_H1SUSOMC_WhiteNoise_P_0p2to50Hz.xml
2016-07-29_1554_H1SUSOMC_WhiteNoise_R_0p2to50Hz.xml
2016-07-29_1554_H1SUSOMC_WhiteNoise_T_0p2to50Hz.xml
2016-07-29_1554_H1SUSOMC_WhiteNoise_V_0p2to50Hz.xml
2016-07-29_1554_H1SUSOMC_WhiteNoise_Y_0p2to50Hz.xml

/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/OM1/SAGM1/Data/
2016-07-29_1611_H1SUSOM1_M1_WhiteNoise_L_0p2to50Hz.xml
2016-07-29_1611_H1SUSOM1_M1_WhiteNoise_P_0p2to50Hz.xml
2016-07-29_1611_H1SUSOM1_M1_WhiteNoise_Y_0p2to50Hz.xml

/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/OM2/SAGM1/Data/
2016-07-29_1640_H1SUSOM2_M1_WhiteNoise_L_0p2to50Hz.xml
2016-07-29_1640_H1SUSOM2_M1_WhiteNoise_P_0p2to50Hz.xml
2016-07-29_1640_H1SUSOM2_M1_WhiteNoise_Y_0p2to50Hz.xml

/ligo/svncommon/SusSVN/sus/trunk/HTTS/H1/OM3/SAGM1/Data/
2016-07-29_1642_H1SUSOM3_M1_WhiteNoise_L_0p2to50Hz.xml
2016-07-29_1642_H1SUSOM3_M1_WhiteNoise_P_0p2to50Hz.xml
2016-07-29_1642_H1SUSOM3_M1_WhiteNoise_Y_0p2to50Hz.xml
These data were exported in the same location under similar names. 

I was delighted to find that all of the matlab analysis software still works like a charm [thanks Stuart & Arnaud!], specifically, 
/ligo/svncommon/SusSVN/sus/trunk/HTTS/Common/MatlabTools/
plotHTTS_dtttfs_M1.m
plotallhtts_tfs_M1.m

/ligo/svncommon/SusSVN/sus/trunk/OMCS/Common/MatlabTools/
plotOMCS_dtttfs.m
plotallomcs_tfs.m

I'd updated the plotall*.m scripts first to receive all of the measurements Stuart has taken recently of his SUS before adding my new measurements (No I didn't. I forgot, and had to reconcile after). The latest version of those scripts have been committed accordingly.

The OMC alignment servos keep turning on, even though the OMC guardian is paused.  I found that it gets turned on in engage_wfs_centering whenever we do any ASC since it's in a generate states function.  So, I have commented out that line, but we must uncomment it when we have the OMC back and are ready to use it again.  It is currently line 113 in ISC_GEN_STATES.

State of H1:  vent prep, parasitic down-time work, camera crew is here

Details:

• EY BRS is off
• HAM6 HEPI is locked down (ISI is still active)
• EY ion pump power supply tripped this morning - Richard and Gerardo looking into it
• Christine and Karen are in the LVEA cleaning

Currently:

• I'm locking arms green

see also https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=28644

Today I further torqued the RGA analyzer to protective nipple flange that was "gappy" from the factory.  The factory supplied fasteners are an inadequate alloy and limit the factory assembler's ability to achieve the desired "flange-to-flange" joint (it is 2016, why can't they just use silver plated A-286 like the rest of the free world?).  Anyway, I was able to improve the situation and further close this joint using metric wrenches (arghh! again with the "it is 2016...free world") and elbow grease but couldn't go as far as I would have liked.  I again leak tested this joint (7 x 10-9 torr*L/sec baseline) and, again, found it not to be leaking but the real proof will be after it goes through the upcoming bake cycle.  Additionally, I opened the Nitrogen and Krypton isolation valves so as to allow leak testing of their double sided 1.33" CF joints.  No leaks (6 x 10-9 torr*L/sec baseline) here either.  Next up will be to bake everything (will likely start Wednesday, Aug. 3rd during HAM6 vent activities).  

