Nutsinee, Stefan

As suggested by alog 31304, we set up a 26:74 mixed input matrix element for PRCL in the next lock:

POP_A_RF9_I to PRCL = 0.0091
REFL_A_RF45_I to PRCL = -849 (yes, a minus sign)

This gave us the expected additionbal slight improvement in PRCL sensing, see the attached plot.

Indeed, this auxiliary noise reduction seems to have given us a range increase of about 5% to 75Mpc.
More importantly though, suddenly the range seemed to be rock-sold, without any up- and down drifts - see the last hour in the attached range plot.

Still to do: PRCL FF & possible modulation depth increase.
After this first step the return will not be as big in terms of range, but the improvement in range stability by itself makes it worth the effort.

We put all this into Guardian (NOISE_TUNINGS), but we didn't test the Guardian yet (the interferometer was too steady).

We did a final CO2 exploration at an input laser power of 25 W today. This was to fine-tune the CO2 settings that the operators have explored in the past weeks (31048, 30974).

• Increasing the CO2X power improves 350 Hz and 610 Hz peaks while it makes noise worse at almost all other frequencies in 100-1000 Hz.

In the end I set the CO2X power back to 0.3 W (which was recently set 31246) which gave us the highest BNS range. Not sure if the addition of the IMC WFS offset (31246) changes the story here.

[The test]

The TCS test started at around 19:14 UTC today. The interferometer has been locked for more than 10 hours at that point with an input laser power of 25 W. The CO2 settings before the test was [CO2X, CO2Y] = [300 mW, 0 W]. This is something Sheila set during the weekend (31246). Here is an imcomplete list of time lines.

• 19:14 UTC (CO2X; 300 mW -> 600 mW) [REF0]
• 19:38 UTC (CO2X; 600mW -> 800 mW)
• 19:50 UTC [REF1]
• 20:20 UTC [REF2]
• 20:50 UTC [CO2X; 800 mW -> 500 mW]
• 20:56 UTC [CO2X; 500 mW -> 0]
• 21:10 UTC [REF3]
• 21:52 UTC (CO2X; 0 -> 300 mW)
• 22:00 [REF4 or live]

In the above list, the letters in the square brackets correspond to the labels in the dtt spectra shown below. A trend of this test are shown in the first attachment. LOCKINs 1 and 2 were monitoring the coupling transfer coefficients from the PSL periscope PZT to DARM for pitch and yaw, respectively. The pitch excitation was at 441.3 Hz and the yaw was at 421.1 Hz.

[The results]

The DARM spectra from different times are shown below.

As the CO2X increased, noise around 350 Hz and 620 Hz decreased. This behavior is qualitatively consistent with what I have seen in the LOCKIN demodulators, especially the yaw coupling or LOCKIN2. However, obviously, this improvement came with higher noise elsewhere. In particular, the 260 Hz peak became quite noticeably worse by a factor of 3 at most. Also, the side lobe of the 1 kHz violin modes became significantly worse too by a factor of roughly 2. This time, I did not check laser noise couplings (intensity or frequency) simultaneously. According to the sensmon shown in the first attachment, increasing CO2X decreased the BNS range by 5 Mpc or so. The DARM spectrum below 100 Hz seems to have stayed the same throughout the test.

J. Kissel

I've taken the first round of all swept sine measurements typically done before an observing run:
(1) Sensing function, C
    (a) DARMOLGTF and Loop Suppression (IN1/IN2 and IN2/EXC); G and 1/(1+G)
    (b) PCAL2DARM (and PCAL2DELTAL); (C/1+G) and [m/m]
(2) Actuation Function, A
    (a) L1 to DARM & associated PCAL2DARM; (C A_uim)/(1+G) and (C/1+G)
    (b) L2 to DARM & associated PCAL2DARM; (C A_pum)/(1+G) and (C/1+G)
    (c) L3 to DARM & associated PCAL2DARM; (C A_tst)/(1+G) and (C/1+G)
where I've taken a separate PCAL2DARM or C/1+G transfer function with every corresponding excitation to destroy any covariance that had plagued us during O1. Also, I've worked to
    (i) reduce the template's measurement time by maximizing drive, 
    (ii) reducing the number of points over all, and
    (iii) keeping integration time in check,
such that each template only takes about 15 minutes. I've also modified the frequency vectors of the actuation functions to go out to 1 kHz, as LLO did for their O1 data sets. In doing so, I made sure to use frequency points that avoided any known high-frequency resonances from wire violin modes (characterized in LHO aLOG 24917). 

