As per the earlier alog for ETMY BRS sensor correction aLog 27941, 
I ran offline date (the same 5 hours stretch) through sensor-correction filters in Matlab, trying to optimise the subtraction and improve the 
low frequency velocity RMS.

As per the Y-arm, we reach BRS sensor noise by about ~15-20mHz, and we can gain a factor of a few at 1mHz, and improve subtraction between 10 and 100mHz.

Performance is shown in the attachment. The black curves show the GND-STS2 output, the blue curves show the GND 
output corrected for tilt by the BRS using the previous filters. The red curves show the performance with new sensor correction filters. 
In all cases, RMS is only accrued below 0.1Hz to exaggerate the differences. The Magenta curve shows the approximate BRS noise floor, but this 
still doesn't seem quite right below 10mHz.

Coherence is pretty much as per ETMY.

Change summary:
- Moved the zero in the 'Torque' filter bank from 0.1mHz to 0.
- Moved the high-pass filter. In this case, I found 6.2mHz gave the best subtraction.
- Moved the acc-to-vel pole from 2->1mHz.
- Changed the match from 0.79 to 0.87.
- Moved the pole in 'Zero_Inv' from 0.5mHz up to 3mHz.

We plan to change to use the ETMY ESD drivers with lower range and lower noise. To make sure that this will not saturate the drivers, we measured the spectrum of ETMX, and calibrated it with ESD OUTPUT filters, which are different for ETMX and ETMY. This should be fine because the calibrated magnitude is lower than 1000 cnts, which is much smaller than the driver's range (~130000 cnts).

We've been talking about blending 2 different combinations of TransMon QPD signals for our SOFT loops:  TransMon insensitive at low freqs, and HARD insensitive at higher freqs.  So, I've added filter banks for the SOFT loops to match those that already exist for the HARD loops.  This is WP#5963.

Evan G., Darkhan T.

Summary:
Foton filter coefficients have been updated for Y-end calibrated Pcal TX and RX outputs and X-end calibrated Pcal TX output. X-end RX output is unchanged because it is still affected by a clipping issue. Until the clipping is fixed, the X-end RX PD channel currently has an incorrect calibration. Our plan is to fix this before O2.

Details:
Several end station Pcal calibrations have been made since the last update for the N/V foton coefficients. The general formula for this coefficient is: N/V = 1/[ TX/WS x WS/GS x GS ] x 2 x cos(theta)/c

We compute below the new coefficients.

Y-end:
From the trend of calibrations (T1500131-v4) made since Aug 2015 to May 2016, the mean value of the ratios for TX and RX to WS accounting for optical efficiency losses is:
  TX/WS = -2.7619 V/V
  RX/WS = -3.9891 V/V

X-end:
From the trend of calibrations (T1500129-v7) made since Aug 2015 to May 2016, the mean value of the ratios for TX to WS (not corrected for optical efficiency losses) is:
   TX/WS = -3.154688 V/V
Using the only reliable optical efficiency we have, D20150804 in T1500129-v7:
   e = 0.982588
Computing the TX/WS ratio accounting for the optical efficiency is:
   TX/WS = 2/(1+0.982588) * -3.154688 = -3.1824 V/V

Working Standard:
Using the trend of working standard calibrations (T1500054-v41), the WS to GS ratio is:
   WS1/GS = 0.926745 V/V

Gold standard:
Using the two calibrations from NIST on Aug 12, 2014, and Dec, 17, 2015 (T1500036), the mean value of the GS responsivity is:
   GS = -1.7000 V/W

Power-to-force:
The power to force coefficient is 2*cos(theta)/c, where theta is the angle of incidence and c is the speed of light. From L1600019-v1, the mean of cos(theta) is 0.9884

Final results:
   Y-end TX = 1.515e-9 N/V
   Y-end RX = 1.049e-9 N/V
   X-end TX = 1.315e-9 N/V

These new values have been loaded into Foton and updated the EPICS records

Daniel, Ross, Carl, Kiwamu,

WP#: 5957

We made two modifications on the h1omspi, h1susetmxpi and h1susetmypi models as follows.

• We added all the I and Q down sampled channels to science frame at 2 kHz.
• We added two new OMC DCPD signals which don't get attenuated by two 10 kHz poles of the whitening circuits.

We are ready for tomorrow's model restart during the maintenance period.

[I and Q signals to science frame]

Since all the I and Q down sampled signals have been already recorded in commissioning frame, we just added a star symbol to each channel name in the DQ text field in the simulink models. In total, 24 channels (8 channels from each model) will newly go to science frame at 2 kHz.

[New DCPD signals]

We decided to do a quick hack on the OMC whitening board so that we don't suffer from the two 10 kHz poles (technically, 14 and 18 kHz from the differential receiver stage, see alog 21131) to obtain a better signal to noise ratio. Some more details of this quick hack will be reported by Daniel and Stefan later. In the mean time, we have edited the h1omcpi model so that it is capable of handling these two signals. In the first attachment it shows the two new ADC inputs (adc_0_14 and adc_0_15) which then go to a subblock called PI_DCPD. One can choose whether the normal DCPD is used for the PI error signal or the new signals by the two choice blocks that are behind the PI_DCPD block.

