Sebastien, Slawek, Travis

We pulled out the remaining jigs from the ETMX chamber this afternoon. All the AMDs are still in place in their nominal locations, with what looks like homogeneous bond (Slawek will post pictures later). No issue to report.

This was the last chamber: all the test masses are now equipped with 4 AMDs. Big thanks to the team for the warm welcome and the help.

TITLE: 05/18 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:

HAM6 is now sealed up & there are plans to pump on Monday.
LOG:

• 15:18 APS arriving on site to work at the LSB. (Richard notified)
• Investigating ground loop issues for HAM6's ZM1 (Fil, TJ)
• 16:54 MY VAC work (WP7572) [Chandra, Gerardo]
  • 21:00 Returning to MY (Chandra)
• 17:10-17:49 Working at IOT2 (Robert)
• 17:49 Mid stations trip for PEM/Vault work (Marc)
• 17:49-1800 LVEA transitioning to SAFE (Peter)
• 18:00-19:00 HAM6 N. door install (Mark & Tyler)
• 18:17 Disconnecting ISCT6 fibers (Daniel)
• 19:09-19:34 Grabbing parts at EX (Travis)
• 19:49 Transitioning LVEA to Laser HAZARD (Corey)
• 20:06 Looking at SRM Heater Laser (DanB, JeffJ)
• 21:08-22:15 EX AMD break down/removal of equipment (Seb, Slawek, Travis)
• 21:08 IOT2 work (Robert)
• 22:14 Vault & MX work/trip (Fil, Marc)
• 22:28 EX in-chamber photos (Robert)

Completed WP 7574. No issues encountered. Burtrestored to 6 AM this morning. Some cold cathodes need to refire.

Follow up from Gregs alog41958.

I went through the code and added an INIT state, and then cleaned up a few bits to go with pep8 standards. Testing went well so I added them to the Guardian Overview (see attached if you care).

The LVEA has transitioned to LASER HAZARD.

This is covered by WP#7577.

After Richard M. received a verbal YES from Peter K., I removed a Lock/Tag on the PSL Shutter & moved the shutter from the closed to the OPEN state.  The Key/Lock/Tag were pulled and returned to the LOCKOUT STATION/Key Box.

Chandra, Dave:

MY PT245 vacuum gauge's alarm level was reduced to 5.0e-09 Torr and the code was restarted.

-<Channel name="H0:VAC-MY_Y4_PT245B_PRESS_TORR" low="1.0e-10" high="5.0e-05" description="VE gauge, MY CP4, CC">
+<Channel name="H0:VAC-MY_Y4_PT245B_PRESS_TORR" low="1.0e-10" high="5.0e-09" description="VE gauge, MY CP4, CC">
 

TJ, Daniel and I digested transfer functions on the OPO, OMC, and ZM1 suspensions.

The OMC looks fine - all traces match previous plots.

The OPO does not have great coherence on some of the plots, but I am working on tuning those here and there.  The coherence looks ok where it matters, and peaks line up with the last in-air measurements (~4/26).  Maybe we have more purge now than when those emasurements were taken.  Note, the coherence from then wasn't great either.

The ZM1 which is shorting on Pin 2 at the sat amp in the rack (first OSEM LED cathode) does not show up as anything bad on the TFs.  TF plots match previous references, again with some drops of coherence here and there.  Note, the spectra does not show any crazy comb indicative of agregious ground loops.  We decided that since we don't know where this single short is or why it randomly appeared when we did not topuch anything on this path, we will leave it for now.  We will recheck all ground loops on this chamber at more regular intervals to see if there is merit in our feelings that ground loops are intermittent.

ISCT6 is being moved out of the way (with Daniel's help) and Mark, Tyler, and Chris will get the N door on. (South door was reinstalled on Wed).

Final TFs to be taken after pumping has started next week.

The LVEA has transitioned to  LASER SAFE 

This completes work permit 7568.

Work covered by work permit 7575.

After Hugh's HEPI-Oplev yaw decoupling, I wanted to look at HEPI Y - ISI RX/RY tilt decoupling on this chamber. I used the same approach we've used in the past on the ISIs, using the ISI T240s as a witness. I drove HEPI at low frequency, with the ISI isolated with high blends to lock the stages to HEPI. If the there is any Y to RX/RY coupling it shows up as a g/w^2 tilt in the HEPI Y IPS to ISI X/Y T240 transfer function.  For the T240 X dof, I saw that pretty clearly. For Y, the low frequency component is more like 1/f-f^1.5, instead of 1/f^2.

The attached plot shows the transfer functions (before & after) from HEPI Y IPS to the ISI X/Y T240s. In order to get the coefficient for the correction, the transfer functions need to be put into tilt units (dividing by g/w^2) and the T240s are put into displacement, so the magnitude y-axis is rad/m-rthz. After getting the units right, I just got an eyeball average of the flat, low frequency component for the Y-RY transfer function. The difference between the lower blue (measured before the correction) and yellow (measured after) curves are the improvement I was able to get. I looked at the IPS Y to oplev yaw and pitch tfs to see if there was any difference, but there was no change.

Yesterday I tried to isolate the daqd process from other system processes by giving it exclusive access to most of the cores on the system by using the cpuset program.  I was not able to move all processes off the cores, but it reduced scheduling pressure on 11 of the cores to allow the daqd more cpu time.

We let it run overnight.  The attached plot has 3 runs:

 * left - The original code.
 * middle - The code with faster checksumming.
 * right - The code with faster checksumming and an isolated process.

The retransmit rate was reduced by more that 50%.  Today I will work on how automate the setup I ran h1fw2 in yesterday.

With the reduction of retransmit requests that we are seeing on h1fw2, I will be filing a work permit to do this work on h1fw0 next week.

TITLE: 05/18 Day Shift: 15:00-23:00 UTC (08:00-16:00 PST), all times posted in UTC
STATE of H1: Planned Engineering
OUTGOING OPERATOR: None
CURRENT ENVIRONMENT:
    Wind: 14mph Gusts, 10mph 5min avg
    Primary useism: 0.07 μm/s
    Secondary useism: 0.07 μm/s
QUICK SUMMARY:

Quiet morning thus far with technical cleaning team only activity in LVEA.  Ran through the morning items from Ops Checksheet (only items of note were:  OPO was tripped, so untripped watchdog.  Dust Monitor Check looks "OK".  Dust monitor alarm at HAM5 (prob due to cleaning), HEPI EX diff pressure is INVALID.  Vacuum has lots of (usual?) alarms.)

Around 4:30 pm local time the turbo pump on CP4 tripped for unknown reason. Coincidentally EY chiller pump tripped around the same time. Unfortunately a portion of the foreline (upstream of safety valve) back streamed through the turbo. Thankfully Gerardo was still on site and rushed to MY to turn it back on. But unfortunately the RGA was valved in. We will take a scan tomorrow to assess and then install the small IP at bottom of CP and reconnect the cold cathode gauge so we can leave the turbo valved out. Pressure currently at 2e-8 Torr.

Chris, Mark, Tyler, Gerardo

Removed HAM 6 north and south doors Wednesday morning and tacked south door back on in the afternoon. Today south door was torqued. North door still off.

This morning, CoreyG, Marek, DanB and I went to EX and installed the last 2 baffle panels on the PCALX periscope. Marek & Corey stayed outside the chamber, used the top gun on the panels and installed fasteners in. Dan and I waited inside, and put screw caps on while they were working outside. No real issues. All hardware has been installed, including screw caps and barrel baffle fastener swap (for new coated hardware, this had been done a couple weeks ago). Corey took some photos, hopefully he'll post.