model restarts logged for Tue 24/Mar/2015
2015_03_24 10:15 h1asc
2015_03_24 12:22 h1sushtts
2015_03_24 12:44 h1broadcast0
2015_03_24 12:44 h1dc0
2015_03_24 12:44 h1fw0
2015_03_24 12:44 h1fw1
2015_03_24 12:44 h1nds0
2015_03_24 12:44 h1nds1

• X1PLC1 10:13 3/24 2015
• X1PLC2 10:13 3/24 2015
• X1PLC3 10:13 3/24 2015
• Y1PLC1 11:3 3/24 2015
• Y1PLC2 11:0 3/24 2015
• Y1PLC3 11:0 3/24 2015

no unexpected restarts. Maintenance day: asc and sushtts cleanup, Beckhoff changes, associated DAQ restart.

Laura, Josh, Andy, Joe, Detchar

We took a look at the 28 Mpc lock on 24th March to see if there was any evidence of arches that we have seen previously at LLO (for example LLO alog 17090).

The first attachement shows a histogram of the rate of glitches (omicron triggers) binned by the value of IMC-F at the same time. The plot looks pretty Gaussian, except for a few bins specifically between IMC-F values of -37.5 to -41.7 and -45.8 and -50. Between these values we see evidence of arches in DARM. The second attachment is a pdf file showing the arches in DARM lining up with values of IMC-F in the second bin. Here are links to many spectograms confirming the arches in the IMC-F bins outlined (spectrograms for IMC-F bin -37.5 to -41.7 / spectrograms for IMC-F bin -45.8 to -50). Each spectrogram time corresponds to a glitch as seen by omicron.

LLO has dramatically reduced the effect of these arches, see LLO alog 17191.

Also the value IMC-F has when these arches appear in DARM seems to drift, i.e. there does not appear to be a specific value of IMC-F which produces the arches (this is evident in the second attachement). This is not what we have seen at LLO, does anyone know what could be causing this?

Kiwamu, Dan, Daniel, Elli

Today we locked SRMI using H1:LSC-REFLAIR_A_RF45_I_MON for SRCL and H1:LSC-ASAIR_A_RF45_Q_MON for MICH. This configuration is more stable than previous locks where we were locking MICH to ASAIR_A_LF and it was clearer where the locking point is.  We retook transfer function of AUX laser and carrier beatnote at OMC_REFL path against AUX laser offfset with and without beam clipping.  MICH offset was 20 counts of normalised H1:LSC-ASAIR_A_RF45_Q_MON so we were locked very close to the MICH dark fringe.  The raw data is available in /ligo/home/controls/elli.king/SRClengthdata.

I have unlocked SRMI and I am leaving the guardians in the down state.  We changed the whitening gain on REFL_A_RF45 for the measurement but I have set it back to zero and have reset the dark offsets H1:LSC-REFLAIR_A_RF45_I_OFFSET H1:LSC-REFLAIR_A_RF45_Q_OFFSET to tTuesday morning's values.

Kiwamu, Lisa, Sheila, Dan, Evan

Summary

A preliminary measurement shows that we are not quite limited by intensity noise between 50 Hz and 1 kHz, but we need to take another round of measurements in order to say anything conclusive.

This was taken before switching to the ETMY ESD and before feedforward subtraction of MICH.

This result is roughly consistent with Gabriele's conclusion that the intensity noise coupling above 100 Hz is a factor of a few below the total DARM noise.

Details

Kiwamu wired up the extra LSC DAC channel (LSC-EXTRA_AO_2) to drive the excitation point of the ISS second loop (PSL-ISS_TRANSFER2_INJ).

Then we drove a swept sine using this DAC channel and looked at the transfer function IMC-IM4_TRANS_SUM → LSC-DARM_IN1. The data aren't great, since it seems hard to get good coherence around 120 Hz and below 50 Hz. I've attached a calibrated version of the transfer function. IM4 trans is nominally calibrated into microwatts, and the conversion to DARM_IN1 from OMC-DCPD_SUM for this lock is 5.4×10⁻⁷ ct/mA (the DCPD_SUM channel is nominally calibrated into milliamps). The transfer function looks very feature-rich, and we would greatly benefit from a more careful measurement.

