Displaying reports 56141-56160 of 83536.Go to page Start 2804 2805 2806 2807 2808 2809 2810 2811 2812 End
Reports until 14:14, Tuesday 05 July 2016
H1 TCS (AOS)
nutsinee.kijbunchoo@LIGO.ORG - posted 14:14, Tuesday 05 July 2016 (28162)
TCS Maintenance -- All done

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

Images attached to this report
H1 SUS (CAL, ISC)
jeffrey.kissel@LIGO.ORG - posted 13:49, Tuesday 05 July 2016 (28152)
Charge Measurement Update; Weekly Charge Measurement Complete and Bias Sign Flipped on ETMX and ETMY
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. 
Images attached to this report
H1 PSL (PSL)
peter.king@LIGO.ORG - posted 13:47, Tuesday 05 July 2016 - last comment - 13:59, Tuesday 05 July 2016(28160)
Front end laser epilogue
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
Comments related to this report
peter.king@LIGO.ORG - 13:59, Tuesday 05 July 2016 (28163)
I forgot to mention that the relock counter for the injection locking was reset in Beckhoff.
Currently reads at 1.

Front end operating hours currently reads 32319 hours, even though the front end diode box
is new.
H1 SUS (SUS)
chris.whittle@LIGO.ORG - posted 13:44, Tuesday 05 July 2016 (28161)
Testing ITM charge measurement code and optical levers
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.
H1 CAL (SUS)
jeffrey.kissel@LIGO.ORG - posted 13:17, Tuesday 05 July 2016 (28156)
New (and Old) SUS Oscillator Excitation Signals Added to Frames
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
LHO VE
kyle.ryan@LIGO.ORG - posted 13:05, Tuesday 05 July 2016 - last comment - 16:15, Tuesday 05 July 2016(28155)
1240 hrs. local -> Connected electronics and energized Y-end RGA filament
As found, RGA was valved-in to Y-end -> Will take a few scans in an hour or so
Comments related to this report
kyle.ryan@LIGO.ORG - 16:15, Tuesday 05 July 2016 (28172)
I am short pwr supplies for the electronics so I had to de-energize the filamnet, i.e. leaving the configuration as found.
H1 PSL
jeffrey.bartlett@LIGO.ORG - posted 12:25, Tuesday 05 July 2016 - last comment - 08:04, Thursday 07 July 2016(28154)
Change Diode Chiller Filter (WP #5983)
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.         
Comments related to this report
jeffrey.bartlett@LIGO.ORG - 08:04, Thursday 07 July 2016 (28221)
  48 hours after changing the Diode filter the PSL chiller pressures and flows seem to be flattening out. Will continue to monitor over the next several days. The plan is to swap out the Crystal chiller filter in conjunction with remounting the filter housing.   
Images attached to this comment
H1 CAL
kiwamu.izumi@LIGO.ORG - posted 11:36, Tuesday 05 July 2016 - last comment - 14:16, Friday 08 July 2016(28150)
Fit of sensing function completed

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


[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.

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.

Images attached to this report
Non-image files attached to this report
Comments related to this report
kiwamu.izumi@LIGO.ORG - 15:15, Tuesday 05 July 2016 (28170)

A detailed derivation of the new functional form can be found at https://dcc.ligo.org/LIGO-T1600278

kiwamu.izumi@LIGO.ORG - 16:03, Tuesday 05 July 2016 (28171)

EvanG noticed that we have unintentionally included high frequency poles in the previous analysis (28157). So we made the same fitting for the data with all the high frequency poles removed.

Here are the fitting results for the latest data:

  • Optical gain = 9.070764e+05 +/- 8.071988e+02 [cnts/m]
  • Cavity pole = 3.287361e+02 +/- 5.692504e-01 [Hz]
  • Time delay = 5.554816e+00 +/- 3.424867e-01 [usec]
  • Spring frequency = 9.831483e+00 +/- 5.434934e-02 [Hz]

Since the bode plot looks very similar to the one posted above, I skip showing it here. Observe that the time delay is now smaller than it was because we now don't have the high frequency poles.

craig.cahillane@LIGO.ORG - 14:16, Friday 08 July 2016 (28274)CAL
C. Cahillane, K. Izumi

I have added in a new term to our sensing function fit, an optical spring Q factor to gain back phase information.

