With a woefully underestimated increase in the payload, I removed a bunch of wall mass from the ISI.  It unlocked pretty easily and then I commenced to removing more and yet more mass.  But I got there with the table locking/unlocking quite smoothly with well within spec shifts.  A 10Kg D0901075 even had to be removed from the table top.  In the end, the added payload & balance mass is lower by 52.45Kg.  I have red-lined D1001132-v3 with the changes and current mass distribution and added that to the DCC.

The ISI is unlocked with the C3 covers pulled away from the ISI.  HEPI remains locked.

Between the times of 3:24-3:27 PM PT, we saw that the laser on CO2X was turned off when we were trying to initialize CO2Y.  It's not clear exactly what caused this glitch because we had not yet started touching either system during this time frame so we're not sure if this glitch was due to a human interaction or some sort of electronics malfunction.  All we know is that the laser gate was off but that the emergency shutoff had not been pressed on either table.  Also, the laser itself was not shut off but the laser controller had somehow closed the gate.  We're still investigating this issue, we turned the laser on at 10:00 AM this morning so it had been running for about 5.5 hours or so.

08:50 Corey – Working around the squeezer area on laser enclosure
09:20 Hugh – Working on HAM4 ISI alignment & balance
09:42 Dave – At HAM4 area working on Hartman table
10:00 Jason & Betsy – HAM5 for SRM alignment
10:05 Travis & Gerardo – Working on ACB alignment
10:18 Peter – Working in the H2-PSL enclosure
12:50 Karen – Going to End-Y and Mid-Y
12:57 King Water Systems on site to work on RO system
13:17 Thomas – In and out of LVEA working on TCS
13:51 Gerardo & Travis – Working on ACB alignment 
14:22 Hugh & Scott – HAM4 ISI alignment & balance
14:30 Justin – Transition LVEA to laser hazard 
15:45 Hugh – Turned down purge air at HAM4 and HAM6

Today, Jeff is on operator duty so I tagged back in on HAM 5.  While Jason was resettting his equipment, I worked on -

- cable routing for SR3, including switching the cables in the bracket since they were mounted backwards.

- positioning all of the lower stage AOSEMs on SR3.

- removing yaw adjustment hardware and torqued remaining dog clamps.

- cable routing on SRM.

- resetting the SRM open light gains/offsets with Arnaud (and creating the safe_snap once set) - Note, this was done because it was last done on a different set of electronics/cables.  Currently, all of the OSEMs are backed out and reading open light - I'll resume setting these tomorrow.

- staging the dog clamps for the upcoming OFI and 3-baffle installs on this table.

On friday night, the wind was high(~25mph), and the arm was hard to lock. Although the angular motion of the test masses was not particularly different than on a quiet night. First attachement shows the oplev spectra from friday night, when the wind was ~25mph. second attachement shows spectra from yesterday night with a 5mph wind.

To note :

• RMS of ETMY (blue curve) in pitch and yaw are consistently higher, even though the ISIs are in the same config (level 3 controller and Tbetter blends on St1 and St2 except for Rx and Rz)
• ITMX (pink curve) seems to perform better, but it's actually because the oplev beam is offcentered from the qpd, sitting mostly on S4 quadrant. SUM is ~5900

(Stefan, Lisa, Chris)

Looking through the locked stretches from the weekend, we noticed that the ALS slow feedback -- intended to relieve the VCO control signal of low frequency seismic and tidal motion -- was failing in its mission.  What we saw is plotted in the first attachment.  The green trace shows the VCO control signal, which should be forced toward zero when the slow test-mass feedback (red trace) is enabled about halfway through the timeseries. Obviously this wasn't happening. Meanwhile the VCO frequency servo that actuates the tune slider (blue trace) was running away along with the VCO control signal. When the tune slider hits its limit at +/-5 the lock is broken.

We tracked it down to a missing integrator in the ALS-X_ARM filter bank, without which the slow loop didn't have enough oomph at DC to null the fast control signal. I think this filter was removed intentionally (but without realizing its true purpose) during some earlier automation work. We put it back and, taking advantage of the improved test mass plant inversion, we were able to increase the gain upstream (in the ALS-X_REFL_SLOW filter bank) from 1 to 30. This should help prevent the arm from being blown away by the wind.  When we lose lock the integrator is switched off by the Beckhoff, and the drive bleeds away through a 0.01Hz pole.  The improved behavior is shown in the second attachment (where the gain was cranked about 20 minutes in).

Here is the list of commissioning task for the next 7-14 days:

Green team (XY-arm):

• Hand-off to 3f lock signals.
• Common mode hand-off.
• Hand-off ALS signals to interferometer signals.
• RF phase for MICH.
• Add CM Sum in chain.
• Noise hunting.

Blue team (X/Y-arm):

• Revisit the WFS with the now improved beam quality.
• High BW feedback to input PZTs?
• EY WFS alignment sening matrix.

Red team:

• Center the red QPDs in EX/EY.

SEI/SUS team:

• EY ESD drive is broken.

In-Vacuum preperation:

• IMC/PRCL adjustment: Prepare to move MC2.
• EY ESD fix: What measurements can we do now?
• Conflat for mirror discharging.
• EX QPD centering: Can we get the beam centered?
• EY QPD centering: Will work.
• POP beamsplitter.
• Change mode of ALS/POP periscope in HAM1.
• Are all picos working?
• Test photodetector pods for leaking?