Leaving area with Nitrogen and Krypton isolation valves closed, local turbo off and isolated and leak detector off and decoupled.  

File extensions - .001= 35W path .002=200W

RPN - 35W; no changes worth mentioning.

          200W; noise is higher in the 300Hz-2k range.

FRQ - 35W; seems to hav a higher degree of error correction. Resonances that aren't noticible in recent past scans appear starting at ~7Hz/20Hz and seem to have harmonics out to ~100Hz

         200W; These same resonances mentioned above seem present in this path as well. Last weeks scan by comparison show these resonances propogating out as far as 200Hz

PNT - 35W; This looks much better than last weeks which had 2x and 2y higher than the rest by a factor of two from 1Hz-30Hz.

         200W; This weeks scan looks almost identical to last weeks scan with the outliers being 2x and 2y all the way out to 2K

MSC - 35W; HOM ct/ mode matching looks pretty good with the exception of TEM10 mode which is a bit higher than reference. Significantly better looking scan than last week.

         200W; Mode matching looks a  little sloppy. No change from last week.

Note that there are people in the LVEA during this measurement.

Locked down the HEPI on its hard stops while Isolated.  Positions kept as close as possible.  Here is where it ended up wrt the nominally servo position:

You can also see these on the HEPI CART BIAS medm accessed from the OVERVIEW; look for DC BIAS.

OMC / Vent plans

- OMC is down, we're venting HAM6 and going in next week

- Spare OMC needs some attention before it can be installed - may not be ready by Tuesday

- we may go into HAM6 on Monday to diagnose the situation

- HAM6 is locked down

- cleanrooms around HAM6 being turned on today and will be on all weekend

Tasks:

- CDS - Richard - taking advantage of down time to 

- EY - Kyle wants to bake RGA installed on BSC6, not valved in, next week

- EX - Kyle wants to bake RGA installed on BSC6, not valved in, next week

- PSL - Peter and Jason next Monday and Tuesday - have PSL for alignment and calibrations

- Rich Abbott is here and has a film crew here for today and tomorrow (related to chip manufacturer)

--- in LVEA up to 10AM

- JeffK - getting transfer functions of HAM6 optics for reference

- EY BRS is off - see morning update and Jim's alog from last night

- Hugh - HAM6 guardian is off and needs to stay off - screenshot of HAM6 HEPI and HAM6 ISI attached

State of H1: IMC is locked, guardian in Down state, Hugh in LVEA at HAM6, LVEA is laser safe

Attached: screenshot of current state of BRS, also see Jim's alog 28703

The LVEA is now LASER SAFE.

At this point in time, please do not remove viewport covers, or the tubes connecting
the table enclosure(s) to their relevant viewports.

The pressure change seen in the attached is typical of the Y-arm gauges with PT410 responding first followed by subsequent responses in time as it propagates toward the CS.  Looks like a real change and occurs 15 mins or so after a seismic system change was made at the Y-end (Jim W?) or not.  IP9 has not changed voltage -> Will monitor from home.

Attached are screenshots for the past 7 days optical ever trends for PIT, YAW, and SUM.

This completes FAMIS 4686

Hugh, Evan

Over the course of several locks, we moved the HAM4 HEPI in the y direction by several hundred microns in order to see the interferometer behavior at 2 W with the SRC locked on different fringes.

For a 1.1 mm shift in the HEPI position (i.e., a 2.2 mm shift in the one-way SRC length), there is no discernible trend in the rf sideband buildups or in the DARM pole frequency.

We would like to repeat this test with SR2 offsets as well.

