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

We found that there was a lot of stray light on HWSX and a little bit on HWSY. Detective work and general snooping found that the beam going through the main HWS BS was hitting the  rear of the BS rather than the dump behind it.

We adjusted the input alignment of the HWS beam as much as we dared, moving it away from the center of the BS closer to the top edge (in the picture shown below). More of the transmitted beam was dumped onto the beam dump behind the BS. This had the effect of reducing the scatter getting back to the Hartmann sensor by a factor of three or so. Unfortunately, should we move the beam too far across the BS surface, the concern is that the return beam from ITMX will be clipped by the beam splitter mount on transmission.

HWSX stray beam before changes to alignment on BS

The color range in this image is about 180 counts.

HWSX image after changes to alignment to BS

The color range here is about 60 counts.

HWSY stray light image

Color range is about 27 counts for HWSY.

Guide to beams on HWS BS

Input beam on HWS BS

Reflected beam from HWS BS

Beam dump behind HWS BS

Transmitted beam through BS

[John, Chandra]

Valved out IP5 and IP6 from y & x beam manifolds at 10:37 am local time. With no pumping on these volumes, we will trend the rate of rise in pressure over some time today. This will give some indication of whether we have a leak or if IP6 is going bad.

TITLE: 05/16 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
INCOMING OPERATOR: None
SHIFT SUMMARY:

Cheryl not able to make it so Nutsinee, Patrick and myself will cover.  Here is a log of the morning from ~7am -10am PDT.
LOG:

• 14:00 PSL Work:  Measuring NPRO, check water circuit, take PSL down (Peter K)
• 14:15:  Sitewide maintenance at EY, MY, & MX (Chris S)
• 14:23 LVEA work (Bubba)
• 14:30 PSL Plumbing work (Jeff B)
• 15:00 Robert in LVEA
• 15:24:  Toilet truck on site
• 15:35 Hartman Table work (Aidan & TJ)
• 15:39 Cintas for mats
• 15:40 End Station Cleaning (Christina/Karen)
• 15:43 CP4 liquid Nitrogen fill (Norco)
• 16:28 CP6 liquid Nitrogen fill (Norco)
• 16:30 Inventory checks (Betsy, Christina)
• 16:43 Leak checking IP6, for starters (Chandra/VAC)

CP4's Dewar is being filled today so I lowered the LLCV actuator value to 34% open. The other Dewar being filled is CP6 and will automatically adjust.

I will order LN2 for CP3 & CP7 on Thursday for next week's delivery.

LVEA is Laser HAZARD (transitioned yesterday).

Multiple activities are already started this morning.  

• PSL is down for plumbing work.
• Hartman table work
• Usual maintenance activities (to be summarized later).

We injected oscillations into the SR3 PIT and YAW  and measured the return power getting back to the HWS CCDs as a function of PIT/YAW position. We located the HWSY beam fairly quickly but we're having trouble locating the HWSX return beam right now. 

To be continued tomorrow ...

[Vaishali, TJ, Jenne]

In order for Team TCS to work on their stuff, we wanted to get DRMI-related optics somewhat aligned.  Vaishali put all of the optics (including end stations) back to where their local sensors (OSEMs, or OpLevs if available) said they were on 7 May 2017.  This gives us good-looking IMC refl flashes, but the mode cleaner isn't locking.  Note that during this work, we have the IMC refl camera, but we're not seeing anything on MC trans camera.  Not sure why. 

I am not seeing peaks that look nice in either of the IMC trans PDs (IM1 trans or MC2 trans), even though the flashes on the refl camera look good.  Also, we're not seeing nice dips in IMC REFL DC when we get flashes.  We've run all of the Down guardian states, so everything should be set up the way we expect.  All of the settings that I can think of look fine.  We tweaked the input PZT and MC1 to get the WFS DC values back to that May 7th time, but I'm still not seeing normal-looking things on MC trans or MC refl PDs. 

I just don't think the IMC refl beam is hitting the REFL PD, or for some other reason we're not getting a valid PDH error signal for the mode cleaner. Never having been on the IOT2L table before, I don't want to start just before having to leave, so we'll come back to this tomorrow during maintenance, or whenever we can.

NB: TJ is leaving the LVEA in laser hazard.

Attached is the pump down curve read from PT-120 on BSC3. We wait until the pressure reaches 1e-7 Torr via turbo before valving in IPs and opening beam tube gate valves. Extrapolating this curve looks like this will happen late next week.

[John, Gerardo, Chandra]

John wanted to spray some helium for himself, so we spun the x-beam manifold back up and sprayed all BSC7 conflats again, in addition to IP6 isolation GV and GV4 triple flange. He sprayed He at a KF connection at the leak checker and found a e-9 Torr-L/s range leak, which could have been what Kyle and I detected last week while testing GV7.

John noticed the BSC7 annulus ion pump's reading on front display was not clear i.e. the green LED lights were fading into 6 mA + range rather than clear-cut lit vs. non lit. He tapped on the pump and power cycled the controller a few times. It seems to be reading clearly now at 2 mA. We thought if there was an internal o-ring leak and the annulus ion pump wasn't working properly, that annulus space could be the source of pressure rise in x-beam manifold. We connected an aux turbo cart to that pump and accidentally partially vented the annulus space and then pumped it back down. No change in volume pressure though, which leads us to believe that there is no internal o-ring leak. The AIP is pumping on its own again at 2 mA.

We left the x-beam manifold turbo running and valved out for the night. IP6 is valved back in. While IP6 was valved out during leak checking, its power supply read 172 uA. When valved in, it reads 520 mA. IP5 on y-beam manifold reads about 90 uA (valved in), so we still may conclude that the reason for the pressure rise in x-beam manifold when isolated compared to y-beam manifold is due to difference in IP pumping speed. When IP6 is valved out, we expect it to read even better than IP5 valved in. One thing we didn't check is the IP flange above the gate valve. We should leak check that flange while the IP is valved in. We've sprayed it a few times now, but we always keep the IP valved out during leak checking. When IP is reopened we detect some He in -9 range (no surprise), but.....