A good time to look at IM4 during this lock configuration is 2015-03-24 05:08:20 to 05:10:20 UTC. Using the ASD of the IM4 sum power during this time, one can use the above TF to propagate it forward to DCPD sum photocurrent. This can be propagated foward to DARM noise using the coefficient 4.6×10⁻¹³ m/mA. I've undone the DARM pole, but not the DARM loop (since our measurement is more or less above the loop UGF).

Lisa, Evan

Attached is a spectrum of the suppressed DARM error signal from last night. The RMS is about 3×10⁻¹³ m down to 0.1 Hz, and (as we've already seen) almost all of it comes from motion between 1 and 5 Hz. By looking at the recent DARM OLTF for H1 (LHO#17153), we see that we easily have more room for a boost below 10 Hz or so (and Dan is already working on this).

Also attached are spectra of recent "best" locks from H1 and L1, along with the GWINC prediction for 10 W of input power.

P.S.: The rms traces of the calibrated DARM signals in DTT appear to be completely bogus. The attached plot was done independently in python.

P.P.S.: Attempting to print these spectra in pdf, eps, or ps causes DTT to crash.

Dan, Sheila

We had a quick look at last night's lock, it seems that the degradation in the range over time was not due to an alingment drift, since we can see that the build ups stayed high durring the lock.  It seems like the wind picking up again this morning was pretty well correlated with the range decreasing.  We don't know how to get DMT sensmon data (or any DMT data) from the control room. Dan made this plot by logging into the cluster to find the DMT sensmon frame files.  

Dan, Sheila

The attached screenshot shows a one second trend of the beckhoff channel that is the fast shutter trigger readback, along with two RCG channels, the first is AS_C sum, this PD should be the source for the fast shutter trigger, and ASAIR_LF,  which should see similar power fluctuations.  

The beckhoff channel seems to be 0.2 seconds ahead of the RCG channels.  This timing difference sometimes makes it appear as though the fastshutter shut first, causing the lockloss, as in the second attached screenshot. 

We would like to prove definteively that the shutter is only shutting when it should, but we don't have a readback that we trust.  

Following up on my log 17295, the 10 hz CPS low pass elliptical filter is now running on all BSC ISI's. I've spent today working on ETMX trying to push the St2 filter down more and adding a similar filter to St1 but it's not ready for show time, so only the "old" filter mod is running.

First attached plot shows the X and Y St2 sensors, X is red ( gnd STS, St2 CPS& GS13), Y is blue, Y is running the "old" elliptical filter, X is running the more aggressive setup. You can see that from ~2 to 15 hz the more aggressive (red) setup does better. Unfortunately, the St1 elliptical filter interferes with the sensor correction (changing the phase of the CPS plant), so the ground STS signal doesn't cancel the CPS signal as well, increasing motion by ~2x at ~.5 hz. Or maybe the ground is a little worse, idk. I plan on tuning this a little more, maybe modifying the sensor correction as well (when I understand it better), and will try again when the opportunity presents itself.

The next two plots show changes I've made to the blends. Second plot is St1, red is stock, green is the filter I tried today(with problems at .5 hz), blue is what I will try next.

Third plot is St2 blends, red(not installed) is new, blue is the only thing running right now.

model restarts logged for Mon 23/Mar/2015

no restarts reported

Time Code Translator work at end stations, WP5116

Dave, Jim:

We racked up the missing TCT in EY, then connected it to one of the unused fiber pairs running between the VEA rack and the computer rack. We verified it was using ports 19 and 20 in the MSR (same as EX). Once connected the TCT synced to the time and the error LED on the MSR sender was extinguished.

We then ran 30 foot 50-Ohm coax, BNC terminated, between the TCT in the computer rack, through the wall, to the first port on the CER comparator. This was done at both EX and EY. The 1PPS port on the back of the TCT is a TNC connector, so we used a TNC-BNC adapter on that port for EX. We need to do the same for EY.

