[Sheila, Keita, Jenne, Patrick]

We have been struggling to lock anything at all today.  Sheila is going to post about the loop measurements that we made today, but this alog is a cry for help with regard to the ISS. 

The ISS average diffracted power has been much more noisy than usual, ever since Friday.  Since today's PSL work, it's even worse.  We suspect that this may be bad enough that we are unable to lock.  We can no longer keep the integrator for the first ISS loop engaged for more than a few minutes before the loop starts to oscillate.  But, with or without the integrator on, the diffracted power is moving around like crazy.

At this point, we are leaving the IFO in Down, and hopefully someone from Team PSL will come in and look at the ISS tomorrow, and then maybe locking will be possible.

As a side note, it appears that everything in the PSL is misaligned by a bit.  Both the PMC and RefCav transmissions are about 25% lower than normal, with corresponding increases in their reflected powers.  This is probably the reason that we've had to increase the FSS loop gain earlier today to make locking even the IMC possible (see Sheila's alog).

Evan G., Jeff K., Kiwamu I., Darkhan T.

Summary:
We have processed the DARM open loop gain and sensing function measurements and built a model of the loop that we believe sufficiently represents our knowledge of the parameters. In addition, the actuator coefficients have been remeasured using the Pcal. In summary, our model reproduces the DARM open loop transfer function to within +/-10% in magnitude and within +/-5 degrees in phase from 10 Hz to 1 kHz. Caveat: we have not yet assessed how this translates to the overall calibration uncertainty. Actuation coefficients for L1, L2, and L3 are within +/-5% of their O1 values. This model is used in the recently updated CAL-CS model (alog 28178).

Details:
The DARM measurements made recently (alog 28107) were processed using the updated DARM model code. Included in this new model is a functional form for the SRC detuning (alog 28150), and the fit to the measured data gives updated cavity gain, cavity pole frequency, time delay, and detuning spring frequency. The uncompensated OMC whitening filters are updated (alog 28087). Since the L1, L2, and L3 driver compensation has been updated (alogs 27150 and 27180), we removed all the measured and compensation zeros and poles, except for the uncompensated high frequency zeros and poles of the L3 stage (alog 27619). The AA/AI downsampling filters are using the RCG 3.0 64-16k filter coefficients (alog 27173).

Attached are figures showing (in order) the measurement and model comparison DARM open loop gain transfer function, the measurement and model comparison of the sensing function, and the L1/L2/L3 actuation coefficient measurements calibrated using the Pcal.

It was realized that since we no longer read out H1:CAL-DARM_ERR_WHITEN_OUT_DQ for the for the Pcal to DARM transfer functions--instead we are reading out H1:LSC-DARM1_IN1_DQ--the measurement to model comparison for the sensing function should not include the 1 16k clock cycle delay. However, the model for the sensing function should include this 1 16k clock cycle delay.

We tried a few different values for unknown sensing and actuation delays but did not attempt to optimize this any further.

There are 1 STS proof masses out of range ( > 2.0 [V] )!
STS EY DOF X/U = -2.072 [V]

(full results attached)

Evan G, Darkhan,

Summary

EPICS records that will be used by GDS pipeline for calculation of the DARM time-dependent parameters in ER9 were updated on 05-Jul-2016 17:44:57 PDT (06-Jul-2016 00:44:57 UTC).

Details

The H1 DARM model parameters used for generation of the EPICS values are

• IFO dependent param file: Runs/PreER9/Common/params/IFOindepParams.conf
• IFO dependent, H1, param file: Runs/PreER9/H1/params/H1params.conf
• Measurements param file: Runs/PreER9/H1/params/H1params_2016-07-01.conf

Output files: raw epics values, a verbose log and a Matlab file with EP# variables (see T1500377-08, Table 2) were committed to the calibration SVN directory (the verbose log is also attached to this alog):

Runs/PreER9/H1/Scripts/CAL_EPICS

./20160705_H1_CAL_EPICS_VALUES.txt
./20160705_H1_CAL_EPICS_verbose.log
./D20160705_H1_CAL_EPICS_VALUES.m
./callineParams_20160705.m
./writeH1_CAL_EPICS.m

