J. Kissel, J. Warner

Excited to use the buried STS (see LHO aLOG 25574), Jim had switched over to using the recently-moved-to-20 [m]-from-the-building STS for sensor correction (coupled with some other new configuration changes he's trying out; see LHO aLOG 25623). He was getting poor results when comparing internal vs external sensor correction use, so I've compared the times yesterday when we had great coherence at 10 [m] and 0-5 mph winds against today, when the STS is at 20 [m] away and there are consistent 25-30 mph winds.

The message: both the internal and external ASDs, in X, Y, and Z, are comparable in amplitude and yet incoherent at this location and these 25-30 mph wind speeds. That means the buried STS is not so promising for sensor correction use at this level of wind.

One can compare this to results originally presented by Robert at the 40 [m] location in ~15 mph winds; see LHO aLOG 19210. 

You'll notice that in both of these data sets, the contrast in amplitude difference between windy and not windy is "better" in the X DOF (perpendicular to the arm) than in the Y DOF (parallel with the arm; what we're trying to improve). 

We shall continue to take a smattering of data points to gather statistics at all wind speeds in this location.

For the impatient and saddened -- recall that we have or will employ three different methods to attack wind at EY:
(1) This buried, external STS [in the testing phase now]
(2) A new BRS [scheduled for delivery in mid-March]
(3) A wind screen system [working on getting funding] 
We're trying all three just in case one actually works. Let's hope one does!

In December, I suggested a design for a new sensor correction filter for LHO. For most of the last month the end station ISI's have been running running this for a while, but I haven't had a good opportunity to do any comparisons of the interferometers performance. For now, I'll summarize the changes to the end station's configuration. During O1, we used 90 or 45mhz blends on St1 X&Y (depending on microseism) and the .46hz sensor correction (stolen from LLO) from the ground STS to St1 CPSs. For a good portion of the last month, I've been running the end station ISIs with my useism sensor correction to St1 and I moved the .46hz sensor correction to St2. I think that this configuration has allowed us to use the 90mhz blends with higher microseism, but I still haven't come up with a measurement to show that.

My first two attached plots show the difference in X between these two configurations. The first plot is the St1 perfromance (T240's blue and red) and  ground STS (pink and light blue). Dashed is with the "01" configuration, solid is with the current configuration. As expected the current performance loses some around .5hz, but  gains a factor of 2-ish suppressio of the microseism. The second plot shows the St2 GS13s and ground. Green is the current configuration, brown is the O1 configuration. The current configuration (useism senscor on st1, and st1-2 senscor) does better most places except for some gain peaking around 50-60mhz. It would be useful to compare the current configuration to performance with the 45mhz blends, which suppress the microseism better, but have more gain peaking below 100mhz and are adversely affected by wind.

The last plot shows the suppression (the transfer function from the ground STS to the St2 GS13s) of the 01(dashed brown)  and current (solid blue) configuration. The story is the same, the current configuration does a better job between .1 and ~1 hz, a bit worse below .1 hz.

I have more configuration stuff to log, but I'm out of time for the moment. But HAM1 has inertial isolation, and I've added St1-2 FF in Z to the BSCs.

Heliax cable for the 71MHz CPS Sync was pulled in this morning. Cable goes from the CER to SUS rack H1:SUS-R3 (next to HAM4). Waiting on N bulkhead connectors for the 2U N patch panel.

The new EOM/AOM driver field cables (2 DB9 and 2 DB25) were pulled from the CER ISC racks to the PSL racks in the LVEA. Cables still need to be routed inside the PSL enclosure.

For now, we left the old temporary field cables connected. These will need to be pulled out of the cable trays later on.

Here is the summary of the working SVN directories we have at LHO and the number of locally modified files in them pending commits to the repostitory.

* all working directories are under /ligo/svncommon/ except for user apps which is in /opt/rtcds/userapps

[Cao, Ellie, Dave O, Aidan, Nutsinee, Kiwamu]

We scanned SR3 last night for 7:50:00 (LHO alog 25600). We use Aidan's MATLAB script from LLO alog 9368 to identify beam spots on the HWSY.  The three plots below are

1)HWSY_refl_map_early.jpeg  showing the averaged intensity early in the scan

2) HWSY_refl_map_lin.jpeg showing the averaged intensity after full scan with linear intensity colormap

3) HWSY_refl_map_log.jpeg showing the avegaed intensity after full scan with log intensity color map

The spots look very different from that recorded at LLO as expected due to the wrong optics install in vacuum. The images of full scan show four beam spots. We first checked the source of two upper bright spots by misaligning the ITMY. There were no change in the bright beam spot observed on the HWSY. Therefore, these must have come from the 2 surfaces of the compensation plate (CP). The beam correponding to the left bright spot is currently centered on the camera.

We then checked the bright spot immediately underneath the current position of pitch and yaw (which is at the center of the plot). By misaligning the ITMY, we saw the beam spot on the camera move. By further adjusting the pitch and yaw of ITMY, we could see the beam spot disappear. Therefore, this beam must have come from one of the surface of the ITMY.  The high intensity shown on SR3 scanning plot gives a strong indication that this beam comes from the HR surface of ITMY.

We will center this beam onto HWS this afternoon by walking the SR3 and periscope mirrors this afternoon. We are also planning to to run a definitive test tonight to confirm the source of this beam spot and see how far off we are from centering the beam by turning  the ring heater on with the HWS running.

I've added all the filter gains to the MEDM screen as well so they can be clearly read (in-line after the corresponding button for each filter screen). These represent the steady-state diopters per Watt value for each actuator.

