SEI - Jim is installing new osolation filters on BS.  McCarthy may install a new power supply for te EX HEPI pump controller.

SUS - Charge measuring in EY

CDS - RF cab;le pulling between TCS racks. Discuss plugging in rotation stage

Matt is working on TCS X and Y and clearing errors on TCS-X AOM

Bubba found a bad bearing on one of the axial fans. He will be repairing.

3IFO- Bubba installing dewpoint sensors on containers. Jodi ad Gary tagging ISC and Baffle stuff.

Corey working in Squeezer bay

HFD - in LSB doing tests.

08:08 IFO fully locked @ ~ 18Mpc  (according to SensMon).

Evan, Sheila, Dan, Kiwamu, Lisa 

SUMMARY 

The wind dropped below 20 mph in the evening, and we started locking. After some roll, bounce and violin damping, we made it to DC readout @ 8W. We successfully transitioned DARM to ETMY with low noise ESD and got some MICH feed-forward cancellation going. We improved the noise between 30-200 Hz, and reached  28 Mpc  (according to SensMon). 

The noise was more stationary than  previously observed . 

However,  the OMC is still shaking , and it is not good. Dan has a resonant gain for DARM ready to be tested to reduce the noise around 3 Hz, but we didn't manage to get that done tonight. 

We leave the interferometer locked at 28 Mpc starting at March 24, 2015 9:17 UTC . 


DARM control on ETMY with low noise ESD  

We did the transition from ETMX to ETMY L2 for DARM, but the interferometer was very glitchy, and we decided to abandon L2 control and try the new  Den's strategy  to do the feed-forward to ITM(Y) L2. 
Evan got about a factor of 10 subtraction (FM9 has BS plant inversion in LSC-MICHFF filter bank, gain +0.048). 

ASC cut-off filters 

Since none of the ASC loops had cut-offs, we decided to add  some . They are now engaged by the Guardian. A more fine tuning will happen at some point. 

Started switching coil driver to low noise  

We started switching the coil driver to  low noise . Evan will post a table later with the successful switches we did after acquiring the DRMI lock. We need to do more work on this, some failed.

Lisa, Dan, Sheila, Evan, Kiwamu

We checked the evolution of the flickers in OMC TRANS over time.  It appears that the features between 1-5Hz have always been there, but the amplitude has grown by a factor of ~3-6 in the past two weeks.

In the attached plot, the ampltiude of the 3Hz peak on Mar 6 was about 0.004 / rt[Hz], and today it is 0.02 / rt[Hz].

We've added rolloffs to the ASC loops, turned on the 'resg1' filter in the ETMY_M0_DAMP_L filter bank (this adds a RG at 1Hz and an overall gain of +6dB), and looked accusingly at the OMC TRANS camera image.  No change so far.  Next idea is to try a boost in the DARM loop gain at low frequency.

Lisa, Evan, Sheila, Keita, Jim W, Kiwamu,

Today we had an issue in which the Y end PDH loop kept unlocking due to a high longitudinal motion (more than 12 um peak-to-peak at 50 mHz). The wind was high at 20 mph on average with 40 mph at highest most of the time today starting from 9 am local. In this report I attempt to summarize the issue associated with today's windy condition.

(Y arm motion was too high)

When we started fully locking the interferometer, we noticed that the ALS loops frequently dropped their locks in the middle of the locking sequence. It turned out that the Y arm motion was so high the end VCO saturated in every several minutes. The X PDH also had a similar amplitude but it was slightly smaller than that of the Y arm by ~ 20% which barely allowed the X arm to stay locked. The attached is a 5 minutes trend of relevant channels under a condition that:

• without ALS diff loop.
• without ALS comm loop.
• with local tidal feedback loops on X and Y arms with UGF of about 0.03 Hz for both loops.
• ISI ETMX stage 1 is in 90 mHz blend configuration without the BRS correction
• ISI ETMY stage 1 is in 90 mHz blend configuration.

As shown in the plots, the Y arm PDH control signal (ALS-Y_REFL_CTRL_OUT_DQ) went up and down at a frequency of 50 mHz. This channel is calibrated into the Y arm displacement in um. When it went below -7 um or above 7 um it unlocks essentially because the end VCO rails. The X arm showed a similar amplitude, but amplitude was not as big as that of the Y arm. The X arm dropped the lock less frequently than the Y arm.

(Some attempt with a high band width tidal)

We then started increasing the bandwidth of the local tidal feedback which picks up signals from the end PDH control and offload it to the L1 stage of ETMY. The idea is that we wanted to physically quiet down the ETMY motion so that the VCO can stay within the range. We increased the gain of both X and Y local tidal loops by a factor of 3. So their UGFs are now 0.1 Hz.  At the end the attempts, the wind incidentally came back down to 10-30 mph so we can not really say if this scheme helped.

I added a new Guardian node to the overview screen today (screenshot attached). SYS_DIAG will run different tests to check for particular conditions. If a test finds a problem it will bring up a notification. Just like other Guardian nodes, opening the main screen will allow you to click on all notifications and see the entire list, otherwise it will cycle through them in the space provided on the mini.

I will still be tweeking little things here or there, but it is definitely usable/useful now.