Runs/O2/Common/Scripts/CAL_EPICS/writeO2_TDEP_EPICS.m

J. Kissel, E. Goetz, K. Izumi, D. Tuyenbayev

Evan will post the details of the work we've had to do to get the model running, but in the interest of time, I've taken what we needed from the Matlab model to update the CAL-CS front-end filters. Since early results indicate that the only low-frequency (sub-Nyquist) things that have changed from the O1 model are in the sensing function (see LHO aLOG 28171):
   - Lower optical gain = 9.071e5 [ct/m],
   - Lower frequency DARM coupled cavity pole frequency, f_c = 328.7 Hz, and
   - New SRC-detuned optical spring frequency, f_s = 9.831 Hz.
I only needed to update the H1:CAL-CS_DARM_ERR inverse sensing function filter (see further discussion below). 

The new settings have been captured in the SDF system.

Details of the design:
Foton Design String --
       zpk([9.831;-9.831;328.7],[0.1; 0.1;7000],1,"n")gain(9574.81)*gain(1.102e-6)
The gain of 1.102e-6 is 1 / 9.071e5 [ct/m], this lives separately in FM4, called "ER9gain." In FM3, in the filter called "SRC D-2N" for "Signal Recycling Cavity De-Two-Ne" there lies:
- The pair of real poles at 9.831 Hz, one of which is in the right-half-plane, reflect the detuning dynamics. Note that we've rolled of these inversion zeros at low frequency of two real poles 0.1 Hz. 
- The 328.7 Hz is the new f_c, and we retain the same high-frequency roll off of 7000 Hz.  
- The gain of gain(9574.81) which is the correct normalization gain to get the over-all gain to be unity at 100 Hz, which is the frequency at which I matched the no-detuning gain of the (unused) 329:7000 filter in FM3.
The attached PDF shows that the ER9 gains agree between detuning and no detuning, and as expected, the overall optical gain is ~20% lower that O1 because we've not yet digitally compensated for the ~20% lower optical gain (because of 20% lower PRC gain; see LHO aLOG 28133) in the DARM loop.


Further Discussion on why I've only updated the Sensing Function:
All actuation strengths are within ~5% of there O1 values (see LHO aLOG 28130), and we've compensated all electronics better (see LHO aLOGs 27180, 27150, and 28087), so we need not update anything in the actuation chain. Rana and Evan H. have changed the local, top-mass damping loop filters for the QUADs, so nominally the QUAD dynamics have been changed, but that should be a small effect in the GW band. We'll update for O2, but no need for ER9. There have been several changes to effects at high-frequency, but all of those are covered in the GDS FIR filters which absorb the CAL-CS output and acausaly correct for these super-Nyquist frequency effects.

Carlos, Jim

After installing Ubuntu 12 on h1tw0 and performing a file system check, the h1tw0 is now writing minute trend files.

4pm local

1/2 turn open on bypass LLCV - took 1:08 min. until LN2 came out the exhaust.

I noticed that the CW hardware injection excitation had stopped running at 15:47PDT Thursday 6/30. Using monit I have just restarted it.

State of H1: did not make it through Initial Alignment, Sheila and Jenne working on it

Activities:

listed in previous alog 28149

Since that alog:

• Dave and Jim  - End-X to fix CAL EX (ALS, PEM, CAL restart)
• Patrick - update VAC for new PID controller
• Joe - finished in the LVEA
• Nutsinee - finished with TCS sled and AOM drain
• Vinny and Carl back from EX
• JimW - restarting both end station SEI platforms
• DavidM - out of the LVEA
• JeffK - restarted ETM QUAD models
• Peter and Jason out of diode room
• Jenne and Chris - ITMs charge code
• Patrick and TJ - End stations to reset ESD high voltage
• Kyle - EY, energizing RGA WP#5979

Current Activities:  Jenne and Sheila out to LVEA to measure MC open loop gain

h1iscex lost timing

Jim, Dave:

at 09:41 PDT h1iscex lost its timing sync. Possibly due to a power cord being moved which drives the independent DC powered timing slave in the IO Chassis. Models were restarted at 11:50 PDT.

h1susetm and h1omcpi new models

Jeff, Carl, Dave

New h1susetm[x,y] and h1omcpi models were installed. DAQ was restarted

New Vacuum Controls code

Patrick, Dave

New Vacuum controls Beckhoff code was installed at all 7 locations. Required a DAQ restart.

alog tiny font fixed

an entry made this morning set the font size to x-small. This was fixed.

