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

J. Kissel

I've completed the weekly charge measurements; results attached below. I've also flipped the ETMX and ETMY bias signs, as per our plan for testing if ISC and CAL can handle the collateral damage of mitigating charge in this fashion. For now, I've only flipped the bias, and am waiting to see if what we coded in to guardian two weeks ago (see LHO aLOG 27890) will take care of the rest of the settings changes that account for that flip.

Just for clarities sake, since I *know* where gunna start losing track of which direction the bias was flipped -- today the biases were flipped as follows:
    ETMX from -9.5 [V] to +9.5 [V]
    ETMY from +9.5 [V] to -9.5 [V]

Though we had originally intended to flip the bias signs every week, last week's maintenance was far too hectic so Betsy was only able to get charge measurements at the last minute on Wednesday (see LHO aLOG 28093), and Thursday was too hectic with calibration measurements (and the IFO was already locked when I remembered) that we forgot to flip the bias sign. So, we flip this week on schedule.

As we have found when we'd done rapid flipping last summer, the charging rate after a sign flip is unpredictable. For example, though it's difficult to quantify with only two data points, between the last flip and today the charging rate is rather fast on ETMX (5 [V / week] as opposed to 2.5 [V / week] prior to the last flip). This is the sort of thing we need to keep an eye on, lest we again forget for a week, or the apparently-random-walking of charging rate starts, on average, bringing us to accumulate charge of a particular sign. This might also indicate that flipping the bias sign every two weeks (instead of every week) is better, given our frequency of charge measurements and the need to have several before establishing a trend. 

As per alog entry 28145 a pair of diodes in the
front end laser were MIA this morning.  Suspect it was due to a faulty Beckhoff terminal as this terminal did not light up
with the front end diode box on.  We replaced the front end diode box and the corresponding module does light up.

    The SMA fibre connectors were all tweaked to maximise the diode power.  The fibre connectors were examined with an
infrared camera, typical temperatures were about 25-26 degC.

    The laser is up and running.  Should be okay for the engineering run.  We will need to tweak things after the run
however.




  Jason, Peter

Chris Whittle, Jenne, Jeff K

Wanted to test methods of measuring ITM charge.  We didn't have DARM to check, but the code for length drive charge measurements seems to work. This code (/ligo/svncommon/SusSVN/sus/trunk/QUAD/Common/Scripts/ESD_ITM_charge_measurement.py) measures the DARM response at various bias voltages and finds the TM charge as the zero crossing.

We tried driving the ITMY ESD to see if we could do the same optical lever charge measurements as the ETM. We tried turning off UL and LL to get a yaw drive. Changing the voltage bias on the test mass resulted in no change in phase in the optical lever (as would have been expected). We also tried a pitch drive and single quadrant drive and saw the same lack of phase change. We need to confirm the mappings for the ESD quadrant switches. The SUS overview screen was inconsistent with the binary I/O screen. We also need to make sure that the analog switches are actually switching.

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.

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.