Kiwamu, Alexa, Sheila

Tonight we have locked DRMI on 3F +the arms on ALS many times.  We were able to sweep COMM from one side of the resonance to the other, and DRMI stayed locked. 

• We added PRCL subtraction to the SRCL error signals, for 1F we have a -8 in the input matrix, for 3F we have 0.4  For the 1F, this helps DRMI acquire lock faster.
• We have tried slowly decreasing the COMM offset from 500 Hz (in IR).  We have been losing lock between 150-90 Hz offsets, we don't know why.  We werwe in the process of checking for coherence with the arm signals and checking loop gains as we slowly reduced the offset when a 7.2 earthquake hit off Nicaragua. 
• The good news is we have locked DRMI +arms several times and it is stable for many minutes, up to 20.

Times:  DRMI +arms off resonance , on 1F 00:23:54 UTC october 14th 2014.  transitioned to 3F, 00:30:25 UTC

There was one time that we had difficulty locking DIFF, we disabled the LSC DARM offset and this might have helped.

H1:FEC-98_IPC_LSC_ETMX_L_SUSETMX_ER

H1:FEC-98_IPC_LSC_ETMY_L_SUSETMY_ER

Seems like these have been non-zero for like forever (why?), but the error counts jumped up on Sep/05/2014 and never came back down.

A whitening chassis at EX seemed to have died on the last Tuesday. This should be fixed.

• SN: S1101631
• location: U5 at EX field rack

All four segments of both in-vac IR QPDs (ASC-X_TR_A and _B) had been reading some bogus values since approximately 7 pm of 7th of October in PDT. Dave and I looked at the reboot logs and confirmed that no software activities were performed since 3-ish pm in this particular day. We suspected some analog issue and therefore I went down to EX to check out the circuits. The AA chassis seemed to be working fine because the raw ADC counts had gone when I disconnected the signal cables. Tracking the signal lines further, I found a whitening chassis whose +15 V LEDs were all off. I power-cycled the chassis and this resulted in change in the level of the bogus signals, but this did not still give me realistic signals. The +15 V indicators are still off. We need to replace this unit.

8:10 ISS Diffracted power adjusted to 9.5 % - Operator
9:26 Hanford Fire Department on site to work on RAFAR boxes at EndX/Y
9:27 Heading to EndY to work on Green WFS – Keita
9:47 SRM AA Chassis work in LVEA – Richard/Vern
9:56 3IFO Quad work in LVEA (West Bay) – Betsy/Travis
11:53 Returned from LVEA – Richard/Vern
12:40 Back from End Y – Keita
13:40 Heading back to work in the LVEA – Betsy/Travis
13:49 Going to the LVEA to check on a vacuum rack - Richard

This morning while the interferometer was tied up with other work,  I took a quick look at the length to angle coupling of ETMX. 

The bottom lines:

• M0 seems OK
• the impulse response of L1 L2P seems bad. 
• In the configuration used for ALS DIFF, the DC coupling seems OK

I had a look at the impulse response by applying a million counts offset in L3 INSINF and watching the oplev time series. The first plot shows the reponse of the three stages used in ALS DIFF (Mo, L1, and L3) with the filters set as they would be for DIFF, with the other stages turned off.  You can see that L1 causes a large response in pitch, while M0 seems to be fine. 

The next plot shows the response of the L1 stage alone. With the L2P decoupling off, we get less of a response in pitch, while turning off the L2Y filter doesn't make much of a difference. Based on this I have turned off the L2P on L1 for now.

The last plot shows the immpulse response of all the stages, with everything as nominal for ALS DIFF.   In the red trace, the L1 L2P filter is off, in the blue trace it is on.

As a follow up to the measurments I ran on ETMY last week, I ran a similar measurement on ITMX this morning. To recap, all of the isolation loops were engaged on the ISI, blends swith to Start, and I drove in low frequency in Z on first the ISI, then a second round on HEPI. In the attached plots, the dotted references are the first measurement, the solid lines are the second. Pretty much the same story as last week, with some weird tilt-looking coupling when we drive on the ISI that seems to disappear when I drove HEPI. I included the L4C's this time around. Curious that the L4C's don't seem to see the coupling as much as the T240 do, but more than the cps's do (which I didn't get this time around).