Once we become able to damp the PI modes using the new DCPD signals, we should get rid of the old DCPD signals. But for commissioning purpose, we are leaving the normal DCPDs available for now.

Also, we added these two new signals to commissioning frame at the full sampling rate at 64 kHz. So, in total, we now have four 64 kHz DQ channels, which should be reduced to 2 or 1 channels as we complete the commissioning at some point in future. The new DQ channels have the names as PI_DCPD_64KHZ_A(B)HF. Note that in order to save the test points for the normal DCPD signals, we pulled them out of a subblock and placed them at the top level as seen in the first attachment.

In the PI_DCPD subblock, we have placed controlled-IIR-fitlers so that they can be synchronized with the analog board settings as have been done in the LSC and ASC models. See the second attachment.

All the changes are checked into the SVN repo. We made sure that they compiled without errrors.

J. Kissel

Summary
We're adding three new calibration lines around 30 Hz on the ETMY actuation stages in order to narrow down the uncertainty in actuation strength independently for each stage. Depending on the success of their analysis, and interference with IFO operations, we'll decide whether to leave them on for ER9. We may also push further forward with cancelling these lines with the Y-end PCAL, but for now, I turn them on without cancelling for the week prior to ER9. We may also push further forward an cancel these lines with the Y-end PCAL, but for now, I turn them on without cancelling for ER9.

Motivation
Recall that during O1, H1 had a static, ~2% systematic error in the collective actuation strength ("kappa PU"), narrowed down using cumulative integration time allowed for by the overall DARM loop line coupled with the ESD-only line (see e.g. LHO aLOG 24569 or LHO aLOG 25031). We intend to differentiate between the strength of the upper stages for the future, using their constant presence to bring the uncertainty in relative actuation strength to be essentially zero. Once we cancel these lines with PCAL, that'll bring the absolute calibration uncertainty to essentially zero.

Line Details
For now, without the man-power for further study of their "optimal" location, I've just stolen L1's ~30 Hz calibration line frequencies from O1 (see original source T1500377), given that they'll not be involved in ER9. The details of the new lines are:
Isolation Stage        Frequency        Amplitude     Oscillator Channel
TST / L3                 35.3              0.11       H1:SUS-ETMY_L1_CAL_LINE
PUM / L2                 34.7              1.1        H1:SUS-ETMY_L2_CAL_LINE
UIM / L1                 33.7              11.0       H1:SUS-ETMY_LKIN_P_OSC

These new values have been accepted into the DOWN and SAFE SDF files.
This is in addition to the "normal" calibration lines from O1 that will still be on such that we can replicate the O1 calculation without extra effort.

On the TST / L3 stage, we now have *two* calibration lines, and this is such that we can still reproduce the O1 calibration line, time-dependent parameter tracking without changing anything. However, because we're not yet confident enough in the PCAL cancelling scheme for it to completely replace the O1 method, and we haven't installed / replaced any infrastructure. Thus, for now, I've stolen one of the Optical Lever Lock-in Oscillator and piped it out to the DAC output as a longitudinal drive using the LKIN2ESD matrix. 

Below are the past 10 day trends. There seems to be some correlation in a decrease of XTALTEMP in the last couple of days with an upward trend in PSL-AMP "D" power as well as PSL_PWR_HPL_DC_LP OUTPUT. It is possible that these fluctuations are being facilitated by the change in Chiller action (for the better) over the past couple of days.

As usual, for further in depth analysis please direct to Jason O and Peter K.

Chiller questions may be directed to Jeff B.

J. Kissel,

Not sure why (couldn't find a aLOG), but the SDF system found that the PCALY calibration lines at 36.7, 331.9, and 1083.7 have been off since Monday Jun 20. I've turned them back on, such that we can get as much information about this week's lock stretches as we can. This was done by setting the SIN and COS amplitudes back to 125, 2900, and 15000 [ct] respectively.

CP5 has a couple features that are unique to the other CPs:

1. The Dewar exhaust pressure regulator was adjusted to raise the Dewar pressure from 15 psig to 19 psig (one turn on regulator bolt head).
2. The upper end of the electronic actuator was "zeroed" at full range of device rather than where it landed when CP5 was set to 100% open. 

We added the range and increased Dewar pressure because in order to maintain 92% full the LLCV setting was historically around 88% but has drifted to 98-100%. 

Added 904 channels. Removed 410 channels. (see attached)

Flow meter is connected to CP4 exhaust again. Readings are bogus negative values. Will need to send back to company for recalibration and possibly sensor replacement, after freezing device last week with unexpected LN2 surge out the exhaust.

Applied LOCTITE Threadlocker Blue 242 nut & bolt locker to the LLCV shaft and actuator coupling nut and re-zeroed the device (no room for a lock nut on shaft).

