The licenses for Matlab are now being served by a local CDS license server, which should reduce the vulnerability of network interruptions to Caltech in obtaining Matlab licenses.  This applies to new matlab sessions started from newly opened shells, existing open Matlab sessions should be unaffected.  Also this only applies to Ubuntu workstations at this time.

The only change you may see is warning messages on startup referencing non-existing directories in the matlab toolbox path.  We have licenses for more packages than are installed, which causes the warnings.  This will not affect your ability to use Matlab.  

Undamped transfer functions will start on opsws1 and opsws10 when HAM2 ISI measurements will be done

Matlab TFs are set to run on HAM3 suspensions overnight as follows:-  

- MC2 (HSTS) M1-M1 undamped TFs, Starting at ~6:00pm July 24th (local)
- PR2 (HSTS) M1-M1 undamped TFs, Starting at ~11:00pm July 24th (local)

When complete at ~3:00am July 25th (local), the measurement status will revert to OFF and damping loops will be restored to the ON state.

These measurements have been initiated from the opsws2 workstation.

08:45 Matt H. and Jeremy going into HAM2
08:50 Mike V. going into LVEA to help Mitchell with CPB
09:12 Stewart going into HAM3
09:18 Filiberto swapping ITMY and ITMX UIM coil drivers [WP 4748]
09:20 Hugh going to BSC1
09:38 Nathan starting unattended work with laser in OSB optics lab
10:12 Filiberto finished WP 4748
10:19 Mike L. going to LVEA west bay to work with Gerardo on optic charging experiment
10:47 Mitchell and Mike V. going to LVEA west bay to move CPB
10:54 Gerardo going to LVEA west bay to work on optic charging experiment
11:06 Hugh and Jim out of BSC1
11:44 Mitchell and Mike V. out of LVEA
12:51 doors going on HAM3
12:55 Jeff B. and Andres going to HAM3
12:59 Stewart going to HAM3
13:03 Richard going to end Y to take pictures through viewports
13:22 end X transitioning to laser hazard
13:43 Mike L. and Gerardo going to west bay to work on optic charging experiment
14:24 Richard back from end Y
14:45 Manny to end Y to turn off illuminator
15:15 Jim B., Patrick replacing light bulb in right side projector
15:16 Paul and Jordan to end Y to pull cable for accelerometer
15:18 Kyle starting WP 4749, PT343 valved out from beam tube volume
15:33 end X transitioned to laser safe
16:02 Mike L. and Gerardo out of LVEA
16:30 Gerardo and John W. discovered that the right side projector is overheating, taken down
16:45 Nathan will be supervised by Dick G. in the OSB optics lab

Closed 10" gate valve at X1-9 port on X1 beam tube -> PT343A,B now unpumped and no longer measuring beam tube pressure -> Ignore PT343B until further notice -> Replaced 1.5" O-ring valve at X1-9 with portable RGA assembly -> Will leave 10" valve closed for the next several days while I bake the RGA -> Following RGA bake-out, GV14 will be closed and the 10" valve opened for a few days so as to acquire pressure accumulation data on the X1 beam tube module 

(Matt H, Stuart A, Jeff K, Jeremy B)

After getting the okay from SEI, I unlocked the 4 HXTS's on HAM2. TF's were run on All 8 suspensions (4x HXTS, 4x HAM AUX) on the table and all were given the all clear. So SEI TFs should be good to start..once we damp the suspensions of course :-)

We took particle counts. Cant remember exact number but Stuart has the numbers and i believe will post

Jeff B, Andreas, Jeff K, Stuart A, Jeremy B, Matt H, Apollo).

Both doors on HAM3. Jeff B started by inserting optic Started on PR2 side as that is the "least" important of the two optics in tha chamber. There was a drop of FC under the optic (not from a run down the optic, obviously fell off during painting) so that was cleaned up easily. Once particle counts deemed good to go, first contact was peeled (there was a little bit of the outer crust left behind from say 2-3 o'clock position and 4-5 o'clock position.....I decided not to attack it with a swab and just leave it...Calu you need to practice your first contact outer layer painting skills :-) :-D). Its only a bit and well out of the beam path. Optic was unlocked and TF's taken. Once given the all clear door went on. Stuart has a log of particle countsduring process, timeline and also how many particles I deemed I saw on optic throughout the process.

Once HAM3 east door on, we checked particle counts on west side. These were low and so went to peel FC here. Found that top gun nitrogen tank low, so swapped out before blowing to peel FC. Once swapped, peeled FC, again unlocked suspension and then did TF's. Once these past door went back on. They had some troubles getting a good angle to put door on so took a little longer than wanted. Again Stuart has log of timeline, particle counts, particulates on optic, etc.

I talked to Travis about mobility wafer and if he wanted it replaced (by replace I mean swap out the the wafer already in it....it was put back in its original position before the ISI guys balanced the table by Travis and I) before we closed up. He suggested to leave it as looking for a delta if anything moves from time of closing/pumping down...so I left it as is.

Damn...I know one thing I forgot.....to peel the FC on the small optic...how did I forget that #facepalm.......hmm  I wonder if I took off a viewport I can reach in and get it. Its on the outer leg of the MC2 suspension. Will talk to Calum about.  Who has the longest reach at LHO ? We may just be able to get it from the viewport.....To all and sundry....dont let me forget for HAM2............

Running from opsws3. No touching.

Not too bad to rebalance but only because everything needed was in the LVEA.  One of the four 10Kg Optical Table Masses(D0901075) had to be removed as there was so little wall mass on the West side of the ISI walls.  The bottom mass of the two stacker was removed and the upper damped mass was moved to the table top onto the damping viton.  So all three masses remaining on the table top are unbolted and resting on viton damping pads.

