J. Kissel, D. Barker

As Darkhan caught last week (LHO aLOG 28126), when we installed the new individual stage oscillators on the QUADs (LHO aLOG 27733), we neglected to store the excitation channels in the frames. Today, I've added those channels to the ETM QUAD master model, stored inthe science frames at 512 Hz, and restarted the SUS. 

Channels:
H1:SUS-ETMY_LKIN_P_LO_DQ           512
H1:SUS-ETMX_L1_CAL_LINE_OUT_DQ     512
H1:SUS-ETMX_L2_CAL_LINE_OUT_DQ     512
H1:SUS-ETMX_L3_CAL_LINE_OUT_DQ     512
H1:SUS-ETMX_LKIN_P_LO_DQ           512
H1:SUS-ETMY_L1_CAL_LINE_OUT_DQ     512
H1:SUS-ETMY_L2_CAL_LINE_OUT_DQ     512
H1:SUS-ETMY_L3_CAL_LINE_OUT_DQ     512

Model Change to:
/opt/rtcds/userapps/release/sus/common/models/QUAD_MASTER.mdl

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

Took advantage of laser being down (aLOG #28142 & 28145) to change the water filters in the chiller room. 
Swapped out the Diode Chiller filter. The filter looked fine, but changed it out anyway to see if this had any effect on the rising PSL chiller pressures. 
Did not change the Chrystal Chiller filter. The filter bracket is poorly mounted to the wall and is coming loose. Need to secure the filter bracket to the wall before unscrewing the filter canister.         

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.

WP 5984--Addressing a couple month old bug, see SEI log 989 for details.  Summary: We had added a condition to turn off Damping if a platform trips but this code is common for HEPI and the ISI and the HEPI does not have a damping state so there was an error.  This was reverted and Friday Arnaud added a conditional to the code that excluded the HEPI from this action; it was tested at LLO.  I've updated the python code and restarted all the HPI nodes--no impact to the platforms.  See attached for keystrokes.  WP closed.

Diodes 3/4 are seemingly kaput.

Came in to find the laser was off due to the power watchdog being tripped.
Both chillers were still running.

I have turned the laser back on but it hasn't returned to where it normally
returns to.  Looking into what happened.

The beam position on the test masses is estimated from the a2l gains from the last minimization (method explained in alog 22426)

The gains values before and after the mimization are attached in a2l_gains_1151366417.mat.
The corresponding beam positions are reported in each suspension base in the Fig.1 attached. We can see that the beam is not more off-centered than previously.

However, we can observe that the beam hits the ITM and ETM in differents vertical places now in each cavity, suggesting an increase of the beam tilts in PIT with respect to the optical axes (HARD PIT).
That is what I tried to represent with the projection in Fig. 2, where you can imagine the cavities facing you: the figure axis orientation is the ETMs coordinates orientation.
The YAW tilts are reduced in both cavities. But their directions were opposite before the a2l minimization whereas now both cavity axes have a negative YAW tilt (in the ETM coordinates).

I don't know when the script was run for the last time before that, but it could give an indication that the beam is now more tilted in HARD PIT at 40W, and it enters the cavities from the lower area of the ITMs. 

Sheila, Jenne, Haocun

We took measurements on the C/DHARD yaw Loops with low bandwidth last Friday.

We firstly turned on the new filter to move compensation peaks for C/DHARD Yaw, then turn off the boost to win more phase. The gain was then lowered to ~half (CHARD_Y: -0.7 ---> -0.3, DHARD_Y: 40 ---> 19), and the new cutoff filters can be turned on.

These steps has been added in the Guardian, and we took measurements with the low noise loop, as attached below.

Both of the UGF are about 3.5Hz at 40 W now, which were ~5Hz before.

Engineering Run 9 (ER9) will begin next Wednesday. Here are some important details for operations:

• ER9 begins Wednesday July 6, 2016 8:00am PT, 15:00 UTC, 1151 852 417 GPS
  
• ER9 ends Friday July 8, 2016 23:59 PT, July 9, 2016 6:59 UTC, 1152 082 757 GPS
  
• Target input laser power: 40W operation. (This may be adjusted to deal with PI modes and to optimize observing time.)
• Only the H1 interferometer will be operational (a vent is on going at LLO)
• "Simulated" data for L1 and Virgo
• July 5th Maintenance:  A maintenance day will precede ER9 next Tuesday. Please consider the interferometer and its controls under a code freeze until after ER9.  Our focus is to have a stable,  running H1 for ER9.
• Plan for use of the calibration pipeline and DMT code running under SL7, with a fallback plan to run under SL6 if necessary.
• ER9 Daily Telecon:  Wednesday through Friday at noon PDT, 19:00 UTC, there will be ER9 Operational Status Telecons on the JRPC TeamSpeak channel.

Please see https://wiki.ligo.org/LSC/JRPComm/ER9 for more details.

Filled CP3 at ~ 1:50 UTC , 6:50 PM LOCAL Time Sunday.

Opened valve 1/2 turn and observed liquid after 5 minutes, 15 seconds. Windy on site.

Jeff K, Darkhan

Summary

Three DQ channels need to be added to the H1SUSETMY front-end model:

H1:SUS-ETMY_L1_CAL_LINE_OUT_DQ
H1:SUS-ETMY_L2_CAL_LINE_OUT_DQ
H1:SUS-ETMY_LKIN_P_LO_DQ

Details

SUSETMY model (both at H1 and L1) was updated to use synchronized oscillators to inject calibration lines into L1, L2 and L3 actuation stages to track temporal variations in the strengths of the drivers (LHO alog 27733). An additional calibration line is injected through Lock In oscillator (see attached screenshot 1).