As of 12:00

PSL Status: 
SysStat: Green, except VB
Output power: 26.7w  
FRONTEND WATCH: Good
HPO WATCH: Red  

PMC:
Locked: 12min
Reflected power:   1.5w
Power Transmitted: 9.8w 
Total Power:      11.3w 

FSS:
Locked: 12min
Trans PD: 0.94v

ISS:
Diffracted power: 3.833%
Last saturation event: 12m

Jason & Betsy – SRM fine alignment at HAM5
Gerardo – Putting the OFI into storage box and fly over beam tube
Hugh – ISI balancing at HAM4
Travis – ACB balance and alignment
Richard & Filiberto – Chassis work in EE shop & cabling at HAM6
Peter & Olli – In H2-PSL working on ISS assembly
Dave – TCS Hartman table alignment

The problems we noted over the weekend with the ETM SUS (and sometimes SEI) systems tripping on lock loss (alog 11957) can maybe most accurately be characterized as a watchdog problem.  The trips are caused by large drive transients after lock loss.  It's hard to imagine that there's much we can do to prevent this from happening.  Even if the DARM (CARM, etc.) control signals could be shut off immediately, the residual impulses would still produce large impulse response in the LOCK filters in the suspensions.    We could try to shut off the drive signals in the SUS controllers, or hold the outputs at their current value, but that's a bit more difficult to implement.

In general, though, the watchdogs should probably just not be tripping on transients.  If the watchdogs were a bit smarter and only tripped on sustained saturations or oscillations, this would likely not be an issue.  I vote that we solve the problem in the watchdogs, but increasing the amount of time it takes before they trip.

Just for a bookkeeping purpose:

I recentered the beam on the IMC WFSs on this past Saturday. I used the picomotors. Both of them had been off by 0.2-ish counts in the normalized pitch and yaw.

No restarts reported.

I made a couple of improvements to the IMC guardian:

• maybe most importantly, I filled in a lot of comments and inline documentation
• cleaned up the code quite a bit
• added GuardStateDecorators for handling fault conditions and lock loss
• cleaned up edges around the FAULT state
• broke out a BOOST state from the LOCKED state

The final point was to make it so that there is no activity in the LOCKED state, so that reaching the LOCKED state means that the IMC is fully up.  In general, I think we should start making all requestable states be "idle" states in that they don't do any action other than monitoring for exit conditions.  This idea here is to make them true markers of a steady state of the system.

We end up with just two requestable states now: DOWN and LOCKED.  The DOWN state doesn't actually prevent the IMC from locking briefly, so we may want to change the DOWN state to something that actually prevents the IMC from locking.

Next, I want to make the IMC guardian the manager of the SUS_MC{1,2,3}, so IMC is actually in control of setting the MC suspensions to their ALIGNED states.  This will also allow us to achive the point above, since we can then make the DOWN state into something where the SUS are misaligned, thereby preventing the IMC from locking.

model restarts logged for Fri 16/May/2014
2014_05_16 23:12 h1fw1

No restarts reported for Saturday.

One unexpected restart of h1fw1 over the two days.

Kiwamu, Jamie, Lisa

We figured out why we couldn't reduce the CARM offset below 1kHz while keeping the PRMI locked on REFL 45 I&Q.

The REFL 45 demod phase was tuned without the arms present; it turns out that with the arms, even with a large CARM offset (1 kHz), the demod phase changes enough to make MICH very close to instability.

So, we just tuned the REFL 45 phase by monitored the MICH OL TF and the REFL 45 I/Q decoupling by looking at a PRCL line around 50 Hz.

Not a very advanced technique, but we could recover pretty easily a reasonable shape for the MICH loop and we could reduce the CARM offset.

Kiwamu will post some plots with the MICH OL TF; here are some numbers for the REFL 45 phase:

Without the arms: 144 dg

1 kHz --- 900 Hz CARM offset: 172 dg

800 Hz  --- 700 Hz CARM offset: 180 dg

We were happy and ready to do the transition to 3f, but another seismic event like the previous one made the lock of the Y arm more difficult. 

We are still debating if we should go home or not...

[Jamie, Kiwamu, Lisa]

The ETM SUS are getting kicked to the point of watchdog trips when the we lose the ALS DARM lock.  The DOWN state of the ALS_DIFF guardian was shutting off the INPUT to the LSC-DARM filter bank, but not the OUTPUT, so we were suspecting that leftover filter stuff was being driven out to the suspensions.  There are also no LSC triggers associated with the ALS error signals that could shut off the DARM output after lock loss.

I modified the ALS_DIFF DOWN state to turn off the DARM output as well, in the hopes that that would reduce the problem.  We thought that that did help, but then we just got another lock loss that did trip the ETMY SUS and ISI ST2 watchdogs, so it didn't elliminate the problem entirely.

I wonder if we'll need to add some LSC triggering based on the ALS inputs, for when we're using ALS signals to feed back to the SUS.

While I was at it, I did a bunch of code cleanup in the ALS_DIFF module.  Mostly just to keep things consistent with the guardian style guide (unpublished).  I also committed the ALS_DIFF.py module to the USERAPPS svn, and added it to the GUARD_OVERVIEW medm screen.
 

Kiwamu, Jamie, Lisa

Today we had the illusion that we could start locking before dinner time, but that didn't happen.

While both the X and Y arms were locked on green, something happened in the corner station (visible in the PEM CS SEIS 30-100 mHz channels, especially Z) which affected only the Y arm, while the X arm remained happily locked.