Completed WP 6579 and then some.

• Ran Kobelco purge air unit (DP measured -43.7degC)
• Ran QDP80 (#2) roughing pump
• Spun up turbos on X & Y beam manifolds successfully & swapped out battery packs on both

*left three turbo stations and Kobelco energized, water still valved into QDP80 (#2) for cooling

Follow-up maintenance items:

• QDP80 (#1) needs oil before vent
• Green indicator light on QDP80 (#2) pump is burned out

This completes WP #6587

   Checked and adjusted the air bypass on the dust monitor vacuum pumps in the CS and at both ends. All pumps are OK, pressures and temperatures are within normal limits. The pump at End-Y is a bit noisy will keep an eye on it and if it gets worse will rebuild it. Closed out FAMIS 7512. 

• Robert
• Jenne
• Fil
• Christine and Karen

• DaveB

• Kyle

Completed maintenance by replacing the one way valve that compressor #2 needed.

Work done under WP 6541, which is now closed.

Pulled cables for RBS ion pump power supplies signal for both X-End and Y-end stations.

They will be terminated later.

Work done under WP#6585.

[Jenne, Vaishali, Karl, Heather]

We have removed all cabling and all L4Cs that were in the beergarden and potentially in the way of the vent work (incl. prep). 

Since work was ongoing on the HWS table, we have not yet removed the ~4 sensors that are in the vicinity of the north HAM4 door.  We can do this opportunistically during the week if the IFO is offline for some reason, otherwise we'll do it next Tuesday. 

[Greg Mendell, Aaron Viets]

The GDS calibration pipelines were restarted at GPS time 1176571587. The output, latency, and CPU usage looks as expected. The command line arguments and filters have not changed from last week, as the same filters and options will work with the older code.

Two maintenance items and one FAMIS task on the docket today: increase HPO pump diode currents and tweaking of the beam alignment into the PMC, and the weekly FAMIS PSL power watchdog reset.  The following work was done with the ISS OFF.

HPO Pump Diode Currents

I increased the HPO pump diode currents and temperature tuned the diodes.  A summary of the new and old pump diode currents is below in Table 1.  Diode Box #1 continues to decay faster than the other 3 diode boxes.  We want to replace an in-service diode box once its operating current exceeds 90% of its maximum.  These DBs max out at 60A, so the target for replacement is 54A of operating current.  Using this as a guideline, DB1 is beginning to get close to replacement.

Following this, I temperature tuned the diodes to maximize the output power of the HPO.  A summary of the temperature changes is listed below in Table 2.

After this work, the HPO is now outputting 169.2 W.

PMC Beam Alignment Tweak

Next, with the ISS still off, I tweaked the beam alignment into the PMC.  Only small tweaks were required to maximize the transmitted power.  Unfortunately I was not able to recover as much transmitted power as usual; last time I tweaked this alignment, with the ISS turned back on the PMC reflected power was ~14W and the transmitted power was ~65 W.  Now the best I could do, with the ISS turned back on, is 16.2W of reflected power and 63.9W of transmitted power.  To me, this indicates a slight mode mismatch, which requires a PSL incursion to correct.  For now, and for the scope of this work permit, the PMC transmitted power is >60W, which is our target for PMC transmission.  This is sufficient for now, and we will plan a PSL incursion for the next maintenance window to investigate this possible mode matching issue.

This closes LHO WP 6578.

FAMIS 3646

During the course of the above work, I reset both PSL power watchdogs; this was at ~16:30 UTC (9:30 PDT).  This completes FAMIS task 3646.

TITLE: 04/18 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Preventive Maintenance
OUTGOING OPERATOR: Ed
CURRENT ENVIRONMENT:
    Wind: 12mph Gusts, 8mph 5min avg
    Primary useism: 0.01 μm/s
    Secondary useism: 0.13 μm/s
QUICK SUMMARY: all times UTC

• 15:06 - Robert used the last minutes of lock to inject at HAM6
• 15:11 - Chris to LVEA
• 15:30:
  • Nutsinee to TCSX for HWS alignment,
  • Travis to EX for Pcal calibration
  • John, site survey
  • Gerardo to EY, then EX, then MY, vaccum
  • Jason, PMC realign
  • Fil, cable pulling in LVEA, on hold due to TCSX work, requires HAM3, HAM4, and HAM5 external access, and would trip ISIs
• 15:45 - Norco #1 to EY
• 15:57 - Christine and Karen to EX and EY
• 16:00 - Norco #2 to CP2

TITLE: 04/18 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC
STATE of H1: Commissioning
INCOMING OPERATOR:Cheryl
SHIFT SUMMARY:
LOG:

12:27 Lockloss - reason unknown

• 1st attempt: some difficulty recovering x-arm
• 2nd attempt: the usual tweaking of the BS and PRMI but lost lock again after PREP_TR_CARM
• 3rd attempt: had to manually find IR Diff. Success. a2l necessary for YAW. Engaged FM6 for ETMY 10 4.75KHz violin mode.

13:32 NLN

• Leaving H1 in Commissioning for Tuesday Maintenance.
• CS ECAT PLC2 and EX ECAT PLC2 SDF Diffs need to be dealt with.

Notables:

• Decrease in power in pre-mode cleaner output by roughly 7%
• marginal upward changes in chiller pressures and headflows. Power Meter flow shows marginal decrease in flow.

Located our mobile STS2 (C) as close to the ITMY STS2 (B) as possible which means about 18in center to center.

The two graphs attached show low wind (~5mph) and high wind (~20mph) graphs of ASD and coherence between the two huddling STSs.  Good coherence moves well down during the windy conditions as the ground motion increases to above the instrument noise.  Coherence above 0.9 moves from 50ish mHz to 5 or 10mHz (depending on dof.)  Tomorrow I'll move the roaming machine to around BSC8 and then wait for calm and wind.

Starting CP3 fill. LLCV enabled. LLCV set to manual control. LLCV set to 50% open. Fill completed in 1200 seconds. LLCV set back to 20.0% open.
Starting CP4 fill. LLCV enabled. LLCV set to manual control. LLCV set to 70% open. Fill completed in 1484 seconds. LLCV set back to 38.0% open.

This morning I swapped the ITMy oplev laser, per LHO WP 6565.  This was in response to this alog from K. Venkateswara and J. Kissel, indicating an ~0.44 Hz feature on the ITMy oplev (that showed up after the laser swap on March 7th) was possibly due to an issue with the laser and causing range issues.  The old laser SN was 189-1, the new laser SN is 191.  This laser will need a few hours to come to thermal equilibrium, once that is done I will assess whether or not the laser needs a power tweak for glitch-free operation; I will leave WP 6565 open until this is complete.