Matlab TFs are set to run on HAM2 suspensions overnight as follows:-  

- MC1 (HSTS) M1-M1 undamped TFs
- MC1 (HSTS) M2-M2 undamped TFs
- MC1 (HSTS) M3-M3 undamped TFs

- MC3 (HSTS) M1-M1 undamped TFs
- MC3 (HSTS) M2-M2 undamped TFs
- MC3 (HSTS) M3-M3 undamped TFs

Starting now, and when complete the measurement status will revert to OFF and damping loops will be restored to the ON state.

n.b. all stages of the above suspensions have been configured to Coil Driver BIO state 1 to try and limit any DAC saturations.

These measurements have been initiated from the opsws2 workstation.

Mitchell R, Mike V, Travis S

Today the ITMY ACB suspension and box assemblies were installed in BSC1. There is good clearance with respect to the ITMY suspension.

Pushers and clamps are installed in preparation for alignment work to commence on Monday.

The photodiode cable is still to be connected followed by a functionality check by Richard M.

The full payload is not in place; masses currently at clean and bake will be installed Monday, followed by a short period of balancing.

Attached is a photo of the installed baffle, along with a bonus shot of a happy Mitch.

8:15-8:45 Morning Meeting
8:50-11:30 Heading into the LVEA to continue with HAM2/3 work – Matt/Jeremy
8:55-11:30 Contamination & Control work in LVEA - Jeff B
8:59-12:00 Going to End Y to work on illuminator – Aaron
9:15-12:00 Working on Optics Lab/Laser ON – Nathan
9:35-11:24 Locking/ Unlocking suspension in LVEA (BSC1 & BSC3) – Travis
9:39-11:24 Heading into the LVEA to work on ACB – Mitchell/Mike V.
9:52-12:18 Stage Viewport Preparation in LVEA – Gerardo
10:20-12:18 Joining Gerardo in the LVEA for Electric Field measurements – M. Laundry  
10:22-11:30 HAM 2 testing in LVEA – Stuart/Arnaud
10:24 - Restarting h1odex model - Dave 
12:13- 14:50 Heading back to the LVEA – Matt/Jeff B/Jeremy/Apollo
12:17- 14:50 Heading back to the LVEA – Stuart/Arnaud
12:43-     Going to End X to work on illuminator – Aaron
13:12-13:56 Working at End Y – Karen
13:18-     Replacing BSC2 ISI chassis in Electronics room – Filiberto
13:40-LVEA transitioning to Laser Hazard – Richard
14:21-12:18 Back to the LVEA for Electric Field measurements – Gerardo/M. Laundry  
14:23- LVEA transitioning back to Laser SAFE – Richard
14:37- 15:40 Returning to the LVEA to work on ACB – Mitchell/Mike V.

model restarts logged for Thu 24/Jul/2014
2014_07_24 05:18 h1fw0

unexpected restart of h1fw0

Summary: Eight years of wind data at 3 LHO stations were analyzed. Fifteen percent of hours had wind speeds exceeding 10 m/s, the speed at which displacement and tilt from wind start to significantly increase the seismometer signals. Nearly 25% of hours in April, the month with the highest average wind speed, have winds exceeding 10 m/s. Data are also shown for individual stations; readings for EY are the highest.

Introduction: The analysis of wind data is important because wind speeds over 10 m/s increase ground motion and thus affect interferometer performance. This increase in ground motion is caused by wind interacting with the topology of the site and, most importantly, the surfaces of buildings. In addition to producing displacements, wind blowing on the buildings can tilt them, which can produce spurious acceleration signals from seismometers.

Methods: Eight years of data between 2004 and 2012 were analyzed for patterns across the years. The data was extracted from DataViewer for the Corner Station (CS), End Station X (EX), and End Station Y (EY). The "Maximum Channel" was selected of the "Hourly Trend" setting within DataViewer. This time period was selected because it was not missing more than 58 days of data at a single time in the series and only a total of 218.7 days were missing from the entire data source. This amounted to about 8% of the data missing from the entire data set. The data was considered missing if DataViewer did not provide it.