There's still some improvements to make, which I'll shoot for in the next round (so don't use/take these templates as cannon yet), but thanks to the high-duty cycle of the IFO, I had the opportunity to make really well-balanced templates tonight.

The data lives here:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/ER10/H1/Measurements/
(1a) DARMOLGTFs/2016-11-07_H1_DARM_OLGTF_4to1200Hz_fasttemplate.xml
(1b) PCAL/2016-11-07_H1_PCAL2DARMTF_4to1200Hz_fasttemplate.xml

(2)
FullIFOActuatorTFs/2016-11-07/2016-11-07_H1SUSETMY_L1_iEXC2DARM.xml
FullIFOActuatorTFs/2016-11-07/2016-11-07_H1SUSETMY_L1_PCAL2DARM.xml
FullIFOActuatorTFs/2016-11-07/2016-11-07_H1SUSETMY_L2_iEXC2DARM.xml
FullIFOActuatorTFs/2016-11-07/2016-11-07_H1SUSETMY_L2_PCAL2DARM.xml
FullIFOActuatorTFs/2016-11-07/2016-11-07_H1SUSETMY_L3_iEXC2DARM.xml
FullIFOActuatorTFs/2016-11-07/2016-11-07_H1SUSETMY_L3_PCAL2DARM.xml

While it'll be days before we have a model and a complete, traceable uncertainty budget, preliminary results show the *mean* of *one measurement* of PCAL's estimated displacement agrees with the front-end calibrated sensitivity to roughly 5% and 5 [deg]. This confirms that the > 50 Hz discrepancies between PCAL and DELTA L EXTERNAL seen while we were at 50 [W] (e.g. LHO aLOGs 30391 and 30431) were likely a function of the poorly controlled signal recycling cavity, and therefore time-dependent RSE cavity pole that was quite low.
Recall that the uncertainty of the PCAL estimation is around 1%. 

We're right on schedule, and things are looking up. We'll see how the modeling goes...

I succeeded in switching PRCL over to REFL_A_RF45_I.

This improved the sensing noise between 30Hz and 100Hz by about a factor of 2.

We did this in the middle of an earthquake, and eventually lost lock, so I didn't put it in Guardian yet. We also had more than usual scattering due to the earthquake, so it is too early to tell whether it made a DARM noise difference.

Also:

- We should investigate increassing (or better: not reducing) the RF45 modulation index.

- By mixing POP_A_RF9_I and REFL_A_RF45_I to PRCL by about 0.26:0.74 we should get another ~25% shot noise reduction.

- The first lock looked promising, but if for some reason we still have a DC drift problem on REFL, we could blend it to POP_A_RF9_I at DC

Matrix elements:

replaced the old

POP_A_RF9_I to PRCL = 0.035

with the new

REFL_A_RF45_I to PRCL = -1147.5 (yes, a minus sign)

J. Kissel

The duty-cycle has been delightfully high, so we've been able to get the two hours needed for 1001.3 Hz data point of the roaming high-frequency calibration line quickly despite this mornings issues (see LHO aLOG 31288). Thus, I'm changing it to the much more time intensive 4 kHz line. 

Here's the latest status: 
Frequency    Planned Amplitude        Planned Duration      Actual Amplitude    Start Time                 Stop Time                    Achieved Duration
(Hz)         (ct)                     (hh:mm)                   (ct)               (UTC)                    (UTC)                         (hh:mm)
---------------------------------------------------------------------------------------------------------------------------------------------------------
1001.3       35k                      02:00                   39322.0           Nov 11 2016 21:37:50 UTC    Nov 12 2016 03:28:21 UTC      ~several hours @ 25 W
1501.3       35k                      02:00                   39322.0           Oct 24 2016 15:26:57 UTC    Oct 31 2016 15:44:29 UTC      ~week @ 25 W
2001.3       35k                      02:00                   39322.0           Oct 17 2016 21:22:03 UTC    Oct 24 2016 15:26:57 UTC      several days (at both 50W and 25 W)
2501.3       35k                      05:00                   39322.0           Oct 12 2016 03:20:41 UTC    Oct 17 2016 21:22:03 UTC      days     @ 50 W
3001.3       35k                      05:00                   39322.0           Oct 06 2016 18:39:26 UTC    Oct 12 2016 03:20:41 UTC      days     @ 50 W
3501.3       35k                      05:00                   39322.0           Jul 06 2016 18:56:13 UTC    Oct 06 2016 18:39:26 UTC      months   @ 50 W
4001.3       40k                      10:00                   39322.0           Nov 12 2016 03:28:21 UTC
4301.3       40k                      10:00       
4501.3       40k                      10:00
4801.3       40k                      10:00  
5001.3       40k                      10:00

Plot 1 shows the ASC coherence during an imperfect A2L strech this morning. this resulted in a power-law increase in DARM below 60Hz.