In order to analyze time-dependent calibration of the drivers we need the excitation signals to be stored in the frames.

Hopefully, we will update the H1SUSETMY model on next Tuesday, Jul 5, 2016.

J. Kissel, J. Driggers, T. Shaffer, D. Tuyenbayev, E. Goetz, K. Izumi

Over two ~1-2 hour lock stretches, I've managed to get the measurements needed for a baseline calibration update for ER9. Complete success! We'll work on the data analysis tomorrow, but I list the locations where all measurements have been committed to the CAL repo below. 

Of particular notes for the configuration of the IFO while doing these measurements:
- The OMC DCPDs have *no* stages of whitening employed. We've decreed that given the unknown success rate of PI damping over the next few days, it's more robust to leave the whitening off. We're not gaining too much in the high frequency end of the sensitivity anyways.
- All suspensions, including ETMY, have had their PUM stage switched to "Acq ON, LP OFF," i.e. state 2, or the highest range (i.e. not low noise). After some digging, Jenne found this was changed for some reason about a month ago, and maybe a setting that got lost in the power outage or something. 
I don't think either of these seemingly detrimental configurations are all that bad for ER9, given the bigger sensitivity issues elsewere.

Also note, in order to break the correlations we've found in O1 data between measurements of Actuation Stage Strength (see e.g. LHO aLOG 28096), I've taken an independent PCAL2DARM sweep for every isolation stage.

Measurements needed for Sensing Function:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER9/H1/Measurements/PCAL/
2016-07-01_H1_PCAL2DARMTF_4to1200Hz_SRCTuned.xml
    Exported as:
    2016-07-01_PCALY2DARMTF_4to1200Hz_A_PCALRX_B_DARMIN1_coh.txt
    2016-07-01_PCALY2DARMTF_4to1200Hz_A_PCALRX_B_DARMIN1_tf.txt

/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER9/H1/Measurements/DARMOLGTFs/
2016-07-01_H1_DARM_OLGTF_4to1200Hz_SRCTuned.xml
    2016-07-01_H1_DARM_OLGTF_4to1200Hz_A_ETMYL3LOCKIN2_B_ETMYL3LOCKIN1_tf.txt
    2016-07-01_H1_DARM_OLGTF_4to1200Hz_A_ETMYL3LOCKIN2_B_ETMYL3LOCKIN1_coh.txt
    2016-07-01_H1_DARM_OLGTF_4to1200Hz_A_ETMYL3LOCKIN2_B_ETMYL3LOCKEXC_tf.txt
    2016-07-01_H1_DARM_OLGTF_4to1200Hz_A_ETMYL3LOCKIN2_B_ETMYL3LOCKEXC_coh.txt


Measurements needed for Actuation Function:
/ligo/svncommon/CalSVN/aligocalibration/trunk/Runs/PreER9/H1/Measurements/FullIFOActuatorTFs/
2016-07-01_PCALYtoDARM_FullLock_L1.xml
    2016-07-01_H1SUSETMY_PCALYtoDARM_ForL1Drive_FullLock_tf.txt
    2016-07-01_H1SUSETMY_PCALYtoDARM_ForL1Drive_FullLock_coh.txt

2016-07-01_H1SUSETMY_L1toDARM_FullLock.xml
    2016-07-01_H1SUSETMY_L1toDARM_State1_FullLock_tf.txt
    2016-07-01_H1SUSETMY_L1toDARM_State1_FullLock_coh.txt


2016-07-01_PCALYtoDARM_FullLock_L2.xml
    2016-07-01_H1SUSETMY_PCALYtoDARM_ForL2Drive_FullLock_tf.txt
    2016-07-01_H1SUSETMY_PCALYtoDARM_ForL2Drive_FullLock_coh.txt

2016-07-01_H1SUSETMY_L2toDARM_FullLock.xml
    2016-07-01_H1SUSETMY_L2toDARM_State2_FullLock_tf.txt
    2016-07-01_H1SUSETMY_L2toDARM_State2_FullLock_coh.txt


2016-07-01_PCALYtoDARM_FullLock_L3.xml
    2016-07-01_H1SUSETMY_PCALYtoDARM_ForL3Drive_FullLock_tf.txt
    2016-07-01_H1SUSETMY_PCALYtoDARM_ForL3Drive_FullLock_coh.txt

2016-07-01_H1SUSETMY_L3toDARM_LVLN_LPON_FullLock.xml
    2016-07-01_H1SUSETMY_L3toDARM_LVLN_LPON_FullLock_tf.txt
    2016-07-01_H1SUSETMY_L3toDARM_LVLN_LPON_FullLock_coh.txt

Between yesterday and today, Gerardo and I successfully bonded the ears to core optic mass ETM15, destined for LLO for post-O1 eventual replacement. 

Ear s/n 195 bonded to S3 flat of mass June 29, 2016

Ear s/n 196 bonded to S4 flat of mass June 30, 2016

The first ear (s/n 195) has a series of bubbles along it's edge, but the surface area of these do not add up to more than the allowed amount as per E1000277, so it passes, see pix attached.

The second ear (s/n 196) has no bubbles and is nice full bond.