Interesting pressure trends on X & Y beam manifolds. See my previous aLOG about rate of rise test followed by pumping on just turbos (IPs valved out). PT180 (y-arm) trend has shifted and headed up! Does this mean the fault is in IP6 and not a leak?

After speaking with Chandra, I've turned the RH drivers back on to do a test on the HWSY alignment right now.

I'm going to turn them off again in about 40 minutes.

Because commissioning work is starting in earnest now, all of the seismic systems have been restored to their nominal configurations. This means ITMX & HAM4 HEPI's were unlocked yesterday after the cleanroom was moved out of the way, all HEPI's and ISIs are back up and running and all sensor corrections (including BRSs) are running on all chambers.

The only difficulty we found was the GS13 gain switching on HAM2 is no longer stable (ie we can't switch GS13 gains while the ISI is isolated). Hugh and I are working with Fil to try to figure that out, but this is a new "feature", we will probably be opening an FRS on it soon.

   Peter K. & Jeff B.  ECR E1700096

   Installed the PSL Air Trap/Bleed in the Crystal Chiller return line. The installation went well. Encountered one small issue. The pipe being cut was installed about 6 years ago. It did not cut as cleanly as the new pipe. On a couple of cuts the last third of the pipe broke before it was sheared through. Will need to be cognizant of this when installing the next three assemblies. 

   When the chiller was restarted the water compressed several inches of air in the standpipe. The ball valve at the top of the standpipe was used to bleed off excess air. I left about 4 inches of air trapped in the standpipe to act as a water flow damper. 

   The remaining three air Trap/Bleeders will be installed during the next big vent.         

From 1 PM to 4 PM local time.

Good catch report:
I told Corey it was alright for him to open the high bay rollup door into the LVEA to push a pallet into the LVEA. Later I remembered that the LVEA was in laser hazard and therefore he should not do this. I managed to run over and stop him before he opened the door.

20:22 UTC Corey taking forklift to highbay to drop off pallet.
20:30 UTC Filiberto to end stations to check documentation.
20:40 UTC Karen driving car to VPW
20:42 UTC Corey opening high bay outside rollup door, driving forklift into highbay, dropping off pallet
Aidan and TJ to HAM4, work on HWS table
~ 20:59 UTC Let a truck related to Norco through gate. Could not understand driver after three attempts.

Gerardo changing IP6 from dualvac to gamma controller
21:22 UTC Filiberto back from end stations
22:13 UTC Betsy to LVEA to store equipment
22:17 UTC Jenne, Vaishali and Jeff to LVEA to talk to Aidan
22:25 UTC Jenne and Vaishali working on MC table
22:25 UTC Jeff K. taking transfer functions of ITMX, turning on sensor correction for ITMX
Jenne and Vaishali out of LVEA
23:13 UTC Aidan and TJ done in LVEA, TJ returning to get something
23:19 UTC TJ back

Attached are pictures of the pressure regulator and barometer for the auxiliary water
cooling circuit.  This circuit serves the power meters and water-cooled beam dumps on
the table.  The pressure in the circuit was ~3.5 bar, which seems to coincide with when
the regulator is fully closed.  The pressure is ~2.2 bar with the regulator fully open.

Useful information to have when or if we decide to remove the regulator from the cooling
circuit in the quest to simplify things.

[John, Chandra]

More investigation on leak hunt of x-beam manifold. Here's what we're trying now:

• Valved out IP5 & IP6 on x & y beam manifolds to measure rate of pressure rise (looks like x is rising 2-3x more than y)
• Hard closed GV5 & GV7 to confirm no help from adjacent cryopump (no change in rate of rise)
  • We found that hard closing GV5 does not change status on MEDM from yellow to red (FRS 8142)
  • GV7 hard closed fast at around 20 psi
  • GV5 wouldn't hard close at maxed out 80 psi, so we partially re-opened to re-seat the gate. Then it hard closed around 40 psi with a very loud bang
• Valved in x & y beam manifold turbos to trend the pressure drop. Inlet pressures (foreline pressures) before and after valving in:
  • Y:  valve closed: 5.2e-8 Torr (7.6e-3 Torr); valve open: 9.0e-8 Torr (7.6e-3 Torr)
  • X: valve closed: 2.2e-9 Torr (1.0e-3 Torr); valve open:  5.2e-8 Torr (1.0e-3 Torr)
  • Note:  X turbo is being backed by leak checker equipped with a turbo; Y turbo is backed by scroll only
  • Attached is trend so far (log scale & linear scale)
• NOTE that PT-180 was baked by Kyle many months ago when we were investigating why these two new hot cathode ion gauges drift up in pressure while the cold cathode (PT-120) doesn't follow same trend. Do we trust the gauges??
• Chris will refill the three empty He gas bottles so we can resume spraying the tube tomorrow

J. Kissel

As instructed (see LHO aLOG 35977), Nutsinee and Corey reconfigured the ETM ESD systems in such a way that I thought might help mitigate charge accumulation while we're venting essentially immediately after we intentionally broke lock on May 8th 2017 at ~15:15 UTC. 