Ready to upgrade h1fw0 to 10 GigE if it becomes unstable WP5985

Jim, Dave

If h1fw0 becomes unstable, we will upgrade its CDS-LDAS link from 1GE to 10GE using borrowed LDAS cards. The next time it crashes it will not restart. We'll wait until 4pm PDT and then allow a restart.

The code on each Beckhoff vacuum controls computer has been updated to incorporate the new PI controller. All of the cryopumps are back on PID control. TJ and I turned back on the ESD high voltage at end X and end Y. Dave has updated the DAQ. This completes WP 5972.

After Patrick installed the new PID loop controller and rebooted, I set the smoothing factor on all cryopumps to 0.999.

Fil has hooked up the End Y Illuminator to a power supply temporarily until he can get the Beckhoff system back up to control it.  This was done at my request so our SURF students can continue working on the PCal Beam Localization project.

HWS

Ysled has been replaced. Below I attached a screenshot of the streamed images. The spare sled doesn't fit in the connector as well as the old one. The front part of the spare sled is slightly thicker. See pictures for details.

The dead sled number is 12.02.44 and the replaced spare is 07.14.264

CO2

Last week I disconnected TCS AOMs and the AOM drivers from water supplies but didn't have time to drain the hoses. Today I went in and finished the job. I left all the hoses on the tables except for one CO2Y AOM hose. The particulates wouldn't drain out and still stuck at the end of its quick connect. I don't think we ever want to plug that thing back in.

,

Here's what the table looks like now.

TCSX

TCSY

I also brought back a handful if particulate samples of anyone wants them.

This concluded WP#5977, WP#5978

As found, RGA was valved-in to Y-end -> Will take a few scans in an hour or so

With the measured sensing function (28123) in hand, we did an MCMC-based numerical fitting for the sensing function (see E. Hall, T1500553).

The fitting results are

• Optical gain = 8.980393e+05 +/- 7.965381e+02 [cnts/m]
• Cavity pole = 3.294194e+02 +/- 5.626792e-01 [Hz]
• Time delay = 1.973719e+02 +/- 3.386483e-01 [usec]
• Spring frequency = 9.825078e+00 +/- 5.453538e-02 [Hz]

[New sensing function form]

As reported by Evan (27675), it seems that the extra roll off in the DARM response at low frequencies are due to an SRC detuning (or something equivalent). While such detuning should be suppressed by some control loop ideally, we decided to include the detuning-induced functional form in addition to the ordinary single-pole response. We use the following approximated form for the DARM response

S(f) = H / (1 + i f / fc ) * exp( -2 * pi * f * tau) * f^2/(f^2 + fs^2)

where H, fc, tau and fs are the optical gain, DARM cavity pole, time delay and spring frequency. Some details of the derivation will be reported later. Apparently, we now have an additional quantity (i.e., fs) to fit.

Note that since H1 seems to be in (unintentionally) an anti-spring detuning, fs should be a real number whereas it should be an imaginary number for a pro-spring case. Obviously, Q is set to infinity for simplicity.

[MCMC-based numerical fitting]

Following the work by Evan (T1500553), we adapted his code to include the spring frequency as well. In short, it is a Bayesian analysis to obtain posteriors for the parameters that we want to estimate. We gave a simple set of priors as follows for this particular analysis.

• 0 < H < infinity
• 0 < fc < infinity
• 0 < tau < infinity
• 0 < fs  < infinity (real number)

The quad plot below shows the fitting result. The estimated parameters are obtained by taking the mean values of the resutling probability distribution. As usual, the two plots on the left hand side show a bode plot of the measured and fitted data. The two plots on the right hand side show the residual of the fit. As shown in the residuals, there are several points which are as big as 20% in magnitude and 6 deg in phase below 10 Hz. Otherwise, the residual data points seem to be within 10-ish % and 4 deg. The code is attached in pdf format.

EDIT: I am attaching the actual code as well.

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.