From the functional form f^2/(f^2 + f_s^2) we only get a magnitude correction from detuning, but we also expect detuning to slightly affect phase in the sensing function response.

This can be clearly seen in lower right subplot Figure 1 of this comment, where Kiwamu originally plotted the full RSE sensing function.  Here we see that when we have 1 degree of detuning we also have +1.5 degree phase difference at 10 Hz when compared to the sensing function without detuning. 

In the phase residual plot in the original post you can see this phase loss in the actual ER9 sensing measurement.  

In order to try and gain back some of this phase information, we have added in an additional term to the detuning function:

    f^2                        f^2
-----------    ===>  -----------------------
f^2 + f_s^2          f^2 + f_s^2 - i*f*f_s/Q

This adds another parameter to our fit, but lets us get back phase information lost to detuning.

**********

Figure 2 shows Kiwamu's original fit parameters posted above in red alongside my new results in green.
I argue that including the optical spring Q factor has improved the phase fit significantly.  
Quantitatively, here are the phase Χ-Square values:

With Optical Spring Q Χ-Square    = 85.104
Without Optical Spring Q Χ-Square = 819.28

**********

I have modified Kiwamu's SensingFunction.ipynb into a SensingFunctionSimulation.ipynb which fits to both phase and magnitude of the sensing function.  SensingFunctionSimulation.ipynb is attached as a zipped file in this aLOG and is also in a Git repo called RadiationPressureDARM owned by Kiwamu.

Fit parameters:

Optical gain = 9.124805e+05 +/- 8.152381e+02 [cnts/m]
Cavity pole = 3.234361e+02 +/- 5.545748e-01 [Hz]
Time delay = 5.460838e+00 +/- 3.475198e-01 [usec]
Spring frequency = 9.975837e+00 +/- 5.477828e-02 [Hz]
Spring Inverse Q = 1.369124e-01 +/- 3.522990e-03

(I choose to parametrize using inverse Q = Q^{-1} because Q^{-1} can be zero.)
Images attached to this comment
Non-image files attached to this comment
H1 SEI (GRD)
hugh.radkins@LIGO.ORG - posted 11:18, Tuesday 05 July 2016 - last comment - 13:32, Tuesday 05 July 2016(28151)
LHO HEPI Guardians Restarted w/corrected code

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.

Images attached to this report
Comments related to this report
hugh.radkins@LIGO.ORG - 13:32, Tuesday 05 July 2016 (28159)

Duh, of course since the code is common, I actually need to restart all the SEI and ISI guardians as well.  This has been done and the platforms were not affected--thanks guardian programmers!  And thanks to Arnaud for pointing this out to me.  The txt file attached has the restart record.

Non-image files attached to this comment
H1 General (OpsInfo)
cheryl.vorvick@LIGO.ORG - posted 10:02, Tuesday 05 July 2016 - last comment - 11:26, Tuesday 05 July 2016(28149)
Maintenance as of 9:24PT, 16:24UTC - laser is down
microphones Vincent calibration
LVEA Joe batteries
CR Dale tours at noon
all buildings Christina-Karen cleaning
all buildings Fil electorinics inventory
all buildings Joe-Sprague spraying
LVEA Kyle energizing turbo pumps
all buildings Huge checking HEPI pumps
EX and EY JeffK charge measurements
EX and EY Kyle energise RGA filaments
laser Peter-Jason take PSL offline
LVEA DavidM physical measurements
LVEA Nutsinee

swap TCS sled and drain AOM

Comments related to this report
cheryl.vorvick@LIGO.ORG - 11:26, Tuesday 05 July 2016 (28153)

Since last alog:

  • EX-EY - Vincent - microphone-calibration
  • LVEA - Fil - electronicsInv
  • all platforms - Huge - modify HEPI guardians
  • LVEA - Christina/Karen - cleaning
  • Ex-EY - JeffK - EX/EY model restart
  • all buildings - pest control is complete, they checked in as they left

Current:

in LVEA:

  • Nutsinee, TCS
  • Christna, cleaning
  • Fil, inventory
  • David McManus, physical measurements

In end stations:

  • Vincent, microphone calibrations

coming up:

  • DAQ restart
  • small tour to LVEA around 11:30
  • large tour of children at noon
  • restarting laser, H1 recovery
H1 General
cheryl.vorvick@LIGO.ORG - posted 09:18, Tuesday 05 July 2016 (28146)
Morning update: Maintenance is underway - light pipe from LVEA being closed for work on TCS table
H1 PSL
peter.king@LIGO.ORG - posted 09:15, Tuesday 05 July 2016 - last comment - 09:55, Tuesday 05 July 2016(28145)
Front end laser is hobbled
Diodes 3/4 are seemingly kaput.
Comments related to this report
jason.oberling@LIGO.ORG - 09:55, Tuesday 05 July 2016 (28147)

Filed FRS 5822.