I've measured charge today, hoping to see a noticeable improvement, if not at least a change in the trend. 

For ETMX: We a change in the charge accumulation, if not an improvement. GOOD!

for ETMY: We do not see a noticeable charge in the accumulation rate... yet! The optical lever's report of rotational actuation strength shows the effective bias voltage continues to trend negative. HOWEVER, don't yet be discouraged: historically, when we flip the bias voltage, the first data point is confusing. One needs several weeks worth of trend to confirm an accumulation rate and direction.

Assuming the IFO is still down, we may take another measurement on Friday to help fill out the data set, to make sure we're doing the right thing.

Covering for Corey while he works on 3IFO at the VPW.

- Jenne, Vaishali and Kiwamu working on locking IMC in control room
- Aidan and TJ working on HWS in control room
- Apollo working on FMCS at end X

J. Kissel

Charge measurements prefer the test mass suspension's optical levers be very well centered on their QPDs before starting. As I was centering the optics manually this morning, I found the H1 SUS ETMY suspension suspiciously low (pointed down) in pitch. After some investigation, I've learned that we're taking the opportunity during the break to upgrade the EY VEA HVAC system. After trending the optical lever, the L2 OSEMs in Pitch, and M0 OSEM in Vertical, coupled with the (formerly correct?) channel for temperature, I can see some sort of obvious, large, drift in the suspension that would be easily explained by VEA temperature excursions.

I merely post this as a reminder that once we get the VEA temperature back under control -- and back to the VEA's former temperature set point, we'll need to re-assess ETMY and TMSY suspension alignments. 

For now, I've left ETMY with its alignment centered on the optical lever.

Without the ALS green beam leaking onto the HWS table, it is a much more laborious exercise to align the HWS beams. However, the process involves these steps:

1. Find the HWS return beam:
   1. Coarsely align the HWS beam to the center of the first in-vacuum lens by using an IR camera and counting the number of turns on the upper periscope mirror required to scan the beam across the full aperture of the in-vacuum lens, then move it half that amount
   2. Scan SR3 slowly +/- 2mrad in PITCH and YAW and measure the return power on the HWS CCD camera. The oscillation frequencies of PIT and YAW should not be multiples of each other. (Make sure SR3 cage servo is off).
2. Once HWS return beam is located, gradually return SR3 to its nominal IFO-aligned position while using the upper periscope mirror to keep the HWS return beam on the HWS CCD
3. Once SR3 is in its nominal position, use the upper and lower periscope mirrors to align the HWS return beam so that it remains on the HWS CCD and also is centered on the pre-aligned irises on the table (pre-aligned to the outgoing beam). To do this, open and close the iris and note the diameter at which the return beam is occluded. Iteratively adjust the upper and lower periscope mirrors (while keeping the return beam on the HWS CCD) so that this diameter is decreased.
4. Align the last HWS mirror so that the return beam is centered on the HWS CCD
5. Move the HWS to the conjugate plane of the ITM: Inject a YAW oscillation into the ITM and measure the beam displacement oscillation on the HWS CCD. Adjust the position of the HWS until this is minimized.

As of today, we've injected an SR3 oscillation a few times and successfully located the HWSY return beam but not the HWSX return beam. At this point, my suspicion is that ITMX has not returned to its nominal pre-vent alignment with enough precision to get a return beam at all on HWSX. We currently have not ITM OpLevs to check this.

This morning, we are going to proceed with getting the HWSY return beam aligned while Jenne and Co. see if they can get the DRMI aligned.

Bottom plots show HWSX (left) and HWSY (right) return intensities vs SR3 PIT and YAW SR3-M1-TEST input values

WP 6625
ECR E1600210

The Kepco HV power supplies for ITMX, ITMY, and ETMX were replaced with an equivalent linear supply made by Mid-Eastern Industries Inc. Power supplies for ETMY were replaced on Dec 5 2016. Alog 32186.

New units installed:
S1700114 & S1700115 ITMY/ITMX
S1700116 & S1700117 ETMX
S1610431 & S1610433 ETMY