This is a log-log plot with a 1/t curve superimposed with exponent of 0.85. Also shown is a zoom in of the last 10 days.

It appears that we have cleared up some virtual leaks(annuli?) in our pumping exercises.

Attached are plots of oplev signals of ETMY and ITMY, as well as the arm cavity reflected power (ALS-Y_REFL_B_LF_OUT).
Plot 1 shows the signals in lock.
Plot 2 is a time series in lock.
Plot 3 shows the same signals as plot 1, but out of lock.
Note that neither channel is properly calibrated yet. (TBD)

Conclusion:
- The limiting peaks are ~0.44Hz and ~0.55Hz.
- Both ETMY and ITMY show the motion.
- Our slow feed-back of the length signal to ETMY M0 makes them worse for ETMY in-lock.

Started transfer functions measurements with DTT on MC2 for M2 and M3 masses. ISI is damped. Lock filters and alignment offsets have been turned off.

(Alexa, Kiwamu, Daniel, Stefan)

Since the HAM1 was leveled, we first fine-tweaked the PR3 alignment to maximize the ALS-C_TRY_A_DC signal.
New PR3 alignment: P:-150, Y:125 (i.e. we moved -5ct in pitch). We have not re-tweaked the IR beam.

Then we build the beat node path on ISCT1. Daniel fixed the SHG TEC (I have not idea how). So far we only used Kiwamu's pre-calculated mode-matching solution, without fine-tweaking it. We had to steel a power supply diode from a neighboring table to power the 18V needed for the broad-band PD. (Needs its own power cable.)

With all that we got a nice beat-node up to 100mVpkk (out of about 600mVpkk that we guess from a back-of-the-envelope estimate). Still room for improvement. Most importantly though, the beam was fluctuating a lot. We need to revisit the ETM and ITM suspensions/ISIs.

Also I did fine-tweak the transmission monitor table (TMTS) alignment slightly in pitch to reduce the arm intensity fluctuations: from -14400 to -13820 counts.
The arm is still moving too much tough.

To do next:
- Stabilize the ETM and ITM to reduce arm motion
- Measure beam profile out of the corner SHG
- Measure beam profile out of the arm
- Wire the beat node PD's power cable
- Configure the electronics for feeding back to the input mode cleaner CM board.


On that note: We should really change our nomenclature for the "Common Mode Board". The name is purely historical. We have so many of those now, and most of them have very little to do with a "common mode". My proposal: the "Sigg Servo Board"...

• 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