I tried to measure the Flex modes (T240 over-constrained modes), but their cartesian component matrix elements are all zeroed, so I didn't get any data. I'm unsure of what those values should be, and they aren't defined in Fabrice's Sensor Location document, T1000388.

With the microseism being elevated over the weekend--looked at the floor seismo wrt the HEPI L4Cs.  We'd really like to help with microseism noise but it is a tough problem.  However, something just doesn't seem right.

Looked at coherence between the floor sts2 and BS HEPI X Y Z Blend inputs.  Strong coherence with Z but X & Y pretty poor.  Looking at the locally oriented sensors and whoa, strong coherence with the diagonally oriented HEPI L4Cs split between the X & Y...  See attached.

The upper left panel has the coherence with the cartesian basis blend inputs.  Strong in Z but oor in X & Y.  The lower left panel  has the local basis horizontals with the X ground signal: Strong in H1 and H3, the sensors oriented NE to SW (building crane basis.)  The H2 & H4 sensors, oriented Nw to SE show little to no coherence.  The upper right panel looks at the horizontal local sensors wrt the Y ground motion and the result is the opposite: strong signal with the H2 & H4 L4C but little to none in the H1 & H3 signals.  The lower right shows the strong coherence in all the Z local L4C signals with the Z signal from the floor seismometer.

Since the Z signal has good coherence, I don't think there is any problem with the model path, maybe?

Since the Local to Cartesian transformation has equal magnitudes (the local sensors are oriented at 45 degrees to the LIGO referencef frame, I don't believe the matrices are to blame. These values are correct based on T1000388.

This leads me to conclude the the ground STS2 must be oriented incorrecty or its internal U V W transformation to X Y Z is messed up.  This will certainly cause issues with sensor correction etc.

Laser Status: 
SysStat: Warning “VP program online” is red
Output power is 33.5 W (should be around 30 W)
FRONTEND WATCH is active
HPO WATCH is red

PMC:
It has been locked 5 days, 22 hr , and 54 minutes (should be days/weeks)
Reflected power is 2.0 Watts and PowerSum = 25.7 Watts.
(Reflected Power should be <= 10% of PowerSum)

FSS:
It has been locked for 1 d, 7 h, and 9 min (should be days/weeks)
Threshold on transmitted photo-detector PD = 2.26 V (should be at least 0.9V)

ISS:
The diffracted power is around 9.5% (should be 8-10%) 
Last saturation event was 2 d, 19 h and 0 minutes ago (should be days/weeks


NOTE: The ISS Diffracted Power was out of its range (8-10%) this morning. It was fixed by adjusting the ISS Reference Signal value.

model restarts logged for Sun 12/Oct/2014
2014_10_12 08:44 h1fw0
2014_10_12 18:27 h1fw1
2014_10_12 21:41 h1fw0

all restarts are unexpected

K. Venkateswara

As described by Sheila in 14416, high wind speeds were recorded at LHO on Saturday. BRS shows corresponding high ground tilts during this period.

The first plot shows the ASD of the GND STS, BRS RY and Stage 1 T240 X. There is excellent coherence between the GND seismometer and BRS RY below 60 mHz and the tilt-subtraction looks quite good - you can clearly make out the primary microseismic peak at 55-60 mHz. Also shown is the BRS reference mirror (~sensor noise). After Fridays calibration corrections, the fudge factor I had to use was smaller (0.79) to get the subtraction right.

Stage 1 shows slighlty better coherence with GND_STS and BRS, but it is still limited by some other source of noise below 0.1 Hz.

The second file shows a band-limited BRS RY (5-500 mHz) and wind speeds as measured by PEM anemometers and converted to X and Y directions using the 'direction' data. I might have the axes converted incorrectly, but visually it shows good correlation with the BRS data.

Attendees: Bubba, Ed, Doug, Vern, Jodi, Keita, Jeff B, Jim, Hugh, Richard, Michael, Travis, John, Aaron, etc …

Today's Tasks: 


•	SRM and Lab work – Richard/Aaron, Ed, etc
•	Hugh working on Guardian (Reboots). 
•	3IFO Quad Upper Structure work continues in LVEA – Travis/Betsy
•	Beam tube cleaning will continue today – Bubba and crew 
•	TMS Optical Table assembly (3IFO) in staging building – Jeff B

The attached plot uses GMT on the horizontal axis.  The plot shows 1 - 3 Hz seismic noise last week.  Hanford contractors were hauling typical numbers of rubble loads on day shift and swing shift from Monday 10/6 through Thursday 10/9.  ERDF, the rubble pit, operated on Friday 10/10 but the number of trucks running to ERDF was low during the day on Friday and nearly absent on swing.  Commissioners can expect that the Monday-Thursday noise on this plot will continue through the fall.  Fridays will vary from week to week.  We're trying to learn the Friday haul estimates a day or two in advance.   