Executive summary: 

* Good news - as expected, the 16-Hz comb due to the OMC length dither is gone (at least at this sensitivity level)
* Bad news - low-frequency 1-Hz combs remain, and some new low-frequency combs & lines have appeared 

Some details:

 I initially looked at 15 hours of 30-minute FScan DELTAL_EXTERNAL SFTs (30 SFTs) generated during ER9 and was aghast at how bad the low-frequency spectrum looked, with a pervasive 0.485308-Hz comb ranging up to its 446th harmonic at 216.4 Hz, but when I exclude the three hours of SFTs when the 2-second ALS- glitches were present, things don't look quite so bad (see figure 1 for a sample without removal and figure 4 with removal). I dewhiten according to the new 6-pole / 6-zero, 0.3 / 30 Hz algorithm.
 The infamous 16-Hz comb due to the OMC length dither tracked down and killed here is gone (at least at this sensitivity level and these SFT statistics). As a result the high-frequency band (up to 2 kHz) is remarkably smooth with only violin modes and sporadic isolated artifacts.
 The 1-Hz comb with 0.5-Hz offset remains pervasive, but other prior 1-Hz or near-1-Hz combs with different offsets (e.g., 0.25 Hz) are not strong.
 On the other hand, there is a new near-1-Hz comb (0.996798-Hz spacing) visible to its 204th harmonic at ~203.3 Hz.
 There is also a new near-2-Hz comb (1.999951-Hz spacing) visible on approximate odd-integer-Hz frequencies, starting from ~9 Hz and visible up to ~175 Hz. This is likely the same 2-Hz comb reported in May by Bryn Pearlstone (which Ansel Neunzert kindly reminded me about today). 
 There is a "new" 56.8406-Hz comb visible to its 11th harmonic at ~625.25 Hz, which in hindsight I can see was buried in the O1 spectrum (I overlooked the pattern and indicated the teeth as isolated lines). This time the pattern was strong enough to jump out at me and to jog my memory that this comb was seen in  H2 1-arm data in 2012 in both the arm feedback channel and a quiet sensor-noise-dominated OSEM channel. This seemed to indicate a DAQ system problem at the time. I can see from O1 NoEMi line lists that this comb is pervasive in ISI, SUS and PEM channels at the corner station and both end stations.
 The old "K" comb-on-comb (0.088425-Hz fine comb attached to teeth of a coarse 76.3235-Hz comb) has more 11 more fine teeth visible on the lowest-frequency coarse-tooth comb.
 The old calibration line at 35.9 Hz has been moved to 35.3 Hz. The new excitation lines at 33.7 and 34.7 Hz are easily visible, but not as strong as the primary calibration lines. I found these changes documented here.
 There are sporadic new isolated lines here and there (indicated in line list - see below)
 There is a "crab-killer" broad bump centered at about 58.6 Hz which degrades sensitivity in the Crab Pulsar band of interest (~59.3 Hz). On the other hand, the whole noise floor is elevated w.r.t. O1, anyway. So it may be premature to worry about the bump.


Figure 1 - spectrum for 50-100 Hz when the 3-hour 2-second-glitches stretch is included (~0.5 Hz lines marked with 'h' for 'half')
Figure 2 - 0-2000 Hz (removing 3-hour bad stretch from here on)
Figure 3 - 20-50 Hz sub-band 
Figure 4 - 50-100 Hz sub-band 
Figure 5 - 100-200 Hz sub-band
Figure 6 - 1300-1400 Hz sub-band (illustration of how clean the high-frequency band is)

Also attached are a larger set of zipped sub-band spectra and a lines list (excluding the bad 3-hour stretch). Note that because the statistics here are two orders of magnitude smaller than used for the full O1 run report, I am not yet removing lines seen then that may yet re-emerge with more accumulated post-O1 data. So many of the line labels in these figures are buried in the noise fuzz for now.

Line label codes in figures:

b - Bounce mode (quad suspension)
r - Roll mode (quad suspension)
Q - Quad violin mode and harmonics
B - Beam splitter violin mode and harmonics
C - Calibration lines
M - Power mains (60 HZ)
O - 1-Hz comb (0.5-Hz offset)
o - weaker 1-Hz and near-1-Hz combs (various offsets, including zero)
H - 99.9989-Hz comb
J - 31.4127 and 31.4149-Hz combs
K - 0.088425-Hz comb-on-comb
t - 1.999951-Hz, 2.07412-Hz and 2.07423-Hz combs
D - 56.8406-Hz comb
x - single line (not all singlets in the vicinity of quad violin modes are marked, given the known upconversion)