The total mass reduction of the Balance Mass Payload is 3.5kg.  Will update the drawing for this as-built.

This morning Hugh and Jim rebalanced the BSC1 ISI.  In order for them to test, I jumped in and unlocked the SUS.  I ran quit TFs of V and P DOFs on both the main and reaction chain to confirm the SUS is healthy enough for ISI TFs.  SEI is launching testing on BSC1 now.

Considering it is my last day, I decided I should write up a summary of what I have been doing this summer.

Summary:
The lid of the laser was put on too early, alarm should be put in place at 70% relative humidity inside the laser to warn of a leak.

Details:
In the laser room, there was a leak on 7/1. When I looked into it, there were no clear indicators in the Laser Room temperatures or relative humidity levels, but I finally found the right channel inside of the laser box. The relative humidity inside the laser box usually stays around 40% has never gone over 60% in the last two years until this leak, when it spiked at about 85%. After the initial leak, the humidity went way down to about 35% because we removed the lid and really dried it out, but once we replaced it, the humidity jumped way back up again. We must have put the lid on too early, but it is slowly drying out. Today, the humidity is sitting at about 60%.

In the attached photos, the first one is a plot of the relative humidity in the laser box over the last two years, and you can see it only gets close to 60% one time (excluding the leak). The second picture is from the leak until now. You can see in this one the first peak is the leak, then it goes way down because we dried it out, and suddenly peaked again. My guess is that we put the lid back on too early, and it may still need to dry out more.

I believe the slow up and down trends in the humidity are due to the changing seasons. It tends to be more humid in the summer and less humid in the winter.

Summary:
In order to reduce temperature differences between commissioning mode and science mode, we should keep the temperature in the laser room at about 22.8 degrees C to keep it consistent with science mode temperatures which are much harder to change.

Details:
In the most recent switch from commissioning mode to science mode at 2:00 PM on 7/14, there was a difference of about 3 degrees C in the Laser Room, which is better than previous switches which have had a 4-5 degree difference. The changes are more significant on the temperature sensors on the table than the ones in the air conditioner. My assumption is that this is because the air conditioner keeps them cooler most of the time until they are shut off during science mode. The temperature inside of the laser only changes by less than 1 degree C, and seems to only be slightly affected.

The third picture attached is a plot of the four temperature sensors in the Laser Room during a transition from commissioning mode to science mode. The two graphs on the left are in the air conditioning units in the Laser Room, and the two on the right are on the table. I think the sensors on the table should be moved to the floor to prevent other factors from affecting them.

I also believe the names for the PSL environment sensors may have been mixed up, the thermometer on the south side of the table is closer to the laser box and generally is a few degrees warmer, but it is labeled as north, so this should be looked into.

(Jeremy B, Jeff B, Andreas, Matt H)

Jeremy and I went in and bolted the baffles back onto the PR3 structure, put the ballfe back in front of PRM, and put all the EQ stops that we had to take off to first contact back on the small triples. We also clipped off the peek ends on the cable ties to try to reduce the peek load in that chamber.

Whilst doing this Jeff and Andreas checked the PRM grounding issue (I think they said they thought it was clear..will have to check) and also put on the 4" witness plate holder and the 1" optic (both are by PRM to stay out of the way of beams).

Seeing as SEI were still balancing in BSC1, Jeff went off to deep clean BSC3 and Jeremy and I deep cleaned HAM2. That way all the particles we stir up in both chambers can settle over lunch and we can in theory put doors back on HAM3 after lunch. We vacuumed/wiped in bellows, around the septum, around the septum viewports, in and around the support tubes, under the ISI, on stage zero of the ISI, on the ISI table top, in and around the small optics, on the suspension structures. So the deep clean for this chamber should also now be done. We should give it a quick once over again before we removed FC, but to get that deep clean out the way is good.

Also the cleaners after we cleaned inside the chamber, very kindly cleaned inside the cleanroom in HAM2....and also inside the cleanroom in HAM3 in preparation of the doors going on this afternoon (on HAM3 I mean). They said they saw stuff come up so was a good idea to get it cleaned. They will also clean inside HAM2 cleanroom in the morning

SEI should now be good to go ahead and balance. Reminder, HXTS triples locked on intermediate and lower stages, upper stage unlocked and so are the HAM AUXs

Particle counts:

In HAM2 cleanroom before start work

All counts zero

IN HAM2 chamber start of work

0.3um...30 counts

0.5um...20 counts

0.7um....20 counts

1.0um..10 counts

rest zero

In HAM2 after everything put back but before cleaning

(Cant remember numbers but I think the counts was in the teens for 0.3um, and 7 for 0.5um..thats what I seem to recall thats what Jeff B said)

In HAM2 after cleaning

0.3um....410 counts

0.5um....210 counts

0.7um....150 counts

1.0um....130 counts

2.0um....90 counts

5.0um...20 counts

So we definiitely stirred stuff up cleaning and I b elieve made the right call to clean this chamber now before pull FC this afternoon to allow everything to settle.

Uploaded a couple pics if people interested in temp/humidity

This morning, with Hugh's help, I went into BSC1 and unlocked and rebalanced the ISI. Rather difficult, as I had to use the masses on the side of St2. At one point, I had to cram my body as far up into the dome as I could physically fit to remove mass off the top-most mounting points. The floating position looks good, and the ISI is currently unlocked (per Betsy's instructions), but the lower stages of the quad are locked on the barrels. Will try for Tf's tonight, if possible.

Removed UIM units from SUS-C5 in CER:
U33 S0900307
U32 S0900306

Replaced with UIM units that have been modified per E1400164.
U33 S0900301
U32 S0900308

Filiberto Clara

no restarts reported

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.