We designed slightly more agressive cut-off filters for DHARD_P, CHARD_P and CHAD_Y. They , take the ASC signal below other noise above ~35Hz, even if the A2L tuning runs away a bit.

Plot 2 shows the the new (sold) and old (dashed) drive levels of the ASC.

The new filters were integrated with the ELP10 filters for DHARD_P and CHARD_P (FM4 and FM2 respectively). For CHARD_Y I copied the cut-off filter from FM9 to FM3 before modifying it in FM3. This preserves the old 40W cut-off filter. I switched Guardian over to use FM3. The new filter uses less than 7deg extra phase at the UGF. The last 50W transfer function measurment suggest that we have about 60deg at the UGF, so the filter should also work at 50W.

The ISC guardian was again checked into SVN after the modification.

Rick S, Sudarshan K, Travis S, Jeff K, Darkhan T,

We uploaded the updated force coefficients (N/V) into the PcalY filter file. This has effect on following calibrated outputs:

H1:CAL-PCALY_TX_PD_OUT*
H1:CAL-PCALY_RX_PD_OUT*

Calculation of the factors is described in T1600520-v1. Relevant sources (other T documents containing WS, GS and end-station calibrations) were referenced in that document. The Matlab script that produced the factors is attached to the document above and also can be found in CalSVN (or a newer version of the script in the same directory):

https://svn.ligo.caltech.edu/svn/aligocalibration/trunk/Projects/PhotonCalibrator/scripts/pcalEndstation/pcalForcecoefficient.m

The old and new values are listed below:

• TxPD: old value 1.515^-9 N/V, new value 1.516^-9 N/V, changed by 0.07%.
• RxPD: old value 1.049^-9 N/V, new value 1.0475^-9 N/V, changed by 0.14%.

One can notice that these values are nearly identical, which is a mere coincidence. We consider PCALY is now in a new epoch w.r.t. O1 time because we adjusted beam positions on the ETM (also addressed clipping at RxPD integrating sphere) and we adjusted the angle of the transmitter module beamsplitter which adjusts the power balance between the two beams (see LHO alog 30877).

• 16:24 Intent Bit was dropped to Commissioning.  Asked around the Control Room & no one confessed.  Hugh was working on SDF stuff but we don't think it was that.  I could have sworn I saw a PEM_MX excitation Message on the DIAG_EXC by chance.  Looking at the DIAG_EXC node's log, I see there is a mention of:  "EXC:  pemmx excitation!" at 16:24:09 & 16:25:37.  What is this??
• 17:36 Out Of Observing for A2Ls
• Went in/out of Observing whenever available...don't want to list every time.
• 18:15  Input Beam Pointing test (Kiwamu)
• 18:30 TCS Settings test (Kiwamu)
• Looked at ETMx 2nd Harmonic violin modes
• 21:34 Hanford Fire going to EY to check RAFAR alarm
• 22:46 LOCKLOSS! (after 15hr30min lock)----> Possibly a 5.6mag Indonesia earthquake which Terramon said would arrive a few minutes earlier than our lockloss time.  (L1 also dropped out...as predicted by Terramon.
• 22:50 Hugh addressed SDF DOWN snapshots (mainly for SDF nodes in the "LSC Column" on the SDF Overview.
• 23:07 CP3 fill (Chandra)
• 23:58 Made it back to NLN after 2nd attempt & handing over to Nutsinee.  She is going to run the A2L for this lock.

3:30 pm local

Took 75 seconds to overfill CP3 by increasing LLCV from 20% open to 50% open. Attached is 1 hr plot in seconds showing TC temp fall, and the last several fills.

From Stefan's offline request, I ran bruco on two times,

Nov. 07, 2016, 19:30:00 (GPS time : 1162582217):

on DARM:  https://ldas-jobs.ligo-wa.caltech.edu/~youngmin/BruCo/PRE-ER10/H1/Nov07/H1-DARM-1162582217-600/

on MICH: https://ldas-jobs.ligo-wa.caltech.edu/~youngmin/BruCo/PRE-ER10/H1/Nov07/H1-MICH-1162582217-600/

on PRCL: https://ldas-jobs.ligo-wa.caltech.edu/~youngmin/BruCo/PRE-ER10/H1/Nov07/H1-PRCL-1162582217-600/

on SRCL: https://ldas-jobs.ligo-wa.caltech.edu/~youngmin/BruCo/PRE-ER10/H1/Nov07/H1-SRCL-1162582217-600/