At EX, the comparator is now displaying a time of -22.2uS on the TCT port, roughly the time of flight between the buildings. We will revisit the TCT internal settings, they are most probably what was left from iLIGO.

Rebuild of ASC model

Daniel, Dave:

Daniel though h1asc would benefit from a clean build, install and restart. This was done, I'll see if this helped in the IPC errors.

PCAL filter modules, port from PEM file

Sudarshan, Dave:

Sudarshan discovered that I had forgotten to migrate the PCAL filters from when the CAL system shared a core with the PEM. He copied them from H1PEME[X,Y].txt to H1CALE[X,Y].txt, making a CAL_PCAL to PCAL name change in the process. The filters were then loaded into the PCAL models at both end stations.

(Kyle, Gerardo)
Turned off and decoupled two pump carts, from HAM1 and HAM2 annulus system.
The annulus ion pump for HAM1 still not connected to CDS, HAM2 is.

Scott L. Ed P. Chris S. Joe D.

Completed tube cleaning to single door between X-1-6 and X-1-7, 40 meters today. Test results for cleaned section and next dirty section are posted here.
Installed 70 support tube caps on previously cleaned sections and more on order. 
Continuous monitoring of beam tube pressures by control room operator during cleaning operations. 

Since we are frequently running out of range on the end station VCOs, when there is high wind, we switched the drive of the fiber AOM back to the IMC VCO. This was the original scheme. It has the disadvantage that the end station green locking now depends on the IMC to be locked. On the other hand, this is probably not a big deal, when working with the fully locked interferometer.

07:00 Cris and Karen into LVEA

08:08 IFO Fully locked at LOWNOISE_ESD_ETMY - ~18Mpc.

08:15 Gerardo into LVEA

08:25 Gerardo out of the LVEA

08:49 Joim installing new isolation filters on BS

08:49 Heintze out to LVEA -TCS

08:57 Gerardo out to LVEA - HAM1

09:08 Corey out to squeezer bay 

09:14 Ellie out to LVEA - HAM1 area

09:18 Betsy out to LVEA

09:21 Jim W and TJ to EX

09:30 Jim B to EY to install Time Code Translator.

09:21 Jim W and TJ back from EX

09:53 Gerardo out of LVEA - Fil and Andres are still in pulling RF cables around HAMS 3,4

10:00 Jodi and Gary out of the LVEA

10:23 D Barker and J Batch back out to EY

10:25 HFD on site

10:58 Doug Cook out to LVEA - running a box of parts out to a cabinet.

11:08 P King into H2 enclosure

11:15 D Barker restarting ASC

11:42 P King out of H2 enclosure

12:07 Matt outnof LVEA

12:08 Dave amd Jim back to EX

12:10 Fil and co. out of LVEA

12:38 Dave and Jim back from EX - DAQ restart imminent 

12:42 DAQ restart

12:56 Karen @ EY

13:43 Karen Leaving EY

14:50 Fill out to LVEA to make some  measurements for cables

15:00 Kyle and Gerardo to MidX

15:07 Fil out of LVEA

This is the analysis of a quiet stretch of data in SR3 oplev from yesterday. 

I checked to make sure of the following:

a) Alignment sliders have not been moved during this period 

b) There is no actuation to SR3 at this time. 

c) The signal levels on all SR3 quadrants are okay, that is the quadrants are not saturated. 

I am posting here screenshots of plots of:

1) the time series for 16 hrs at 1 sec sampling rate

2) the time series for a 2 hr stretch with 256 Hz sampling from within the 16hr stretch

3) a RIN spectrum of the SUM signal for the 16 hrs sample going down to 10^-3 Hz to 0.1 Hz

4) a RIN spectrum of the SUM signal for the 2 hrs sample going from 0.1 Hz to 100 Hz

5) A spectrogram of the 2 hrs signal showing the broadband noise injections due to the glitches in the laser.

Note:

All data for this analysis is available in /ligo/data/oplevs  at LHO. File name LHO_SR3_before_LD_Fix.mat

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.