Evan, Keita, Kiwamu, Alexa

It had appeared that the temperature in the LVEA had stablized (alog 15054) so we went about realigning in the IFO. Here is the original alignement we started with:

Here are the initial steps we took:

1. Align/lock X and Y arm on green. Note: this required a big adjustment since the temperature had also drifted in the end station.
2. Adjust PR3 to get COMM beatnote back to nominal of about 0dBm; I adjusted PR3 by +2.5urad in pitch, and +0.3urad in yaw
3. Lock the IR to the X arm; this required an adjustment of PR2 in pitch by -34urad.
4. Run the wfs feedback to IM4, PR2 to get full build of IR in the x-arm

At this point, we noticed that the WFS had brought IM4 to a bad alignment. Keita has measured the PR2 baffle clearance (alog 15063); and IM4 was not within range in YAW. So we basically started from scratch, and did the following:

1. X,Y arm locked on green
2.  X arm locked on IR
3. Run wfs to keep IR build up at a maximum and adjust PR3 until IM4 was at a good position. I had to adjust PR3 by +2.5 urad in pitch, and -76.1 urad in yaw.
4. Adjust HAM 3 pico's to get the green beams on ISCT1; i.e. to restore our usual values for ALS-Y, ALS-X_TR_A_LF_OUT  ~ 1 cnt each
5. Adjust the DIFF and COMM beatnote on ISCT1. Evan had to move the BS in the DIFF path because the X-arm was almost completely off the BS (he will post more about this).

Now we have the following:

COMM beatnote: 6dBm, DIFF beanote: -1.6dBm. When I get a chance again I will take a snap shot of the ALS camera images, but for reference these image is a bit clipped for both beams; however the transmission is good and the beatnotes are good so it's just the image.

Apparently, the end station temperatures are still drifting. This will affect the DIFF beatnote. Unfortunatly if EX drifts a lot we will need to re-do this input alignment again ...

08:22 Ken to end X to move AC receptacles (WP 4945)
08:45 Jeff B. and Andres to end stations to pack up tooling
08:52 Karen to end Y to clean
09:00 Chris done cleaning in LVEA
09:01 Aaron and Filiberto to end Y to pull PEM cables
12:05 Karen done
12:06 Jeff and Andres done
12:13 Aaron and Filiberto done
13:07 Bubba to inspect end station mechanical rooms
15:01 Cyrus to mid X to test phone
15:03 Suresh to adjust optical lever by HAM3
16:02 Suresh done

Alexa, Nic, Jim, Dave

Alexa reported strange LSC-PD_DOF_MTRX input ramped mux matrix behavior last weekend. Symptoms were: new element values were taken immediately without loading, ramping continued indefinitely. The current theory is that a rogue script is setting H1:LSC-PD_DOF_MTRX_LOAD_MATRIX to 1 frequently. On monday this channel was added to conlog, and conlog reported that during monday afternoon and early evening this EPICS channel was being set to 1 several times a second. We also discovered that the DAQ trends were not showing this high frequency activity, this underreporting is under investigation (only seen in the LOAD channel, all other matrix channels trend correctly).

At 11/10 20:19PST monday evening the rogue loader stopped running and has not restarted since. Initial scans of guardian and home account directories have not found any script which would be loading the matrix frequently. Guardian logs its PV settings and these are seen at very low rates (max 100 per day). We may have to wait for the problem to reappear in order to track it down further. Investigation is continuing.

As noted over the last few days, the temperature at LHO has dropped significantly over the last few days and the HVAC temp control of Ey and the LVEA have wandered more than normal.  For the record, attached is an 8 day trend showing the temperature drop at End-Y versus the ETMy main and reaction chain vertical, pitch, and yaw positions.

New IM4 nominal bias sliders: [13350, -5056].

Good range for IM4 bias after the initial alignment procedure is [13350 +- 2400, -5056 +- 330] assuming that the MC is behaving well.

The "good range" gives you +-2 mm displacement on the PR2 baffle, which is a non issue for clipping, or +-60urad in IM4 rotation.

IM4 slider calibration was remeasured, it's: 0.025 rad/bogorad for PIT, 0.182 rad/bogorad for YAW.

The slider change from yesterday, i.e. [3364.4, -118] slider counts (micro bogorad), corresponds to [88.3, -21.5] urad physical rotation.

What was done:

After the LVEA temperature settled, IM4 was scanned while the PR2 baffle and the SRM baffle was monitored. Before I started IM4 [P,Y] was [9985.6, -4938].

For IM4 YAW, I was able to see when the beam barely touched the PR2 baffle edge, and when the straight shot beam on SRM baffle disapperaed. I made the average to determine when the beam is 50% blocked.

