Prior to HAM3 chamber close up, MC2 transfer functions have been running last friday.

The attached pdfs show :

1. Comparison between last TF damping on and model
2. Comparison between last TF damping off and model
3. Comparison between last TF LHO damping on/damping off and LHO phase 3a (in december 2012)
4. Zoomed version of 3

Measurements are consistents with model and previous data, and MC2 has been approved for Phase 3a testing

- Cheryl, Chris (Apollo) 

HAM2 and HAM3 IO component bolts are now torqued to spec.  The actual inch-pounds is unknown, as we were working at the end of the range of the torque wrench.

I checked the 1/4-20 bolts that are holding down cables and found a couple in each chamber that were loose - IO and SUS.

I found a couple IO 1/4-20s in HAM2 that seemed to be over torqued, and backed out one of them.

This clears all of the known IO mechanical changes needed before close-out - HAM2/3 given back to SEI.

I restarted the user model and the IOP model this morning, there was a 55 second timing error that was causing excitations to behave badly.

Kiwamu I. Thomas V.

We've aligned the in-chamber optics for both HAM2 and HAM3, this is with the ISI balanced and locked (hopefully this does not change the pitch and yaw significantly after pumpdown and unlocking).  We only turned knobs on the optic mounts and did not translate anything on the ISI table so this should not have changed the #balance for @SEI.  The beams going in and coming out of the chambers look clean, I believe everything that needs to be done for these optical levers can be finished outside of the chamber.

HAM's 2 & 3 are locked for AOS closeout. BSC2 is unlocked, but it looks like we have a bad CPS there, so we may be locking again shortly.

Beamsplitter transfer functions have been running over the weekend in order to fix any issues during the day if needed.

The attached pdfs show :

1. Comparison between last TF damping on and model
2. Comparison between last TF damping off and model
3. Comparison between LHO damping on/off and LLO phase 3a (feb 2013) TFs
4. Zoomed version of 3.

Vertical degree of freedom is noisier than expected between 1.5 and 3Hz (3rd page of each pdf).

Kiwamu and I went into the PSL this morning, and added two irises to the ALS doubling path (labeled ALS iris 1 and 2) to use as references for the alignment into HAM1 and out onto ISCT1.  We moved the second lens in that path about 1.25 inches closer to the periscope to get the beam better collimated leaving the table.  A mode scan of the resulting beam is attached. The spacing of the measurements is small compared to the Rayleigh range, so the fitting is not great, but we have a pretty well collimated beam with a radius of 3.3 mm coming onto ISCT1 now.  We also aligned the path up o the SHG again.  For the purposes of calculating a mode matching solution, the first steering mirror is 4+1/2" from the bottom periscope mirror, the second is 18+1/2 inches away, and we have about 13 inches after the second steering mirror in which we can place the SHG.  

Again, the beginnings of a list - Things we need to address during the next vent opportunity (after HIFOy test):

Cleaning of BS optic

Set top stage BOSEMs in position to account for buoyancy (flat out forgot to do this and ran out of time)

The beginnings of a list - Things we need to address during the next vent opportunity (after HIFOy test):

PRM optic cleaning (if not all optics on table)

Although it "passed" the data round, investigate further some PR2 minor TF cross-coupling (SUS: see emails circa 4/11/2013 Kissel/Pele/Barton

Recenter any outstanding lower stage AOSEMs

Kiwamu, Sheila

We removed the guillotine on the viewport and saw that the beam is nice and Gaussian.  The guillotine was also probably causing polarization problems, now that we have removed it the ghost beams off the 5% reflector and the mirror after it are much better.  
We then measured the beam profile (with PLCX-50.4-309.1 installed right after the periscope mirror, at 0.223 in the units of the plot which start from the inner edge of the enclosure walls), the data and a fit is attached.  Propagating this beam back towards the PSL gives an answer that does not make much sense, I would need to be off by 2cm in the lens position to get a reasonably collimated beam to propagate 10m back to the PSL, but I double checked my measurements and they seem to be OK.  

The conclusion is that if we want to adjust the lenses to make sure we will not have problems with clipping on the PSL periscope upper mirror (or other places) in the future, we probably need to measure the beam inside the PSL first.  

Attached are plots of dust counts requested from 5 PM April 11 to 5 PM April 12.

At seemingly random intervals this morning, (and looking at the trends, last night as well) the dust monitor at end Y (location #2, labeled 'S') was reporting extraordinarily high counts for particles > .3 microns, but 0 counts for particles > .5 microns. This dust monitor had been recently returned from the dealer after being sent in for a sensor failure and calibration. I went to end Y and moved it farther from the beam tube and toward the middle of the clear space in the VEA. It had been within a couple of feet perhaps of a small pipe that was venting a high flow of air. However, after moving it, I saw the > .3 micron counts skyrocket again. I went back and got one of the HHPC 6 dust monitors to compare it to, but could not catch it happening again while I was out there. I put the HHPC 6 dust monitor near the pipe venting air, but didn't read anything nearly that high. I went back and installed a second 227b dust monitor (location #1, labeled 'C') near the electronics racks for comparison. This dust monitor was also recently returned after being sent in for repair.

The plot for end Y is for 1 day and 12 hours of full data, going back from April 12, 19:00 UTC.
T0=13-04-11-07-00-00; Length=129600 (s)
129600 seconds of data displayed

Transfer functions are running over the weekend on HAM2-ISI as well.

HAM2 was unlocked. It was a bit difficult the get the tight covers to stay away from the ISI without the rods we usually have (used on HAM3, see attached pictures). I added a couple clamps to keep the sheet in place over the weekend.

Installed the periscope inside chamber, but it does not look right, there is no clear line of sight, the BS elliptical baffle is on the way.
We are going to continue to work on it next week.

Starting several rounds of transfer functions overnight for phase 3a testing prior closing HAM2 HAM3 chamber.
Measurements will run until tomorrow afternoon, and will be paused if needed to go in chamber.