{Kyle, Tyler, Chandra}

In an attempt to find air leak at EX and based on some aLOGs from summer 2018 (43165 & 43184), we had reason to believe that IP12 may be leaking and so today we isolated IP12 + chevron baffle from main volume and leak checked with a background of 1.5e-9 Torr-L/s of He. We sprayed ample amounts of He and saw no rise in signal.

We also sprayed the beamtube side flange of isolation GV while Jeff Jones remotely watched the RGA screen in control room, running in MID mode with new Labview based software with no change in AMU 4. This test is inconclusive, however, because we were opened to BT.

We suspect the leak is in the e-7 Torr-L/s range.

Next opportunity to leak check with BT GV closed is March 3 when we replace the maglev turbo.

Work Permits Executed:

• 8530 - Bolt removal; HAMs 7&8
• 8528 - PEM work @ end stations
• 8529 - MSA "No Trespassing" sign work
• 8532 - Fume Hood cleaning'
• 8535 - EX; Valve out IP 12 / connect leak checker
• 8531 - Guardian IFO_NOTIFY work
• 8534 - SEI eq mode work

Vendors:

• 16:19 Paradise Water
• 16:37 Uni-First
• Norco LN₂ delivery ⇒ CP8 EX
• Norco LN₂ delivery ⇒ CP1 CSY

Recovery:

• 20:00 SEI_CONFIG back to WINDY
• 20:04 All (L)VEAs swept for Observing
• 21:14 Sheila done with new CHECK_MICH_FRINGES code testing
• 21:14 Re-locking begins
• 21:35 Fume hoods switched off for observing
• 22:25 H1 Back to Observing

Tyler G., Kyle R.

Tyler also installed the bellows retractors (finger tight)

One of the more common manual interventions that operators have been doing is that when PRMI won't lock they use check_MICH_FRINGES to see the dark michelson and manually adjust the beam splitter.  (This seems to account for most of the DRMI interventions lately).  Jenne and I had talked about automating this, today I took some time during maintence to implement it.  

For operators:

• The guardian will (as before) attempt to lock DRMI for 5 minutes, if it hasn't locked after 5 minutes it will try to lock PRMI.  If that hasn't locked after 5 minutes, It will change to CHECK_MICH_FRINGES.
• CHECK_MICH_FRINGES is now using the ALIGN_IFO node instead of directly locking things itself, it will increase the power into the IMC to 10W, then lock the bright Michelson, and use the dither alignment to lock it.  This is the same guardian code which is used in initial alignment.  
• There is a new state called MICH_OFFLOADED in ISC_LOCK, which will happen right after CHECK_MICH_FRINGES, which turns off the AS centering loops, turns off the MICH loop, and turns the laser power back to 2W for PRMI and DRMI acquisition. 
• The gaurdian should then move on to PRMI and then DRMI as normal. 

Details about the guardian change:

• I wanted to avoid copying and pasting from the inital alignment guardians into ISC_LOCK, so I added an additional path in ALIGN_IFO which is nearly a copy of the MICH_BRIGHT_ALIGN path that we currently use.  To do this I made most of the states in this path into generators, with two instances, one with the old state names and numbers which we still use for inital alignment.  The intial alignment has been tested and is working as it used to.
• I added a state in the inital alignment mich branch called set_sus_for_MICH, this used to be done in PREP_FOR_MICH but I needed to separate it out so that is can be different when we are locking FPMI than when we are locking just the michelson.  
• I made two changes to the DOWN state in ALIGN_IFO, to try to preserve the ALS lock when we run this down.  We set ezca['IMC-MCL_GAIN'] = 1, I added an if statement so that this is not done if ALS_COMM is in the IR_FOUND state.  We also set the MICH gain to 0 with 0 ramp time, I changed this to a 3 second ramp.  
• We have been able to keep ALS locked while this state runs down several times now.  
• We might loose the ALS lock if the michelson looses lock here, but it has stayed locked several times as I tried this. 
• We did this on the way to relocking today, and saw that the resulting PRMI alignment wasn't very good, but it was good enough for PRMI to lock and the ASC to work work.  We have been suspicous that we aren't getting great michelson alignments from initial alignment, see Jenne's alog and my comment from earlier today: 54906
• These changes are revision 20978

If for some reason this change is a problem, it can be avoided by setting the timer of how long to wait in ACQUIRE_PRMI before trying CHECK_MICH to be very long.  This timer is on line 966 of ISC_LOCK, and is currently 300 seconds, but you could set it to 3000 and reload ISC_LOCK if there is a problem with these states. 

The following modifications were made at EX to help with the ongoing noise hunting investigation.

1. Baffle Photodiode Amplifier moved from SUS-R1 to FAC-R1
2. Baffle Photodiode Amplifier powered down
3. Beckhoff hub isolated from rack
4. ESD current limit resistor box removed and SHV barrels installed

The removal of the current limit resistor should have no impact. The installed ETM Low Noise ESD Driver Chassis (D1500129) has built-in current limit protection.
The Baffle Photodiode Amplifier unit was powered down to see if the Beckhoff terminal might be a noise source. Unit at EX is normally not used to lock the Interferometer. Unit can be powered back on by reconnecting the ±24V power cable.

F. Clara, R. Mccarthy, R. Schofield

EY was swept; because we are planning to do some shaking later this week, the shaker amp is on.