Richard put in the fix for TMSX satellite box and the oscillations are gone.

The ROC and ITM substrate defocus estimator seems to be working correctly. The following two plots show the last 17 hours of (a) the XARM transmission and (b) the ROC of the four test masses as well as the single pass thermal lenses in the substrates of the two ITMs.

The estimator was engaged about 17 hours ago - which is when it first saw a signal from the ETM RHs and the ITMX CO2 laser. Hence, these ETM ROC is decreasing over time as the RH effect engages (also showing the classic RH overshoot after approximately 3 hours). Also the ITMX substrate lens starts from a static lens of around -1.2E-5 diopters and increases over around 4 hours to settle at it's nominal value.

Additionally, the IFO was being locked and unlocked. The six estimators show this transient behaviour as (a) ROC increasing during a lock and (b) ITM substrate defocus increasing during lock.

(all times in UTC)

Hand off from TJ with him aligning the SRC, but it looked off.  Sheila & I found that the SR3 was off in yaw (thru oplev trend & AS_C PD), so this was steered back, and then went through an SRC Alignment.  

Den:  tested out some MICH & BS filters to test DRMI acquisition

Then spent most of the evening trying to get H1 to NLN, but there are some ASC issues floating around.  

One cool thing is seeing DRMI locking super fast.  I noted some of the acquisition times here:

• 1:05:54 - 1:07:48---> under 2min
• 1:29:31 - 1:31:20--->1min49sec
• 2:56:48 - 2:59:48--->3min
• 3:17:45 - 3:18:11-->26 sec
• 3:34:08 - 3:34:38
• 3:38:25 - 3:39:38

o 0:32-1:05 Dave/Jim heading to EY to check seismometer

o 3:52 acknoweldged a GRB but we were locking.

Leaving Operating Mode in Locking as I leave H1 to Den for the evening.

I'm not sure why, but BS gets a large kick in Pit and Yaw just before it goes into the coil drivers state.  We've seen this 3 times in a row now, although these were the first times since ~lunch that the IFO was locked past DC readout.  So, it's perhaps related to our alignment / locking troubles, which are perhaps due to this LVEA temperature change that happened on Tuesday. 

The transient is visible in the LOCK_P and LOCK_Y channels for BS M3, but not in LOCK_L.  It is also visible in the WFS signals.

Had a couple of random HAM5 ISI/SRM_M1 watchdog trips.  For both watchdog trips, it looks like HAM5ISI is first.  The trips happened during two different states of working on H1.

1)  At end of TJs shift when there was a lockloss from DRMI.  The GS13s & Actuators both hit their limits.  NOTE:  on this one, SR3 was quite a bit off in yaw!

2)  While aligning H1, HAM5 tripped in a similar way.  NOTE:  No issue with SR3 here!

For both cases, all the M1 OSEM RMS values start increasing (not enough to trip the WD), but it's interesting to see them all ramp up.

For the first case, Sheila made a change to Guardian to make sure we look at when DRMI drops out of lock.  Still not really sure what caused case #2.

Received an FMCS Air Handler HIGH RED alarm.  This evening.  I've acknowledged it, and it will probably stay in the RED state until addressed (if this is a new running state, we should update the alarm handler).

This might be correlated with John turning off heaters on Tuesday, but not sure.

Will send an email to John/Bubba.

I reduced the gain of the OMC length locking loop by a factor of 3, the UGF has gone from 10 Hz to 3 Hz, and added a 30 Hz low pass.  The new open loop is attached, as well as a spectrum of the drive signal before and after this change.  There are low passes in the PZT driver that mean this is not as dramatic a change in the OMC length RMS as it seems.  

Noise projections coming soon.  

Sheila, Den

We have tuned DRMI servos to reduce the acquisition time. First of all, we noticed that MICH servo saturates the BS actuator during the flash. In order to solve this issue we have copied control filters from LLO. Attached plot shows comparison of LLO and old LHO MICH servos. Next we have changed locking threshold for SRCL and changed ramping time for PRCL and SRCL boosts.

New changes are in the guardian's "NEW_DRMI_SETTINGS" state. We tested these filters (~10 times) and concluded that there is an improvement in lock acquisition time. Average DRMI wait time is 1 minute.

[Cao, Ellie, Dave O, Aidan]

To whoever will be around in the control room last after commisioning, here are the steps for SR3 scanning to align Y arm HWS:

1- Turn off SR3 Cage Servo , Make sure that all mirrors are in ALIGNED state.

2- Run arbitrary waveform generator for H1:  SUS-SR3_M1_OPTICALIGN_P_EXC.

             Frequency has been set to 41.7 mHz

            Amplitude has been set to 750 urad

3- Run arbitrary waveform generator for H1:  SUS-SR3_M1_OPTICALIGN_Y_EXC immediately after step 2

            Frequency has been set to 10.3 mHz

            Amplitude has been set to 1550 urad

Let it run over night

All relevant windows have been left open on computer operator1 10.20.0.81

I filled the PSL diode chiller with 350ml of water.  Attached is a 30 day plot showing where the diode chilller was filled on Feb 4th, and then the alarm level increasing starting around Feb 13th.

I have increased the LLCV valve setting to 18% (from 15%) to try and compensate for changing conditions.

Factors that are changing are:

The supply pressure is falling as the liquid level in the storage dewar falls.

Heat leak to the liquid transfer line is increasing with outdoor temperature. This results in more vapor in the line and less liquid to the pump.

Radiation from the beam tube as the beam tube warms.

The attached plot shows 100 days of the control valve setting. The flat line at 15% is due to the failure of the differential pressure sensing- we have had to resort to manual setting of this valve.