• Green laser at EY was shuttered for SEI work in LVEA. IO and ALS light pipes were shuttered as well.
• Shutters open at 2:30, HIFO work ongoing.
• Thomas working on optical lever at EY
• Hugh picking up parts at EY

The fluid analysis for EndX after flushing for almost 5 weeks can be found at T1300527.  All the LHO HEPI Fluid Analyses can be found at T1300521.

     Electronics ready, in-rack cables 90%Here is the current status of the aLIGO SEI work regarding the HAM chambers. Everything in bold is to be completed for HIFO-Y. Everything in red is a change from last week's status. Everything in green is available.

HEPI Actuator status:

BSC 9 was put into bleed mode Friday afternoon (6/7). The float level had to be adjusted as the pressure went up. The end X pump station was set to run ~80psi.

See my notes attached if you wish.

The Support Table was level to within 0.3mm.  I am using a different reference although they are tied together but the elevation it self is ~1mm higher than the elevation from 1 October.  Still, I think most will say this can be ignored.  So, we did not do any Support Table leveling with HEPI.

Moved up to look at the Optical Table, out of level about the same as yesterday, reasonable.  Removed 5kg of 'extra mass', that is, part of the mass I added to account for the to-be-installed components back in October.  There still remains some 14 kg of extra mass, to-be-removed later when more components are installed onto the Optical Table.  We shifted this mass around to level the table and got the level to +-0.1mm at -185.7mm local or -199.8 global, about ~0.5mm higher than in October and within 0.2mm of spec -200mm per D0901821.

The Extra Mass is not bolted down.  It consists of one 10kg D0901075 with 2 stacks adjacent each consisting of one D080001 & four D080002 masses.  The Extra Mass is located close to the East side of the Optical Table just South of mid-way.

Bias switched were turned ON on HAM1-HEPI to allow adjusting alignment, if needed, with offsets applied by the actuators.

After many changes to the pumping configuration we appear to be on a downward curve again. During the last 20 days of this pumpdown we have valved in main ion pumps, pumped and leak tested numerous annuli, valved in and out the main turbo and leak tester, changed out a few annulus ion pumps, and cycled the beam tube valves.

So far Kyle has not seen a significant response to helium testing. It is possible that we are now seeing the outgassing of all the assemblies in the vertex volume - 1xBSC, 1xITM, 3xHAM

Arnaud started MC1/MC2/MC3 M2/M3 TFs on Friday, but they were interrupted by Saturday commissioning activity. It appears they were in the middle of MC1 M3 when they were stopped, so I'm restarting them there shortly. Commissioning has priority so text/email me if you need them shut down.

(Daniel, Kiwamu, Chris, Stefan)

- Using PR3 we pointed the green beam to the center of the septum view port. some pointing references for PR3:
   PIT: -145, Yaw: 125  Center of septum view port, we left it there
   PIT clips at -85 and -206
   Yaw clips at +75 and +198

- Kiwamu moved the top periscope mirror in HAM1 up until the green beam was centered on it. The periscope yaw position agreed well with the center of view port. He then guided both the green ALS beam and the POB beam (actually IR, but we used green as alignment proxy) to ISCT1. Note that the POB beam does not yet have all its hardware, but we suspect it might be useful later. We dumped all stray beams on ISCT1, and put the green beam on H1:ALS-C_TRY_A_DC to have a reference.

- For the red beam - unlike yesterday -we were not able to get IM4 TRANS pitch to zero (using a MC move), possibly due to falling off the WFS sensors. For now we ignored this. 

- We then realigned the red beam following the same procedure as yesterday. (PR3/PR2 walk keeping fringes, putting PR3 to its desired spot. PR2/IM4 walk to optimize transmitted fringes). This actually gave us a signal in the POB quads (H1:ASC-POP_A_SUM_OUT and H1:ASC-POP_B_SUM_OUT)

- Finally we also hunted and found the PRM alignment. Power recycling fringes with a power gain of about 3 are visible on both POB quadrant diodes and as stray light on the ITM cage.

- The attached alignment snapshot reflects the fully aligned power recycling cavity (incl PRM).

I found the MC alignment offsets off and a measurement in progress when I got in, but I have no idea who is measuring, as I am the only one one site. Please call the control room.

Stefan

(Chris, Kiwamu, Mike L., Daniel, Stefan)

We entered HAM1 today, but did not find any green in it. Thus we started to look for some green in HAM2 and HAM3 through the view ports. By far the most useful port turned out to be the view port on the terminating flange of the MC tube - it allows for a clear view of the HAM2 baffle. With some beam wiggling it was easy to establish an alignment that let the green beam bypass the HAM2 baffle and travel all the way to the HAM1 periscope. (We did not move the BS, as BS and PR3 are very degenerate, and for the X-arm we won't have the BS.)

Unfortunately, while the green beam comes down the periscope of HAM1, it does not make it through the HAM1 view port - we can see it hit the vacuum tank. So we will have to go into HAM1 to realign the optics. This however can now be done on the PSL side of HAM1, eliminating any risk of accidentally damaging the septum view ports.

After we had established the PR3 (& BS) alignment that gets the green beam out to HAM1, we again found the red fringes in the arm, using the following procedure: Since we knew an alignment that produced fringes, we beam-walked PR3/PR2 from that location to the PR3 alignment that gets the green beam out, while maintaining arm fringes with PR2. Next we used a IM4/PR2 beam walk to maximize the arm transmitted fringes. Note that this did pull us off the ASC-POB QPD's.... not sure what to make out of this.

Below is a snapshot of both the initial in-air alignment and the current alignment that gets the green beam to HAM1 and red arm flashes.

Attached are plots of dust counts requested from 5 PM June 6 to 5 PM June 7.

Both the dust monitor at location 14 in the LVEA (H2 PSL enclosure) and the dust monitor at location 16 in the LVEA (H1 PSL anteroom) are indicating calibration failures.

The latest version of the HAM-ISI master model was updated from the SVN.  I started compiling it. make worked, but make install- did not. This is due to a part that the new HAM-ISI model expects from the BSC-ISI one. We did not expect such dependancy and soppose it is a copy/paste issue (dependancies can get tricky under simulink).

Here is the error message returned by make install-:
ERROR: For part: "isi2stagemaster/ISI2STAGE/ST1/SENSCOR/X_BLRMS"
Could not find the proper library reference.
Your model may be referencing a different source model than what is in the current library path.

ONE MUST NOT RESTART THE HAM-ISI MODELS FOR NOW

Today I estimated the position of the beam spot on the input mode cleaner mirrors, following the procedure used in LLO alog 5010. The results:

I couldn't find documentation on how to get to coil drive imbalance from P2L/Y2L gain, so I wrote up a short document in TeX describing the method to make reproducing these results relatively straightforward.

With the HAM1 East Door removed and help from MikeL & StefanB, we checked the level/elevation of the Optical Table.  As compared to the elevation measured 1 Oct 2012, the Table is still very close to where it was then, within 0.2mm; caveat: I am using a different elevation reference and we were not able to reach all around the table for a good spacial sampling.

The level however was off: the North Center area of the table was lowest with the Southeast corner higher by 2.3mm.  This makes sense as mass has been added on the North and West sides since it was level +-0.1mm on 1 Oct.  Also to consider, HEPI is floating with fluid flowing.  Before leveling the Optical Table, we will survey the Support Table and level it with HEPI.