Results: The first figure shows that 15% of the hours in the 8 years analyzed exceeded 10 m/s, which significantly increases ground motion. The second figure shows that, during each of the spring months, the wind was greater than 10 m/s in more than 15% of the hours, peaking at 24% in April. The third figure shows that the average hourly maximum wind speed varied the most from year-to-year in the month of February. The fourth figure includes statistics for the individual stations. Averages for EY are higher than for other stations. For example, 27% of April hours exceed 10 m/s at EY while the average for all stations was 24%.

Margarita Vidrio, Robert Schofield

Jeremy B, Stuart A, Jeff K, Arnaud, Jeff B, Matt H, Apollo, Richard M

Success....HAM2 closed up :-)

Quick rundown of events. 

Entering HAM2 straight after doing door work on HAM3 and the particle counts were zero. We had some troubles with PRM showing signs of rubbing overnight so we looked at this first. I didnt find anything glaring but saw a couple stops kinda close. We backed these off ran another set of TFs and got a clean bill of health. Then to save time later we centered all ther OSEMs on all four suspensions on all stages. After this I locked all four HXTs's to get ready for FC pull

Jeff B went in and did a quick last wipe down, put in wafer and monitor optic, removed optics/wafers that were still in chamber, etc. We were all straged to pull FC but couldnt get low particle counts. People were working in BSC's so asked the to stand down to let the particle counts drop. 

After a quick lunch to let the particle counts settle, it was all systems go. On the way out we bumped into Mike Landry et. al. who had been doing tests with the large optics/top gun. I am sure he will write a report on his work but he indicated it took ~9mins for the fields to drop. Thus we decided we should blow the smaller optics for 5mins continuously with the top gun after FC pulled. As I was worried about the pony sized bottles running out we dragged a large cylinder out there for the top gun. 

Particle counts showed us good to go and so we pulled PR3, then MC1 then PRM FC. I went for MC1 now due to the awkwardness of having to unlock that suspension and how have to get on the table to do so. And I didnt want to do this with a half unlocked ISI. I inspected each optic for particulate and Arnaud/Stuart have a log of what I saw (which they will post). We also pulled the FC on the moitor optic. After I reminded myself about 50 times about it :-). We actually had to pull FC twice on it as after I pulled the outer layer, we saw there was still FC on the backside, so had to remove optic to pull backside FC and put optic back. Afte unlocking those three suspensions, TFs were taken on all three by Jeff K/Arnaus and given the all clear. Once the all clear given, the ISI was unlocked on east side and door went on. 

Whilst door being put on on east side I pulled the FC on the MC1 suspension (particle counts were low), and unlocked the suspension. We found we had to change some of the OSEM positions on the three stages.  TF's were taken on this suspension and given the all clear. Whilst TFs were being taken, Richard M transitioned us to laser hazard, and I visually inspected the ISS array cables one last time and they all looked plugged in. 

Once TF's were given the okay, the offset settings for the MC mirrors for when we flashed the mode cleaner successfully in the past were applied and the mode cleaner flashed right away. YES.

ISI on west side unlocked and door went on :-) :-)

Stuart/Arnaud have a detailed log of particle counts/timeline/particles per square inch on the optic which will post to this log

Pic: The HAM closeup crew. Thankyou to all who have helped get LHO to this point. Its amazing to be to this point and when we had schedulded it

J. Kissel, S. Aston

I've gathered TFs of the IMs before the HAM2 doors are installed. They're free, see first attachment.

More importantly -- confused by a large discrepancy between model and measurement, I noticed in
/ligo/svncommon/SusSVN/sus/trunk/HAUX/Common/MatlabTools/plotHAUX_dtttfs.m
that the coil driver transconductance had not been updated (reduced to 0.998 [mA/V]) since we reduced the coil driver strength (see LHO aLOG 8758). Correcting this, the calibration *still* was off by a factor of 2ish. Exploring further, I found the OSEMINF filter's "to_um" filter was a gain of 0.0391251 [um/ct], instead of the expected 0.0233333 [um/ct] (see LLO aLOG 4291) that installed in every other suspension. As such, I multiplied the measurement by a correction factor of (0.039 / 0.023) ~= 1.6, and achieved the expected match of model and measurement.

I've now corrected the OSEMINF "to_um" filter, and corresponding "norm_um" filters in the DAMP bank, changed at 10:20:21 PDT (17:20:21 UTC). I've also cleared out all unused extra filters in the DAMP bank to avoid future confusion.