For PIT the driver railed before I was able to completely block anything, I only recorded when the beam barely touches the PR2 baffle edge.

Since baffle hole appears to be a 65.4mm diameter circle, and since the beam is supposed to be 26mm from the right edge, the new position is

P = (52000-25300+-1400)/2 = 13350+-700.

Y =26/65.4*(1300+-70) + 39.4/65.4 * (-9250+-140) = -5056+-90.

Slider calibration is the angle over the baffle diameter 65.4mm/17m divided by two divided by the slider difference, i.e.

calibration for P = 65.4e-3m/17m/2/(52000E-6+25300E-6+-1400E-6 bogorad) = 0.0249(1+-0.02) rad/bogorad

for Y = 65.4e-3/17/2/(1300E-6+9250E-6+-160E-6) = 0.182(1+-0.015) rad/bogorad

JeffK says may be a leftover from unexplained ISI trips.  I'll study.

Here are TFs from the Ground STSs to the ISIs GS13 in low gain.  I'll switch to high gain and compare when that transition won't potentially disturb the commissioners.

In low gain, there is good coherence bewteen 2 and ~10 hz.  Cross couple channels, shown for HAM2, are all pretty small.

See plot...I don't know what this is.

So this ISI sat tripped for some 20 minutes until I was scanning the SEIs.  I will implement an alarm system so these do not languish.

It tripped at Nov 14 2014 03:48:32 UTC, which is 19:48:32 local time yesterday.

I noticed while walking by that air currents (from my passing) caused the curtains to swing free and then thump on the box.  This doesn't seem good.  The curtains could likely be tied back, easy.  Or maybe the cleanroom should be moved, a bit harder.

Seems like the temperature was already good-ish as of 18:00 or so yesterday.

Doug will rezero SR3 optical lever around 10am
The beam balance is misbehaving, Krishna will be here Tuesday to investigate
PEM cabling at end Y
Ken moving AC outlets at end X
Jeff and Andres packing and removing tooling at end X and end Y

Looks like an unwarranted glitch on the actuator.  The CPS aren't moving before the trip.  The GS13 respond quickly (hard to tell if this is cause or effect) but again there is no preamble.

J. Kissel, A. Staley, K. Izumi, K. Kawabe

Continuing investigations of why ETMY behaves poorly when attempting ALS DIFF (see LHO aLOG 15037) -- I've looked at two more things:
(1) Pitch-only optical lever Damping: This had been turned on only *after* it had been decided that ETMY was "fragile," i.e. any impulses would shake the SUS quite a bit -- but I checked it anyways. First attachment is comparing spectra with the PUM (L2) stage actuated, optical lever Pitch damping loop ON vs. OFF. It's damping pitch, as expected, and not injecting anything terrible. This of course is assessing the stationary noise, and we're worried about non-stationary problems ... but ruling things OUT with quantitative data, I feel, is just as important along the investigatory route.

(2) DRIVEALIGN Matrices: I attach comparisons between everything in the ETMs UIM (L1) DRIVEALIGN matrices (Only the P2P, Y2Y, and L2P have anything in them, so those are what's compared in the attachment). I believe the original design intent for P2P and Y2Y filters was to have global WFS transfer function be similar to the test-mass transfer functions -- hence the high-Q, plant inversion-y type stuff. They are slightly different between the two test masses, but, in-fact, they don't matter matter at all because we don't feed any angular signals to the UIM stage. 

However, I've found that the ETMY UIM L2P frequency-dependent decoupling filter in the UIM bank is significantly different than ETMX's -- and the filter has a much larger step response. I compare three different sets of filters on pgs 1 and 2:
ETMX -- FM1 & FM2, "L2P" & "L2P2" 
ETMY, Current -- FM1, FM2, & FM4 "L2P", "L2P2", and "BetterRolloff"
ETM, Legacy -- FM6 & FM7,  "L2Plegacy" & "L2P2legacy" 
It looks like the initial story here is laid out in LHO aLOG 11832, but there're several more aLOGs referencing UIM / L1 L2P Filters, and how they've been bad, they've been good, they've been turned off, they've been turned on...

The foton calculation of the step response disagrees with the measured step response LHO aLOG 14832 -- but recall that the filter step response is not the only thing measured in that 14832 measurement -- it's measuring both the filter AND mechanical step response. We now have local damping filters from LLO which has reduced the mechanical impulse response time by a factor of a few. This, coupled with a smaller impulse response filter should help, but we'll remeasure once a new filter is designed.

I'll move on to chasing this down -- re-measure the step response, and also remeasure the plant upon which these filters were designed.

Of course, an immediate, band-aid fix could be just to copy ETMX's L2P filter over to ETMY, but while we wait for the temperature in the VEAs to settle down, I've been given the green light to measure some TFs.