The big feature on the plot that shows during the weekend appears to be earthquake-related.

The ISS Diffracted Power was over 12% this morning. It is been adjusted to 9.5 % 

The ISS Diffracted Power was over 12% this morning. Is been adjusted to 9.5 % 

model restarts logged for Fri 10/Oct/2014
2014_10_10 00:22 h1fw1
2014_10_10 07:43 h1fw1

model restarts logged for Sat 11/Oct/2014
2014_10_11 05:33 h1fw1
2014_10_11 21:41 h1fw0

all restarts unexpected.

I'm leaving the interferometer with LSC feedback disabled, the the green lasers trying to lock to the arms.  We are currently having both high winds and high microseism, so anyone who is interested in looking at the motion of our optics or performance of ISIs when the ground motion is high could use this time, starting at 23:39 UTC October 11.

I've left the intent bit as undisturbed, could the first person to come in and commision or work in the LVEA toggle it to commisioning?

Alexa, Kiwamu,

We tried the DRMI tonight with the arm cavities held at a off resonance by ALSs. No exciting result yet.  

(Too high speed in DRMI)

We could lock the DRMI only twice and they did not last for more than a couple of minutes. According to the band-limited RMS plots in the control room, we are having a monontonically increasing micro-seismic tonight, starting 10 hours ago. (Presumably) due to the high seismic, the DRMI fringe tonight is much faster than usual.

(ESD-UIM crossover issue)

Also we experienced an issue in which the ESD-UIM had a bad cross-over. When we closed ALS DIFF, it stayed locked fine for the first 10 minutes or so. But we noticed that the DARM feedabck was slowly developing a 1-ish Hz oscillation which gradually started using up the ESD range. This eventaully caused saturation in either or both of the ESDs and we lost the lock. In order to avoid this issuem. we tried decreasing the ESD LOCK_L gain from 1 to 0.8 on both ETMX and ETMY. This reduced the amplitude of the oscillation and also the in-loop spectrum got back to how it had been. We are concluding that the cross-over between UIM and ESD changed from yesterday.

After adjusting the ESD gain, ALS DIFF reliably stayed locked for a long time, typically order of 20 minutes. Each lock ends usually due to misalignment in ETMX or ETMY.

(ETMX ESD check)

This is just an observation of ETMX ESD.

In the process of checking the ESDs and etc, we checked the reponse of the ESD in the pitch direction by shaking it at 4.1 Hz and looking at it with oplev. We noticed that shaking it in pitch mostly gave us yaw. Shaking yaw gave a good yaw motion though.  We checked ETMY and it was not the case.

(Sheila, Alexa)

Today we worked on the slow/tidal feedback to the ETMs. In doing so, we saw that the L2P for the M0 state was not very good at low frequency. Using the same method as was done for the BS (alog  14022), we found that the gain of ETMX L2P (with FM1, FM2 ON), should be changed from -1.0 to -4.0 at 0.01Hz. So far it appears that this is OK for high frequency. Meanwhile, we found that the gain of ETMY L2P (with FM1,FM2 ON) should be changed from -1 to 22 at 0.01Hz. We are not sure if this is okay at higher frequencies.

The slow/tidal feedback for both arms now works, and no longer causes a drift in the alignment. We made the following the changes to the feedback servo (this is all taken care of in the guardian already):

• ALS-X_ARM_GAIN: 210000 (old: -2100)
• ALS-Y_ARM_GAIN: -210000 (old: -2100)
• End station REFL PDH slow option is always disabled now; the slow feedback is engaged/disengaged by turning off/on ALS-X/Y_ARM input
• ALS-X/Y_ARM: we only have one boost on now

It appears that the DIFF PLL VCO is now in range, but maybe that's a coincidence with ground motion today....