Ed called, said the PSL quad display flashed and the PMC had reacquired lock on a non-00 mode.  The usual fix for this is to raise the resonant condition of the locking loop so it won't lock on a non-00 mode, but for some reason the PMC doesn't like it when the resonant condition is raised; it will have a very hard time locking (this is one of the those small, rarely-occurring instances that we haven't had the time to fully investigate as it happens so rarely).  In this instance, I manually unlocked and relocked the PMC a couple times and it locked on a 00 mode with no issues.

The FSS RefCav relocked almost immediately upon reactivating the autolocker, and the PSL_FSS guardian node functioned as we intended with our recent mod.

Upon relocking the ISS, the diffracted power dropped to <1% and the loop would unlock itself (as it does when the diffracted power gets too low), then this behavior would repeat; the fix was simply to raise the ISS refsignal until the loop became stable (in this case, a small bump to -1.97V from -1.99V), then slowly lower until the diffracted power is within the desired range (in the majority of cases, like this one today, the refsignal will return to its original value).

Unclear at this time why the PMC unlocked.

The Pcal team swept after finishing our work, and the VAC team will unplug what they plug in and turn off the lights when they're finished

The ETMY diurnal drift seems more pronounced than the ETMXfor both Pitch and YAW. Worse for Pit, is there a reason for that? Curious.

Shifter: Adrian Helmling-Cornell

ahelmlin@uoregon.edu

Highlights from my DQ shift this past week:

• Observing for 81.0% of the week
• Observing just under 120 Mpc every day
  • Range was really stationary most days
• Two glitchy periods on Monday that didn't match up with the usual seismic suspects
• 90 Hz noise, noted last week, was present on Monday
  • Bruco results inconclusive
• Squeezer/FSS stability problems caused more downtime
• EX PEM chassis channel showing up in HVeto
• Large earthquake Sunday causes brief range drop, lots of glitches, but stayed in observing

For the full report see: https://wiki.ligo.org/DetChar/DataQuality/DQShiftLHO20200203

   All three Dust Monitor Vacuum Pumps are running well. 
   Made slight adjustment in vacuum pressure at End-Y and the CS. 
   All temperatures were normal. 
   The mufflers were clear of carbon dust.

Closing FAMIS #13006 

   Checked all three HEPI pump skids.
CS - 6 5/16" - Down 1/16 from last check. No visible leaks noted on any of the four skids.
EX - 7 13/16" - Down 1/16 from last check. No visible leaks noted on the pump skid.
EY - 8 14/16 - No change from last check. No new visible leaks noted on the pump skid. 

Closing FAMIS #13496

Added a new Guardian node that will monitor the relocking status and move to a state that Daves phone alert system will then alert from. We still need some time to test the logic of when to alert, but for the most part it follows the regular T1900725 Operator Thresholds for H1 Intervention document as well as checking for some other major errors. During this testing time we will not be sending out actual alerts.

This node was added to the top of the Guardian overviews and I checked that all nodes are on them.

I reset both PSL power watchdogs a 17:54 UTC (9:54 PST); this completes FAMIS 10749.

Last week Jenne realized that when I moved the MOVE_SPOTS state Jan 1st, I copied some things that inadventently were causing a 2 minute pause 54949 54219. We've had 8 locklosses from MOVE_SPOTS since these accidental pauses were removed, but only had 3 locklosses in this state since I moved it in January.  This morning Patrick had 3 locklosses from this state.  The attached screenshot shows that the servo to TMS seems to be working fine with Jenne's change, as you would expect.  

However, we only had three locklosses in this state between Jan 1st and Feb 6th, but we've had 8 locklosses from this state in the last 5 days, including 3 that Patrick had this morning.  It might be that the unintentional pause here was needed to let the ASC converge after the power up before moving the spots.  I added a 2 minute timer where the TMS servo will run but the A2L gains will not get changed for the first 2 minutes in this state, we will see if this fixes the problem. 

[Jenne, Niko]

Last week I discovered that the MICH_BRIGHT_ALIGN state of initial alignment wasn't waiting long enough (or waiting at all) for convergence (alog 54802).

Today Niko changed the convergence thresholds from 10 to 0.5, and that indeed made the initial alignment guardian wait until the ADS servos were closer to ready before offloading.

However, I don't think that the BS ADS setpoints are actually where we want them.  After initial alignment was complete, Niko went to MICH_DARK_LOCKED and hand adjusted the BS since it was clearly not well aligned.  I then turned on the ADS dither lines (but not the servos), and saw the lines quite clearly in the H1:ASC-AS_A_DC_NSUM_OUT_DQ (although I did not check where they were in MICH Bright, since it was time to head back to Observing).  The BS M2 Y2L gain is currently set to 11, and was last changed in ~August 2018 when we were doing TCS tests to check the contrast defect.  Before then it had smaller but still nonzero values. 

Next week during maintenance I'd like to revisit this by hand-aligning the BS in MICH_DARK_LOCKED, and then using that alignment in MICH_BRIGHT, and set the A2L gains for BS to minimize the lines in the ADS error signals.  We may want to revert to the current NomLowNoise values of P2L=0, Y2L=11 in the DOWN state if those are indeed giving us the best A2L decoupling at full lock, but they seem to not be putting us in a good spot for acquisition.