Comparing against previous measurements we see resonances in the same place, but off by the expected calibration factors (see last 4 attachments).

I would have compared against LLO's results, but data from each of their SUS show a wildly different overall scale factor, making comparisons difficult at best. I'll see if Stuart can chase down the difference once he get's back to LLO.

Jeremy B, Matt H, Jeff B, Apollo

As you may remember from one of my alogs last night, i forgot to pull the FC on the witness optic in HAM3. It was decided to play it safe and pull the door to get at it. So before anyone else started in chamber work we quickly pulled the door. Particle counts in cleanroom were 10 counts and straight after the door came off was also 10 counts in chamber. Door came off at 9.09 am, Half the ISI was locked....and whilst ISI was being locked I looked at MC2 optic. Looked same as yesterday which is awesome. I tried pulling the FC on the small optic and in doing so it ripped so I only had a little bit come off with first go (I think the layer was to thin). So had to try to get at it with a gloved hand to get the rest. We did so, but it definitely meant that the cautious approach was the right one. We did a quick check to make sure we got all the FC, unlocked the ISI and the door went back on at 9.22am (off for around 13mins). Jeff checked particle counts as the door was jamming shut with the chamber and saw no puff of particulate. 

Stuart has a detailed log of timeline and particle counts that hoping he will add to this

Matt H.  requested that we verify the ISS PDs were still connected in vacuum.  I was able to get to the all 16 cables and tested each pair. They all tested fine with a reading of approximately .384VDC Anode to Cathode and OPEN Cathode to Anode on my Fluke 87V set to diode test. The last set I tested seemed to be reversed so I left them disconnected until I can have better access to the chassis under the chamber behind the HEPI support Structure.

I have reconfigued the Vacuum Alarms To Cell Phones to not alarm on the missing MX Y1 beam tube cold cathode (343B) and replace it with the cold cathode on the other side of the gatevalve (344B). This is a temporary change until 343B gauge is repaired.

WP4750. Shivaraj and Dave.

With Stefan's kind permission, we added the first version of the PCAL front end model to h1odcx as a CAL top-names part. We have not restarted the DAQ, so the data from this model will be corrupted until we do so.

Channels in this new system have names which start with H1:CAL-PCALX_

JeffK HughR

Look pretty good, Jeff looked pretty close.  Maybe I'll get a chance to plot a Dof by Dof for better compare which we did on screen.

Meanwhile see the attached for a Global Basis comparison with data from back in November.  Current data is bottom set (see title); two bands zoomed in 1) main resonances 2) upper frequencies where the ISI cable bracket might show itself.

ITMx has been unlocked for SEI TFs.  ITMy has been locked for ACB install.

Summary: in preparation for beam arriving in HAM6 / ISCT6, I wanted to explore the potential for mode mismatch to the OMC, and how it might be corrected.  I found that for essentially any reasonable combination of errors in optic positions and ROCs, the mode matching can be recovered by a small adjustment to SR2.  (Given the way the SRC is designed, I don't think this is surprising to anyone -- it may even be intentional! -- but it was an interesting exercise.)

Details:

At L1 they observe a mode mismatch to the OMC of ~25%, depending on which ITM supplies the bounce.  Lisa found that this could be caused by a small (1.5cm) change to the SR2-SR3 distance, assuming the PRC length is nominal.  At LHO we are a 2-3 weeks away from measuring the beam arriving in HAM6.  In principle, there may be errors in the position of any of the optics on the order of 1cm, and errors to the ROC for the curved mirrors (of order ~few cm?).  The question is, if we are very unlucky and the initial mode matching to the OMC is bad, can we correct it in a simple way?

I used Lisa's script from LLO:8565 as a starting point to estimate the mode mismatch that could occur from small errors in the positions and ROCs for optics in the output path, SR3 to OMC.  At LHO the PRC length has been measured to better than 1mm; it's very close to nominal, so for now I assume the positions of the PRs, the BS, and the ITMs are correct.  That leaves six optical components with un-verified positions: SR3, SR2, SRM, OM1, OM2, and the OMC.  (I fold errors in the position of OM3 into the position of the OMC.)