The tests that it currently runs are :

• ALS_SHG_SERVO: Checks to see if the ASL SHG Temp Control Servo is ON
• BRS_DAMP: Check if the BRS Damping turntable is on and working
• BRS_DEAD: Checks if the BRS is software dead or needs to be rebooted
• SEI_STATE: Checks is the SEI systems are in their nominal configurations
• TCS_LASER: Checks the TCS laser output (only TCSX for the moment)
• BLRMS_MATRIX: Checks if the BLRMS matrices are mostly green
• COIL_DRIVER: Checks that coil drivers have not gone down
• SUS_OUT_OF_RANGE: Like the Drift Monitor, if a suspension stays too far it will notify
• PEM_CHANGE: For now it is only looking at major earthquakes (VEA temps, high winds in the future)
• MC_WFS: Checks the MC WFS are engaged
• OL_SUMS: Check OpLev sums are low when suspensions are aligned
• SW_WD: If a software WatchDog is tripped....we will know
• Bounce/Roll/Violin_Modes: Checks if the quad modes have rung up (thresholds need some works still)
• PSL_Noise_Eater: Check that the Noise Eater is engaged
• DAC_CTRL_SIGNALS: Checks that the SUS and SEI are sending out control signals (not running yet)

When you select the requested state to INIT the log will list out the tests that it is currently running.

If there are other tests that you would like to see on here please let me know!

Scott L. Ed P. Chris S.

61 meters cleaned towards single door between X-1-6 and X-1-7.
Continuous monitoring of beam tube pressures by control room operator during cleaning operations.

Bubba John W.

All of the axial fans are lubricated.
Corner station SF 4 has at least 1 bearing that needs to be replaced and is currently off line awaiting parts. We will monitor the LVEA temperatures very closely but this should not have any adverse affect on the temperatures. 
End X SF 2 also has a bearing that is suspect. This fan is off also. 

07:00 Cris and Karen into the LVEA

08:25 RMS wathcdogs tripped on ETMs. ETMY reset from medm reset. ETMX still showing a trip on L2 UL.

08:53 RMS trip on L2 ETMX cleared by power cycle

09:35 ISS diff power was up to 10% +. I adjusted the refsignal to (-)2.07 for a net diffracte power of ~7%.

10:07 R McCarthy back from installin ESD filter at EY

10:16 Bubba to start greasing fans at mid stations. (MidX first)

10:45 Jim switched end stations from 45MHz ISI filter blendsto 90MHz filter blends due to the SSW winds exceeding 35-40 mph.

11:21 Jodi to MidY

11:34 Bubba movning to mid Y 

12:02 Very windy day today. Sustained winds at ~26mph with gusts exceeding 40 at times

12:15 D Barker and J Batch to EX (non VEA)

12:55 Bubba and John to EX to grease fans

13:27 D Barker and J Batch to EY (non VEA) to address TCT (timing) problem.

13:46 Bubba and John to EY to grease fans

14:30 Calum and Kate on site

14:35 Bubba and John back from Ends. 

16:00 Bubba done with fans.

This message tests the automagic emailling of the detchar@ligo.org list when the 'DetChar' task is used on a post.

Following up on Kiwamu's report, here is the summary page for the coherences during the low noise lock:

https://ldas-jobs.ligo.caltech.edu/~gabriele.vajente/bruco_1110961816/

As usual, here is my digest.

In brief: we need MICH/SRCL subtraction, check SRC angular controls, they might be injecting noise, better tune the IMC longitudinal offset if possible

More details:

• At low frequency, below 5 Hz, the most prominent coherence with with SUS-ETMY_M0_DAMP_L_IN1. However, I'm not sure about the origin of this signal, so it might well be that it's just a DARM control signal fed to the top stage.
• Below about 100 Hz and especially below 30 Hz there is a significant coherence with SRC angular signals, in particular: SUS-SR2_M3_LOCK_Y_IN1 and SUS-SRM_M3_LOCK_Y_IN1. My guess is that the SR2 and SRM control signals are very similar, after the implementation of the driving diagonalization 
• MICH is likely the dominant source of noise in the 20-100 Hz region. SRCL is showing large coherence up to 200-300 Hz.
• We still see coherence of SRCL and PRCL signals (and REFL/POP signals) at high frequency, up to kHzs. This is likely due to the IMC longitudinal offset. It seems to me that the situation is slightly better now.
• Coherence is high with IMC angular signals at the 200-400 Hz peaks
• At about 450-500 Hz there is a lot of coherence with ITMX_L2 signals, which I guess is due to the violin mode damping. It might be worth checking if this is re-injecting any noise
• Coherence with intensity noise is not very high, but neither very low. In particular there seems to be a line at 1080 Hz.

P.S. Why are you sending DARM signal into the CARM filter bank?

Commissioners were complaining of excess arm motion, so I've changed the blends on the beamline directions on St1, from the nominal 45mhz blends to 90mhz. To review for those not in the seismic know, this is done by opening the St1 Blend screen from the BSC ISI overview and clicking on the 90mhz blend in the appropriate direction (i.e. X for ETMX, Y for ETMY). Attached screens show overview with circled blend screen, St1 Blend overview, close up the blend X bank. It's not perfectly clear that we need to be using the 45mhz blend or if the 90mhz blend is good enough, but I've been talking to some of the commissioner about maybe doing an assessment when it's convenient.

TJ asked me about the BRS this morning, as it was tripping an alarm he had set. When I opened the overview, the numbers were rather large and swinging rapidly (over a minute it was going from -40000 cts to +40000 cts, the transition was a couple seconds. The attached dataviewer trend shows it has bee doing this since the 21st, starting about 15:00 UTC. No clue what happened.