Diagonalization measurements were run on the H2 ETMY M0 & R0 top masses yesterday.  Results are attached.  The results show ideal isolation for the two DoFs on both masses.  Each DoF on both masses is at least 20dB isolated from the other OSEMs, which is well above tolerance.

M0 Yaw:
25ct amplitude at 1.3Hz
21dB isolation

M0 Vert:
1000ct amp. at 2.2Hz
25dB isolation

R0 Yaw:
25ct amplitude at 1.3Hz
24dB isolation

R0 Vert:
1000ct amp. at 2.2Hz
23dB isolation

Yesterday, Mark L. and Chris spent some serious time in chamber doing the final clean-up inside BSC8 so that the door could go back on ASAP. The interior of the ACB was wiped down with a dry wipe to collect the glass dust at the lips so that it could be easily vacuumed up. During this process, one additional free range washer was found on the lower shelf. The two central planks of the BSC flooring were removed from the chamber and set aside in the staging cleanroom. The remaining planks on the east side of the chamber were stacked on top of the west side flooring so that the chamber floor could be inspected, vacuumed, and wiped down. There was very little visible debris on the east side of the chamber floor or rim. Next, the east side flooring was wiped down and re-installed so that the planks from the west side could be stacked up. The west side of the chamber floor was inspected, vacuumed, and wiped down. As expected, the west side of the chamber floor and the rim had numerous glass shards as well as dust (likely from glass). After wipe down, the west side flooring was returned to its starting position. Flooring hardware was installed around the perimeter. The central planks were wiped down and returned to position along with the accompanying hardware. The GV1 nozzle, the nozzle to GV3 and the Y-beam manifold as far as the first joint were vacuumed and wiped down.C-3 covers were removed from both structures (Quad Upper Structure and FM)so that they could be inspected. Thomas came in to swing the ACB back into its usual position. Some particulate, most likely glass, was found on the metal masses of the FM and carefully vacuumed off.

Today, Mark and Chris completed the work in BSC8. A clean step-stool was placed into the chamber so that the upper parts of both structures could be given a close inspection: nothing distressing was found there. However, inspection of the support tube bellows revealed glass shards in the C-4 bellows.The shards were vacuumed up. Five witness plates were placed:
1. Bottom of GV1 nozzle close to septum;
2. Bottom of bellows convolutions in GV3 nozzle;
3. Bottom of bellows convolutions in Y-beam manifold;
4. BSC flooring/ACB face as landmark (approximately parallel with quad optic face);and
5. Center of BSC flooring (approximately center of space between the quad and FM, which seems to be a "dirty" spot).
O-ring protection was removed. Then, o-rings were partially removed (lower half)and closely inspected for any glass debris. The o-rings looked good so they were wiped down and re-installed. The chamber door was vacuumed, wiped down, and then, re-installed. This concludes the physical clean-up of the fiber break at BSC8.

Thomas, Mark (Apollo), Caleb (Apollo), Chris (Apollo)


The Arm Cavity Baffle in BSC8 is returned to its suspended position, the balance seemed good.  I had double checked the crevices and the hardware to make sure that we didn't leave extraneous hardware laying on the baffle.  During the course of repositioning the assembly, we could only find 3/4 of the 1/4-20 SHCS on a tray outside of the chamber but we had a spare bolt of the same size that came from removing some of the swingback tooling (class A).

Conlog is running again after being stopped yesterday afternoon for code changes. It was restarted a number of times since then. The channel list has changed. Currently 20,208 channels are monitored, 4,113 channels are unmonitored.

Attached are plots of dust counts > .5 microns.

Praxair delivery

https://ligoimages.mit.edu/?r=18431

See entry 2426

 B. Bland, J. Garcia, J. Kissel, T. Sadecki

After the ISI shakedown, and lamenting the loss of H2 SUS ITMY, we found that H2 SUS FMY seemed to have survived according to first visual inspections, but OSEM signals / alignment looked pretty bad on the digital side. The last time FMY's TOP to TOP TFs had been measured (see aLOG 2237), it was identified that there was some rubbing, but the source was unclear. After the initial inspection, (and a couple of measurement tries by both Jeff and I), we identified severe badness in these TFs. Travis, yesterday, then worked some magic -- but now, as is evident from an "after" measurement -- we're back to the rubbing that was seen before the ISI badness.

