J. Oberling, E. Merilh

Just a couple of quick items for today's maintenance.

FSS EOM Cable Re-Termination

Peter had requested this a few weeks ago after finding some weirdness with the FSS EOM cable.  I disabled the FSS via the autolocker, had to manually disable the main FSS loop and the temperature loop (these should default to OFF so the FSS is disabled when the autolocker is disabled), unplugged the TTFSS (maybe not necessary, but done out of an abundance of caution), and fed the EOM cable out of the enclosure so Ed could re-terminate it (involves solder so we definitely did not want to do that in the enclosure).  That done, everything was wired back up and the FSS was locked using only the autolocker; it locked almost right away with zero issues.

PMC and RefCav Beam Alignment Tweak

Once the enclosure temperature had settled after the incursion for the FSS EOM cable re-termination, I briefly tweaked the beam alignment into both the PMC and FSS RefCav; this was done with the ISS OFF (because the ISS will fight any improvements in PMC transmission, since as far as it is concerned the power is increasing when it shouldn't).  That complete, I turned the ISS back ON; it is currently diffracting right around 2%.  With the ISS ON, the PMC is now transmitting 54.7W and reflecting 10.0W; the FSS TPD is now reading ~4.3V.

Other small things

I was asked to double check that the DBB was in fact OFF.  There is no power going to any of the DBB electronics in the PSL rack, everything is unplugged.  The DBB MEDM screen is reading how it normally does when the electronics have been powered off.  The DBB is OFF.

I also set the flow sensor trip point for O3 to 0.8 lpm.  The flows are currently reading 1.5 lpm, 1.5 lpm, and 1.8 lpm for the FE, Power Meter, and 70W amp cooling circuits, respectively.

Rick, Niko,

Performed Pcal Tx maintenance at EY this morning. Laser output power is at a reasonable level, but the AOM diffraction efficiency is a good deal worse than we expect it to be. We would like to take a future maintenance day to tune up the AOM.

(OFS Open Loop Transfer Function Bode plot not included, did not save correctly to the flash drive)

Ed, Fil

Both end stations were swept as per LVEASweepChecklist. Checklist will be slightly edited for some ambiguities:

• Phones unplugged & batteries pulled from handsets (Phone locations here)

  • includes both electrical connection(transmitter and other base-station functions) as well as the actual telephone connection from the block as to prevent ringing.
• Power down the intercom via blue box in Airhandler room
  • these are actually small BLACK boxes marked VALCOM. They are plugged/screwed into a wall socket and must be laid on some support as to not let them hang on their wires.

Rick, Niko,

Performed Pcal Tx maintenance at EX this morning. AOM diffraction efficiency and laser power are within an acceptable range of the last maintenance measurement, taken 08/03/2018.

The corner station PEM model, h1pemcs is supposed to have all the DAC channels on the 18-bit DAC in the h1oaf0 computer. These had been stolen some time ago by a "compact BRS" model. Checking with Jenne, this was decommissioned some time ago, so I reconnected the 0, 1, 2, 3 DAC channels back to h1pemcs. I restarted the model, did not require daqd restart.

Now these channels can be used for whatever injections, connecting to the 18-bit DAC in the PEM rack. Channels such as H1:PEM-CS_GDS_<#>_EXC, where # can be 0 thru 6, as labeled on the front of the chassis.

On 3/13/19 the whitening readback for ASC-REFL_A_RF45 switched state for unknown reasons. This could indicate that filter 3 for one of the segments is engaged in analog but not digital.

OPLEV Charge measurements for the ETMX was performed today. Attached file shows the analysis performed on the MATLAB. The long term trend of the charge effective bias is consistent with the previous values and no large change is observed. 

SDF showed that the biased voltage (ETMX) was turned OFF, Jenne showed me how to turn it back ON. All other values were restored for lock acquisition. 

Used two layers of the original fabric on the south section (15' wide.)  We may want to run the production fence cladding to the ground for improved performance and we want to see if tumbleweed accumulation is really a big problem.  So far we have not had any tumbleweeds collecting on the fence with a gap from the ground to ~4-5' but that gap may cause turbulence and wind speed increases.

Cable cleanup in squeezer rack:

• The delay line phase shifter for CLF, spare, LO and homodyne are all connected in series, some with coaxial adapters and BNC cables (one was 75 Ohm?!). Replaced them with proper TNC cables. Thsi will change the squeezer phase by a small amount.
• Strangely the LO and homodyne demodulator LOs were driven through a splitter . Removed the splitter, and re-connected the two original LO cables. This will also change the squeezer angle.
• The PSL VCO feed forward was disconnected. Added a cable from the 3rd DAC output to the excitation input of the VCO using a Pomona box with a 1Hz pole.
• Reconnected the excitation cables for all servo boards.
• Removed a rat's nest of test and diagnostics cables from the squeezer rack.
• Removed cabling for additional Thorlabs PD that is no longer needed. The feedthrough adapter panel was reattached to the table enclosure.
• Moved one SHG cable that was flung across the floor to ISCT6 into the cable tray.
• There is an unused PFD chassis at the bottom of the rack which could be powered off. This will require the PFD to been taken out of the TwinCAT error handler.

Laser Locking:

• New TwinCAT code for addressing problem reported in alog 47589.