H1 PSL (PSL)
peter.king@LIGO.ORG - posted 07:09, Tuesday 05 July 2016 - last comment - 09:11, Tuesday 05 July 2016(28142)
Laser down
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.
Comments related to this report
peter.king@LIGO.ORG - 07:12, Tuesday 05 July 2016 (28143)
The laser tripped around 4:15 this morning.
peter.king@LIGO.ORG - 09:11, Tuesday 05 July 2016 (28144)
Looks like the NPRO tripped out.  Maybe due to a minor power surge due to the start of the
week?

    Pre-modecleaner had some problems locking irrespective of the reference level.  Found
that a small tweak to the horizontal alignment brought things back right away.

    Note in passing: with no light the output of the locking photodiode was ~ +29 mV.
Unlocked (ie with light incident on the pre-modecleaner) the output was ~ -230 mV.
Which is sort of low, which might be consistent with a small mis-alignment.  The
locking photodiode is a 1 mm InGaAs photodiode after all.
H1 CAL (CAL)
darkhan.tuyenbayev@LIGO.ORG - posted 16:01, Friday 01 July 2016 - last comment - 13:18, Tuesday 05 July 2016(28126)
DQ channels need to be added to the SUS ETMY model to track new calibration lines

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.

Images attached to this report
Comments related to this report
gregory.mendell@LIGO.ORG - 17:50, Friday 01 July 2016 (28131)

Darkhan suggests these are the channels to use:


TST / L3                 35.3              0.11       H1:SUS-ETMY_LKIN_P_LO_DQ
PUM / L2                 34.7              1.1        H1:SUS-ETMY_L2_CAL_LINE_OUT_DQ
UIM / L1                 33.7              11.0       H1:SUS-ETMY_L1_CAL_LINE_OUT_DQ

With his help, for the pcalmon SLM pipeline  looking at these "new" frequencies here,

https://ldas-jobs.ligo-wa.caltech.edu/~gmendell/pcalmon_new_freqs/daily-pcalmonNavigation.html

the configuration is now set to:


set channelFrequencyList {H1_R,H1:SUS-ETMY_LKIN_P_LO_DQ,35.3aup;H1_R,H1:SUS-ETMY_L2_CAL_LINE_OUT_DQ,34.7aup;H1_R,H1:SUS-ETMY_L1_CAL_LINE_OUT_DQ,33.7aup;H1_R,H1:CAL-PCALY_EXC_SUM_DQ,35.3aup,34.7aup,33.7aup,331.9aup;H1_R,H1:CAL-DARM_ERR_WHITEN_OUT_DBL_DQ,35.3aup,34.7aup,33.7aup,331.9aup;H1_R,H1:CAL-DARM_CTRL_WHITEN_OUT_DBL_DQ,35.3aup,34.7aup,33.7aup,331.9aup;H1_R,H1:CAL-PCALY_TX_PD_OUT_DQ,35.3aup,34.7aup,33.7aup,331.9aup;H1_R,H1:CAL-PCALY_RX_PD_OUT_DQ,35.3aup,34.7aup,33.7aup,331.9aup;H1_R,H1:CAL-DELTAL_EXTERNAL_DQ,35.3aup,34.7aup,33.7aup,331.9aup;H1_HOFT_C00,H1:GDS-CALIB_STRAIN,35.3aup,34.7aup,33.7aup,331.9aup}

I've regenerated the SLM data for July 1.  The suggested channels above do not yet exist, and SLM will put 0's in for these until they do.

 

jeffrey.kissel@LIGO.ORG - 13:18, Tuesday 05 July 2016 (28158)
These new channels has now been added to the frames. See LHO aLOG 28156
H1 CAL
jeffrey.kissel@LIGO.ORG - posted 22:11, Thursday 30 June 2016 - last comment - 13:18, Tuesday 05 July 2016(28107)
Baseline Calibration Measurements for ER9 Complete!
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
Comments related to this report
jeffrey.kissel@LIGO.ORG - 15:53, Friday 01 July 2016 (28123)
J. Kissel, E. Goetz

Just to post a status report before I disappear for the 4th, Evan and I have used Evan's new infrastructure to produce a model of the DARM open loop gain and sensing function from the above measurement. As one can see, there's still some work to do cleaning up the systematics in the model, but we're close. 