Modeling a beam subject to small variations in eleven optical parameters is a lot to keep track of in closed-form, so I implemented a Monte Carlo approach: for 10k trials I independently varied the longitudinal position and ROC of the six optics in the output path, and calculated the mode overlap with the OMC waist (w0=490um).

Errors in position were drawn from Gaussian random variables with sigma = 2.0cm; these were applied to SR3, SR2, SRM, OM1, OM2, and the OMC.  Errors in radius of curvature were drawn from a Gaussian distribution with sigma = 5.0cm; these were applied to SR3, SR2, SRM, OM1, and OM2.  I'm not sure if these values are reasonable (2cm in position sounds like a lot), but they seemed like fair conservative guesses, based on the as-built dimensions for L1 in E1200274-v3, compared to the nominal values in T0900043-v11.

For 10k trials, the median overlap with the OMC waist after varying the parameters of the optics was 0.85; the distribution is shown in Fig2.  This median is better than what's observed at L1, which may mean they got unlucky, or the magnitudes of my errors are too small.  (NOTE: for simplicity I am using a single bounce off ITMX with the nominal ROC of 1934m.)

Next, I used a la mode's optimizePath() function to correct the mode mismatch by varying the position of SR2.  Based on table layouts this seemed to be the easiest optic to move.  The range on the optimization of SR2's position was +/-5cm.

The result is that even for very bad mode overlaps, the errors can be compensated by moving SR2.  And, whether or not the overlap can be completely recovered is only a function of how far you can move SR2.  (I.e., if we are terribly unlucky at H1, maybe we can move it by more than 5cm.)  This might be known already to optics experts, but it was surprising to me that even for large errors in optic ROCs the mode can be corrected by changing a single degree of freedom.  I guess this is what you gain when your beam-reducing telescope has a short Rayleigh range?  (Flip side: we're really sensitive to the position of SR2 and SR3.)

In the attached: Fig1 is the distribution of mode overlap to the OMC, for 10k trials with independently varied parameters.  Fig2 is how well you can improve things by moving SR2; the horizontal coordinate is starting (mis)match, and the vertical coordinate is corrected (mis)match, after at most a +/-5cm change to SR2.  Fig3 is a comparison of how much you need to move SR2 vs how much you get back.  The scripts I used are there too.  It's not a very elegant implementation, for 10k trials it takes way too long to finish, something like an hour.



Notes:

 - This is all fine from a mode-matching perspective, but I don't know enough about optical cavities to say whether changing the SRC length by 5cm is okay or a complete disaster.  Also, I think that a la mode's optimization procedure changes only the position of the optic in question, and doesn't take into account the changes to relative lengths.  So, when it moves SR2 by 5cm, a la mode is increasing the distance from SR3 to SR2, and decreasing the distance from SR2 to SRM.  This would be fine if SR2 was a lens, but it's a mirror; if the position changes by 5cm the SR3-SR2 and SR2-SRM distances should change in the same direction.  (I think that since the SR3-SR2 distance is the important one, this is does not change the results, but I haven't checked in detail.)

  - I belatedly realized that the ROCs for the SR optics have been measured and they're listed on the core optics website (galaxy.ligo.caltech.edu/optics).  So, errors in the ROC of 5cm are probably way too generous.  I'm not sure about the OM1 and OM2 optics.

 - Of course in order to correct something you need to measure it first.  If the mode mismatch is bad we'll have to characterize the beam on ISCT6 with Chris M's beam scan technique or something similar.  It might be worth modeling how accurately we can measure the necessary correction to SR2's position.

J. Kissel, R. Schofield

I discovered a lonely, forgotten, disconnected GS13 hiding under BSC9 (H1 ETMX) chamber today. I attach pictures. 

Things that Robert and I can surmize:
- It's serial number is 574, and has a "property of the USGS, greater than $5k" sticker on the side with the number G12077 and a bar code.
- It may have been used for S5/S6 feed-forward studies (Will check with Mike, Keita, Richard)
- Ski may have purchased it, given the bar-code on the side (Will check with John)
- It's a 2005-ish era model, based on the color of its can and unfinished look of the feet.
- It's currently configured as a horizontal
- It claims of a broken locking mechanism, but after a few turns the mass seemed locked enough for transport
- It's functionality is unknown.

Finder's keepers ...