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  2466   Fri Oct 25 16:50:12 2019 anchalNotesPMCSouth PMC problem debugging effortsToday, this problem happened again (check
history for details). I have done the following
investigative steps:
  2465   Thu Oct 24 11:42:06 2019 Ian MacMillanNotesFSSFSS Plant Model v2With discussions with Anchal and some reading

It seems impossible to create a
casual circuit with a zero phase shift. (See
  2464   Wed Oct 23 17:39:44 2019 anchalNotesPMCSouth PMC started working somehow :(The same thing happened again. This time,
not just with the SPMC actuation voltage,
but the South Laser slow voltage control
  2463   Wed Oct 23 13:21:12 2019 anchalDailyProgressNoiseBudgetFixed all discrepancies.I ran the code for aLIGO coating structure
and tried to reproduce fig5 and fig7 of Hong
  2462   Tue Oct 22 13:07:45 2019 Ian MacMillanNotesFSSFSS Plant Model v2I have designed a passive circuit that
seems to match the ideal transfer functions
in shape. Scaling should just be a game of
  2461   Fri Oct 18 17:47:49 2019 anchalNotesBEATQuick note: BN Noise bakc to where it was.Latest BN
Spectrum: CTN_Latest_BN_Spec.pdf

  2460   Wed Oct 16 19:11:11 2019 anchalNotesBEATQuick note: Cavities locked; Changed BN Freq Counter Poll Rate
Follow discussion in thread 
polling rate of beatnote frequency counter
  2458   Wed Oct 16 18:46:58 2019 anchalNotesPMCSouth PMC started working somehow :(Yeah, the cables are isolated and no inversion
could happen.

  2457   Wed Oct 16 17:33:08 2019 KojiNotesPMCSouth PMC won't work with it's own Servo Card onlyAre you sure that all the cables involved
are isolated and there is no polarity inversion?
e.g. The unfunctional combination provides
  2456   Wed Oct 16 16:56:43 2019 anchalNotesPMCSouth PMC won't work with it's own Servo Card onlyI have a wierd observation. The following
two combination work:

  2455   Tue Oct 15 18:54:16 2019 anchalNotesPMCSouth PMC further problemsWith Laser actuation not connected, I see
that the South PMC Servo board is acting
up. Firstly, it is not responding to changes
  2454   Tue Oct 15 18:53:00 2019 anchalNotesSafetyQuick note: Lasers started againI have taken the bulb from ATF lab inside
sign for now. I'm ordering a new one
to replace that soon.
  2453   Tue Oct 15 13:23:16 2019 anchalNotesSafetyQuick note: Shutting Down Lasers as Safety Sign is not workingFollowing up after CTN:2452,
the laser safety sign is not working. Hence
the lab has been shut down now. All lasers
  2452   Mon Oct 14 18:30:14 2019 anchalNotesPMCSouth PMC Error Signal OscillationsSouth PMC Error signal is showing huge
weird capacitor charging type oscillations.
Attached is an oscilloscope measurement of
  2451   Mon Oct 14 17:01:43 2019 anchalNotesLaserSouth Laser Switched Off!On Oct 11th at 15:04:04, the south laser
switched off on its own. I would like to
know if anyone entered the lab around this
  2450   Mon Oct 14 12:54:41 2019 anchalNotesFSSFSS Plant Model v2I have updated the plant model to contain
the cavity pole also. Cavity pole is a pair
of positive and negative real poles, so it
  2449   Wed Oct 9 16:08:39 2019 anchalDailyProgressBEATBeatnote Frequency long time series dataWhoever commented last, suggested a good
idea. So I've here plotted the NPRO slow
control voltage signals, converted into the
  2448   Tue Oct 8 16:48:07 2019 putInYourRealNameDailyProgressBEATBeatnote Frequency long time series datacomment on goodness of Temperature controls:

Since the frequency is wandering
by ~3 kHz at the hours time scales, we can
  2447   Tue Oct 8 10:41:43 2019 anchalNotesFSSFSS Plant ModelThe nodes at input and output of buffer
in the PZT path are connected together. That
is wrong. Also, If possible, you should name
  2446   Fri Oct 4 14:56:42 2019 Ian MacMillanNotesFSSFSS Plant ModelSchematic of Plant Model

  2444   Fri Oct 4 13:41:44 2019 anchalNotesFSSFSS Plant ModelI and Ian discussed what the transfer functions
would look like. Then today, using some old
calculations, I put up this notebook which
  2443   Wed Oct 2 19:09:31 2019 anchalDailyProgressFSSTTFSS OLTFs; Repeated this 5 year old measurementI repeated the measurement done by Tara
and Evan to update residual NPRO noise in
our noise budget.
  2442   Wed Oct 2 15:13:27 2019 anchalDailyProgressNoiseBudgetChecking variation in estimated Coating Brownian Noise with Beam RadiusI updated this calculation by adding curves
for contribution through bulk loss angle
and shear loss angle separately. Rana suspected
  2441   Wed Oct 2 12:22:44 2019 anchalDailyProgressBEATBeatnote Frequency long time series dataAfter the new PID parameters were tuned
I waited for some time and the beatnote was
  2440   Tue Oct 1 17:28:25 2019 anchalNotesBEATQuick note: Moku connected with USBLiquid Instrument's Application Engineer
at La Jolla told me that connection with
moku might be mroe stable if it is directly
  2439   Tue Oct 1 13:46:49 2019 anchalDailyProgressNoiseBudgetUsing bayesian inference to estimate loss AnglesI used the method described in Section
V of https://arxiv.org/abs/1406.4467,
to do a bayesian inference using mechanical
  2438   Mon Sep 30 20:08:42 2019 anchalDailyProgressNoiseBudgetChecking variation in estimated Coating Brownian Noise with Beam RadiusVariation of the estimate of coating Brownian
noise as beam spot radius on the mirror changes.
Plotted in displacement noise as the frequency
  2437   Mon Sep 30 16:47:15 2019 anchalDailyProgressNoiseBudgetAdding links again; Comparison with Old Estimates on same plotWith comparison with old estimates:

  2436   Mon Sep 30 12:25:24 2019 ranaDailyProgressNoiseBudgetChecking variation in estimated Coating Brownian Noise with Loss Angles 2D Plotsbut then we lost the comparison with the
old calculation somehow...
  2435   Mon Sep 30 11:14:41 2019 anchalDailyProgressNoiseBudgetChecking variation in estimated Coating Brownian Noise with Loss Angles 2D Plots2D Heat Maps

Edit: Added comparison plot as
  2434   Fri Sep 27 16:40:49 2019 anchalDailyProgressNoiseBudgetChecking variation in estimated Coating Brownian Noise with Loss Angles Better PlotsBetter Plots attached.  VariationOfCoatingBrownianNoiseEstimate.pdfVariationOfCoatingBrownianNoiseEstimate.zip 
  2433   Tue Sep 24 19:39:06 2019 anchalDailyProgressNoiseBudgetChecking variation in estimated Coating Brownian Noise with Loss AnglesGabriele suggested that I plot the estimated
coating Brownian noise for different values
of bulk and shear loss angles and compare
  2432   Tue Sep 24 17:11:13 2019 anchalDailyProgressNoiseBudgetAdding specifics of discepancy 2 (More)Also, I found that the effective reflectivities
from the top surface of layers calculated
in Evans
  2431   Tue Sep 24 15:40:33 2019 anchalDailyProgressNoiseBudgetAdding specifics of discepancy 2Today I ran the two codes with the same
parameter values to check if the effective
reflectivities calculated during the calculation
  2430   Fri Sep 20 18:34:19 2019 anchalNotesVacuumPossible reflected lights on upgradeAttached is a first attempt at tracing
the rays on reflection from the wedged and
tilted window together with the cavity mirror.
  2429   Mon Sep 16 18:03:33 2019 anchalNotesBEATQuick note: Detector changed to Sn101
Beatnote is stabalized to 27.3
MHz. Changing detector to SN101.
South PMC Variable Gain to -2dB from -1dB
  2428   Mon Sep 16 17:05:00 2019 anchalSummaryBEATBeatnote Frequency stabalizationOver the weekend, I ran Relay Tuning method
for the PID of beatnote frequency control.
After CTN:2426 this
  2427   Fri Sep 13 16:59:39 2019 anchalDailyProgressPMCSouth PMC Servo Card changesGain was way too low

header H1 was not shorted on the board.
reduced the gain of first stage to only 2,
  2426   Fri Sep 13 16:46:54 2019 anchalSummaryTempCtrlCavity heater resistances remeasuredPresent understanding

was the last measurement of cavity shield
  2425   Fri Sep 13 16:40:56 2019 anchalDailyProgressBEATNew channel added; BNSignUpdate made better
as a new channel. This holds the seconds
derivative of precavtybeatnote frequency
  2424   Wed Sep 11 10:42:50 2019 anchalDailyProgressNoiseBudget500 Hz hump gone!

Checkout the latest noisebudget.
  2423   Tue Sep 10 20:03:02 2019 anchalDailyProgressNoiseBudgetLoss angle value updated again.As presented in LIGO-G1901676 and   ComparisonOfUsingDifferentLossAngles2.pdf 
  2422   Tue Sep 10 19:43:02 2019 anchalNotesBEATQuick note: Detector changed to NF1811
Changed detector to NF1811
in NPMC servo card. See CTN:2421.
noise budget with new bulk loss angle estimates
  2421   Tue Sep 10 17:13:51 2019 anchalDailyProgressPMCNorth PMC Servo Card UpgradedIt turns out that the noise is either injected
through the EOMs or through some mechanical
oscillation in the table or through RFPD
  2420   Mon Sep 9 16:31:34 2019 anchalDailyProgressPMCNorth PMC open loop investigationI opened the NPMC servo box and ran TF analysis
up to all test points and compared with their
zero model. Everything looks normal in these
  2419   Fri Sep 6 11:51:17 2019 awadeSummaryTempCtrlSummary of parameters and dimensions for thermal modelingThere's an error here. The factor of
2 should not be there. Correct equation would
  2418   Thu Sep 5 19:52:06 2019 anchalNotesBEATQuick note: FSS gain reduced, Moku input range changed
Changed North FSS Fast gain back
to 10 dB.
Increased threshold for
gain cycling to 0.1 on both FSS paths. This
  2417   Thu Sep 5 19:32:02 2019 anchalDailyProgressPMCNorth PMC might be cause of 500Hz bumpI was looking at the error signals of PMC
servo and found some systematic oscillations
in NPMC error signal at around 500 Hz.
  2416   Thu Sep 5 16:59:36 2019 anchalDailyProgressBEATBeatnote Frequency long time series dataAttached is captured beatnote frequency
between Aug 27th 2019 to Today, Sep 5th 2019.

I have attached a few more zoomed-in
  2415   Thu Sep 5 11:15:06 2019 anchalDailyProgressTempCtrlVacuum Can Temperature Control Setpoint Step Test - ResultsI used the calibration of North and South
NPRO control voltage to frequency change
from CTN:1948.
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