There're several things that are immediately evident:
- We have not changed the model's optical gain value from O1, so it's not terribly surprising that the optical gain model is high by 20%. 
- There is total and obvious detuning. So much so, that I think this is what's causing the severe drop in open loop gain.
- The drop in open loop gain is pretty nasty -- it causes sharp gain peaking at 10 Hz (as shown by the screenshot of the DTT template).

Kiwamu's working on a fitting routine that is similar to Evan's MCMC results from O1 (see T1500553), but advancing those results to include the effects of detuning so that we can add this to the model.

Stay tuned! Lots of work to do before Wednesday!
Images attached to this comment
Non-image files attached to this comment
evan.goetz@LIGO.ORG - 17:19, Friday 01 July 2016 (28130)

Evan G., Jeff K.

I processed the suspension actuation coefficients for the L1, L2, and L3 stages using the preliminary DARM model based on the one used during O1. We know that there need to be some modifications made, but the take home message here is that the actuation coefficients are about as to be expected. All are within ~5% of their O1 values. See attached figures.

The first attachment shows the UIM stage actuation coefficient. We have not yet included the BOSEM inductance and we have not yet included any actuator dynamics, so there is remaining discrepancy above ~20 Hz. There also appears to be some sort of phase wrapping issue that we still need to sort out.

The second attachment shows the PUM stage actuation coefficient. Things look pretty good here, although there may be some fluctuating optical gain which we have not yet accounted for in the measurement.

The third attachment shows the TST stage actuation coefficient. Again, there may be some fluctuating optical gain not accounted for in the measurement, and there is a phase wrapping issue to be sorted out.


Next on the agenda is to sort out the above issues and establish the actuation coefficients for the ER9 run.
 

Non-image files attached to this comment
evan.goetz@LIGO.ORG - 13:18, Tuesday 05 July 2016 (28157)

The sensing function attached above includes uncompensated high frequency poles from the whitening chassis and the transimpedence amplifier, so there will be some delay assocated with these values.

To see only the optical response, we have removed these high frequency poles, as well as the analog AA and digital AA transfer functions, in the attached data file.

Non-image files attached to this comment
H1 SUS
betsy.weaver@LIGO.ORG - posted 15:59, Thursday 30 June 2016 - last comment - 14:46, Wednesday 04 April 2018(28090)
ETM15 Ears bonded

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. 

Images attached to this report
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betsy.weaver@LIGO.ORG - 11:54, Friday 01 July 2016 (28118)

Inspection of the bonds this morning showed no change to the nice S4/Ear surface bond.

The small edge bubbles along the S3 Ear have migrated a bit (not worse, just moved a bit).  Therefore, we decided to rewet the edge with solution to see if it would wick in and close some of the bubbles.  This worked to close one of the larger bubbles, but one bubble continued to morph so we'll reinspect Monday.  Note, none of the sizes of the bubbles got bigger, so the surface area of the bubble total remains the same and below spec.

Images attached to this comment
betsy.weaver@LIGO.ORG - 10:02, Tuesday 05 July 2016 (28148)

Attached is a picture of what the bubbles in the ETM15 S3 Ear bond look like today (recall, it was bonded last Wed so it has now been over 5 days since initial bond).  Apparently over the weekend, the bubbles ran inbound a bit further.  I estimate the surface are of the bubbles to be near 20mm sq., still under the 50mm sq. spec. E1000278, although it isn't pretty.  I measured the longest streaks to be almost 3mm long, with a width of 0.4mm.  There are no bubbles inward from the edge near the center - anything shown in the picture is a camera reflection.

 

The S4 Ear bond looks unchanged from inspection last week, very good bond, very little bubbles.

Images attached to this comment
betsy.weaver@LIGO.ORG - 14:46, Wednesday 04 April 2018 (41291)

Pictures of this ear bond taken by Danny at LLO just before use at LLO, indicate that the bubbles have not changed shape or size since the picture attached July 2016.  Phew, said both Gerardo and I.

Images attached to this comment
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