20 sec. to overfill CP3 with 1/2 turn open on LLCV bypass valve

SEI
BRS commissioning continues
reinstall anemometers at wind fence

SUS
OSEM noise hunting
swap of 18 bit DACs that fail autocal Tuesday

PSL
looking at flow/pressure issue, drop in temp, jump in flow

FAC
property service inventory Tuesday, in LVEA, VEAs

VAC
apply Loctite to CP LLCV values Tuesday

PI
model modification Tuesday

EE
retrieval of VAC VME chassis for excess Tuesday

Other
2 visitors in staging building working on PMC
Tour scheduled Tuesday afternoon, in LVEA

I have remotely restarted h1nds1 via the management port. It look like the machine probably kernel panic'ed. If it happens again today please call me on my cell phone so we can capture the error message before restarting.

From h1nds1 logs, daqd crashed at 11:30PDT Sat morning. It was processing a second-trend request to retrieve 6 hours of data (actually it looks like two identical requests one second apart).

[Sat Jun 25 11:28:59 2016] ->12: start trend net-writer "7000" 1150892875 21600 { "H1:IMC-PWR_IN_OUT_DQ.min" "H1:IMC-PWR_IN_OUT_DQ.max" "H1:IMC-PWR_IN_OUT_DQ.mean" }

[Sat Jun 25 11:28:59 2016] ->23: version

[Sat Jun 25 11:29:00 2016] ->23: revision

[Sat Jun 25 11:29:00 2016] ->23: status channels 3

[Sat Jun 25 11:29:00 2016] connected to 10.22.0.108.22811; fd=32

[Sat Jun 25 11:29:00 2016] ->23: start trend net-writer "7001" 1150892875 21600 { "H1:IMC-PWR_IN_OUT_DQ.min" "H1:IMC-PWR_IN_OUT_DQ.max" "H1:IMC-PWR_IN_OUT_DQ.mean" }

h1fw1 continues to be stable, 1 day 18 hours now.

Stefan, Lisa

We leave the interferometer locked at 40W, starting at Jun 26, UTC 3:32

The only things done by hand are SOFT offsets and SRM alignment (as last night, the SRM alignment loops is left open), and the PI damping (we have the PI damping loops on as described in the previous log).

Jenne, Lisa, Stefan,

Still running at 40W, for 2h.

Tried to damp some PIs and go to low-noise.

- We successfully damped 15009Hz (ETMY) and 15542Hz (ETMY) (damp settings picture attached.)

- 15541Hz (ETMX) was ringing up.So we tried switching to ETMY and transition the ETMX coil driver to low noise.

- We successfully switch the coil drivers, but...

- We switched to ETMY, low noise, held lock for a while, but saturated the ETMY ESD with 20Hz noise from the ASC, as well as a 532.77Hz line, that we don't know the origin off. (PI?) (picture)

===================================

Also, we realized that DTT is a bit too smart: The 64kHz channel H1:OMC-PI_DCPD_64KHZ_A_DQ can in principle look at PIs above the Nyquest through aliasing. However, since DTT only alows you to select a freqency about 10% below the Nyquist frequency, there is an effecive dead band where DTT cannot see PIs between ~29500Hz and ~36036Hz. The MATLAB script below produces a spectrum up to the Nyquist. Indeed, we found an elevated mode at 30018.3Hz, although it was not quite saturating.

MATLAB code to get spectrum up to Nyquist frequency:

addpath /ligo/svncommon/NbSVN/aligonoisebudget/trunk/Externals/SimulinkNb/Utils/
gwd = GWData();
gwd.make_kerberos_ready;
gwd.site_info(2).port = 31200;
gwd.site_info(2).server = 'nds.ligo-wa.caltech.edu';
H1.channels = {'H1:OMC-PI_DCPD_64KHZ_A_DQ'};
time_fetch = tconvert('26 Jun 2016 01:15:00');
[data, t, ~] = gwd.fetch(time_fetch, 1000, H1.channels);
Fs=4*16384;
pwelch(data,[],[],[],Fs)
 

We are seeing 8 peaks in at least two of the horizontal mechanical mode groups (instead of the expected 4, one for each test mass).

Below are spectra of the two mode groups as seen in the OMC DCPDs, taken while locked at 2 W and 20 W. 

Compared to the 15000 vertical mode group here.

When I drove the 15070 Hz group: 

• Driving ETMX with +/- 60 deg phase alternately rings up 15070.5 and 15073.5
• Driving ETMY with same - 60 deg phase and same sign rang up 15072.7 and 15066.6; flipping phase moved 15066.6 peak to right ~1  Hz
• Driving ITMX with opposite signs alternately rings up and damps 15063 and 15077 (alog 27659)

When I drove the 15600 Hz group:

• Driving each test mass with a wide BP over the whole mode group and trying different phases only rang up one peak each
• Driving ETMY rings up 15627.5 but also 15542 just as strongly, even though the latter is supposedly part of an orthogonal mode group 

See wiki for frequencies I was able to drive and thus assign to a specific test mass.

Ideas:

• Mode splitting due to asymmetries in the test masses from ear placement, etc. However, Carl and Slawek both independently failed to see this result when adding asymmetries to their models. 
• Violin mode coupling. However, by these high frequencies violin mode harmonics would cover a wide spread; would they not be just as likely to be seen in any mode group?
• PUM mechanical mode resonances coupling through the violin modes.