Last night TJ and I tried some TCS tuning of CO2X to see if we could fix some of the high frequency noise couplings. Things we learnt:

• ADS doesn't seem to like the same scale of TCS change and I had been doing before. The other night I changed SR3 heater with the 36W test and it started trending away. Then last night when I increased the CO2 it also got unhappy and got itself into a glacially paced oscillation. It was an odd oscillation, it seemed to get a strong kick each time it got close to zero... I left it on at the time as each time it looked like it was sorting itself out, eventually when the CO2X heating had cooled down it was fine.
• The violin mode last night seemed to be ringing up since the start of the lock before any TCS changes were made last night
• Increased CO2X from 0.6W to 1W (the other night I manged to push this up to 1.2W). During this time:
  • RF18, RF90, kappa_c decreased
  • PRG, cavity pole increased
  • Decreasing lines: 9MHz RIN, ~70Hz and 3200Hz intensity noise, 4500Hz frequency noise
  • Increasing line: ~70Hz frequency noise
• Decreased CO2X from 0.6W to 0.4W
  • TJ thinks things were getting more unstable
  • ADS looked ok
  • ASC: DHARD P/Y and CSOFT P look like they were getting noisier. The noise didn't reduce after turning the CO2 backup again.

I haven't demodulated all the lines and data yet but I'll make plots later.

Overall the noise couplings got better with more CO2X, similar behaviour to what we saw at 30W as we're giving a CPX a more positive lens to match the extra heating in ITMY. This time we did see some changes in the frequency noise coupling in the bucket, previously we did not see that. Although the noise couplings got better the sideband matching in PRCL/SRCL got worse. Both RF18/90 were reducing and AS_C sum was increasing. PRCL to arm matching seemed to get slightly better though as PRG increased a small amount, ~0.1.

Less CO2X just made everything worse, apart from frequency noise coupling in the bucket.

Patrick, Filiberto

Ran svn update on h1ecatx1
Ran svn update on h1ecaty1
Disabled and cleared TortoiseSVN stored passwords on h1ecatx1 and h1ecaty1

h1ecatx1:
Updated from source
Rebuilt PLC1, PLC2, and PLC3 in target directory
Rescanned PLC1, PLC2, and PLC3 in system manager in target directory
Linked Channel 4 of ALS Laser Table Relay 1 (EP2624-0002) to TcsHWSEOut.SledShutDown in system manager in target directory
Activated configuration
Filiberto swapped the patch cable inside the end X illuminator chassis for an Ethernet patch cable
Restarted everything
Everything is back in OP and the glitches as noted in alog 47502 have disappeared. The CRC errors have also cleared.

   All three dust monitor vacuum pumps (EX, EY, CS) are working within specifications. Made slight pressures adjustments to all three pumps. All temperatures were under 150f. 

   The carbon dust buildup on the CS vacuum pump muffler is still present but not growing from the last check (2 weeks ago). Will keep an eye on the CS pump for indications of vane failure. There is a rebuild kit ready to go. 

   Closing FAMIS #8355

BruCo scan here for last night lock: https://ldas-jobs.ligo.caltech.edu/~gabriele.vajente/bruco_lho_1237033818/

Some highlights:

• INP1_Y at ~ 20-30 Hz (plot 1) also visible in IMC yaw (plot 5)
• the bump at ~48 Hz is visible also in REFL_B_RF9 (plot 2)
• Below ~20 Hz OMC_RIN (but is this just another witness of DARM motion?) (plot 3)
• At 480 Hz bump, coherence with IMC WFS stuff (plot 4)
• PRCL is close between 30 and 150 Hz (plot 6)

The servo board for the IMC (S/N S1102626) was replaced with the modified spare (S/N S1102627). This implements E1800338-v3 and ECR E1900059.

During today's maintenance, CDSSSH (Remote Login Machine for CDS) was successfully upgraded from Debian 8 (Jessie) to Debian 9 (Stretch) without incident, after the upgrade process, I tested the connection and logged into CDS successfully. Also as part of the maintenance I updated and rebooted EPICS-GW which provides internal epics channel connectivity to the Control Room, During the reboot not interference with the Control Room activities was reported or seen. Also all Workstation and main servers where updated as well. 
Since the Control Room is now in 24 hours operation setting zotws3 (the main operator workstations) was removed from the scheduled reboot list. Please operators be advice that if reboot is required for kernel or other major updates, manually rebooting ZOTWS3 will be requested as possible.

TITLE: 03/19 Owl Shift: 07:00-15:00 UTC (00:00-08:00 PST), all times posted in UTC
STATE of H1: Observing at 101Mpc
INCOMING OPERATOR: Jim
SHIFT SUMMARY:Some trouble staying in Observing from SDF diffs that would spontaneously pop up faster than they can be tracked, and from  violin modes ringing up. There was some TCSX tuning going on which I'm sure did not help the violin modes.
LOG:

• 0857 - Out of Observing from SQZ
• 0859 - Back to Observing
• 0926 - Out of Observing from violins
• 1020 - Observing
• 1024 - CO2X 0.6W -> 0.5W
• 1122 - CO2X 0.5W -> 0.4W
• 1206 - Out of Observing from unknown SDF h1sysecatc1plc3
• 1207 - CO2X back to 0.6W, seemed to be making things a bit more unstable
• 1208 - Observing
• 1232 - Out of Observing
• 1321 - Observing
• 1458 Carlos restarting EPICS gateway