Attached are plots showing the story.
2012-01-09 -- Approved post-cartridge, in-air data [[but was taken before EQ stops were adjusted to 0.75 nominal distance]]
2012-02-15 -- At vacuum, first sign of rubbing [[two differences -- in-air vs. in-vacuum, and EQ stop placement]].
2012-03-13 -- post ISI badness, in-air TF, crazy bad rubbing (later identified to be TOP/M1 vertical blade spring / mass stops that may have rattled down during the Shakedown.)
2012-03-14 -- Post-Travis fix of TOP EQ stops: back to black.

The data shows:
- Indeed FMY has survived the Shakedown. *phew*!
- Because Cyan lines up identically with Black, I surmise that there's no change to whatever mechanic rubbing that was caused by bringing all the EQ stops in to the nominal 0.75 +/- 0.25 mm

We've elected (i.e. Landry made the call) to go for close up of doors given this data. So, when we go back in the chamber to restore the repaired, wire suspended, ITMY, we'll attack FMY with more rigor.

Yesterday, Calum prepped the new FirstContact application process (spray on).  Today, Jeff, he and (a little bit of) I executed the new technique after some vacuuming of the suspension.  This went well with little dripping (our biggest worry) observed.  We then split the chains (lower R0 not from lower M0) and prepped for spraying one more of the 4 exposed optical surfaces in the suspension.  Pictures posting to ResourceSpace soon.

Attached are plots of dust counts > .5 microns. From a plot of H0:PEM-LVEA_DST15_MODE it appears that the dust monitor in the clean room over BSC8 was disconnected for a short period of time.

In response to the shield grounding problem associated with the ring heater in-vacuum cabling, I cut the connection to the in-air D-sub backshell at the end of the cable attaching to the ring heater driver.  This cut effectively creates two portions of the system cable: an in-air shield (grounded at the driver), and an in-vacuum shield (grounded up next to the ring heater itself).  

Using this fix, there is no need to re-engineer the in-vacuum shield termination for the ring heater.

The troubled binary IO code (https://alog.ligo-wa.caltech.edu/aLOG/index.php?callRep=2420) was fixed by JoeB. Here is the not-too-accurate recap of things as I understand.

TMS was working fine in an old binary I/O regime.

Several days ago, there was a change in the binary I/O code. Unfortunately some typos were introduced in the TMS model (different typo from what Jeff wrote in the earlier alog) when it was copied from other model, creating some funny name channels that nobody could have guessed. This caused the first problem (i.e. not being able to turn the coil driver DAC input on), and was fixed by Joe by fixing the typo and then making an MEDM screen to control binary IO.

The same code change had other side effect. The whitening/dewhitening filters were in FM9 and FM10 in the coil output filter module in the old days, but in the new code they are standardized to FM2, FM6 and FM7 (FM9 corresponded to FM6, FM10 to FM7, and we used to turn FM10 on and off instead of turning FM2, that is an inverse filter of FM7, off and on). Because of this we couldn't match analog and digital, therefore we couldn't damp the mass after the coil output was enabled. This was fixed by Joe by running a matlab script to copy standard set of filters (Joe had to fix the script first).

Now that things are working, I asked Dave to make a safe.snap file so the model can automatically burt restore after restarts.

Acoustic door was installed today. Reiboldt-Mallonee will be onsite tomorrow to put backer rod and caulk in.

Electrical work is on hold until we get parts from Gerbig.

Since we have access to the suspensions in WBSC8, interest was expressed in attempting to cure the rubbing that was noticed on FMy.  Before chamber cleanup of the broken fibers began (since they will be removing the flooring to clean, therefore limiting access), I examined the suspension to see if I could identify the source of the rubbing.  It appeared to me that the EQ stops on the top of the top mass (L1) were in fact touching the mass.  Due to constraints from the tablecloth, these EQ stops will not accept a lock nut.  Additionally, the threads for these screws are not very tight and so do not provide any sort of locking of their own.  Therefore, I am not surprised that the rubbing seemed to get worse after the shaking incident as the screw may have rattled down even more.  I backed off both of these screws ~2 turns so as to be sure that they were free and clear.  Upon further inspection of the suspension, I noticed that the lower right (LR) BOSEM flag was rotated ~30 degrees in the BOSEM bore, and may have also been rubbing.  I rotated this back into nominal vertical position.  Jeff Garcia then began a round of TFs to check that the rubbing had been alleviated.

Jim and I installed vented hardware into the holes we tapped for the ACB work.  So no more dropping chips during strong HEPI motion.  We did not bore-scope the holes.