Nov. 07, 2016, 16:30:00 (GPS time : 1162571417):

on DARM: https://ldas-jobs.ligo-wa.caltech.edu/~youngmin/BruCo/PRE-ER10/H1/Nov07/H1-DARM-1162571417-600/

The PMC length noise no longer shows up in DARM. Even for the 1 kHz and 4 kHz peaks there is a factor of a few safety margin. Increasing the PMC gain slider from 0 dB to 16 dB (actually from 0 dB to 12 dB), we see no significant change in DARM. The 4 kHz peak starts touching the noise floor with a 0.3 coherence.

Readjusted the REFSIGNAL (diffraction power) and AC offset for the ISS second loop. New values in SDF (down).

Sheila has mentioned Operators should take a look at squashing down some of the 2nd Harmonics of the Violin Modes.  Using Nutsinee's procedure, I went about taking a First Look.   Attached you will see a power spectrum during our current 10+hr lock.  On here we get the following which are above a 10/23/16 reference:  (freq & wiki notes)

• 1003.78 (ETMx, No Filter Bank Mode?)
• 1005.94 (ETMx, No Filter Bank Mode?)
• 1009.44 (ETMy, Mode10)
• 1009.48 (ETMy, Mode10)

Decided to look at ETMx's 1005.94.  On its Damping Filter medm, we had a filter bank already set up for this:  MODE10.

1005.94Hz

• MODE10
• Gain:  -200  (this is a change)
• -60deg (no change)
• 100dB (no change)
• FM7 (1005.938) (change)

This squashed this line.  This has been entered in the Violin Mode wiki.

Addressed the next biggest line of 1003.78 for ETMx.  This is taken care of in MODE9.  A positive gain rung it up, so tried some negative gains which was fine.  Then I tweaked phase from -60deg and went to 0deg.  This was fine.  Unfortunately, when I tried a gain of +60deg, this rung it up.  And it looks like it excited the neighboring line of 1003.667.   I've been trying to now damp out the latter (1003.667), but it is going reeeealllly slow.

Since I wasn't successful with the 1005.94, I will not make a note of what I attempted and won't update the wiki.

Repeating the same idea as we did for frequency noise in aLog  31176
we measured the sensitivity of REFL_A_RF45_I, POP_A_RF9_I and POP_A_RF45_I to PRC length noise, and then used this transfer function to project the noise into DARM.
(REFL_A_RF9_I is used for the CARM loop -so there is no interesting signal there.)

Around 40Hz the three projections basically agree, and are a factor of 2 below the noise floor. Also, it seems that REFL_A_RF45_I would actually have a lower noise floor than POP_A_RF45_I. We should consider using it for PRCL.

FInally, we should implement a PRCL_feed-forward path.

The templates for the measurment are here:

/ligo/home/controls/sballmer/20161107/PRCLNoiseProjection.xml
/ligo/home/controls/sballmer/20161107/REFLPOPV4.xml
 

J. Kissel, D. Tuyenbayev

Following preliminary results from Darkhan on the individual actuation strength of the UIM and PUM stages for H1SUSETMY (see, thus far LHO aLOG 31275), and the current delightfully long lock stretch with them in place, I'm bringing this study to a close. I've turned off the temporary L1 and L2 calibration lines at 33.7 and 34.7 Hz, respectively. We do not intend on turning on these lines again for the duration of the run.

These lines were turned OFF at Nov 07 2016 21:21:49 UTC.

J. Kissel, D. Tuyenbayev

We're still not getting the IFO duty cycle to get the desired uncertainty on the single-frequency actuation strength scale factor measurement of the UIM and PUM stage and we're running out of time, so I've increased the SNR of these temporary lines by another factor of ~3 over yesterday's increase (see LHO aLOG 31108).

Oscillator       Freq (Hz)      Old Amp (ct)   New Amp (ct)
ETMY UIM          33.7           180            500
ETMY PUM          34.7            81            300

Hopefully Robert's activities tonight won't impact the ~30 Hz region of the sensitivity, and we can turn things off soon.

A while ago we saw that negative 400 volts reduced the 60 Hz line in DARM by a factor of 2.  (30778)

We just checked again and this is still true and now the guardian will set in the guardian state low noise etmy esd.  We are doing this using the gain in the bias filter bank so that the bias choosen to mitigate charge will still be use whenever we aren't locked. 

Started yesterday evening. Doesn't seems to be equally spaced.