40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  PSL  Not logged in ELOG logo
Entry  Sun Nov 12 22:34:50 2017, Craig, awade, DailyProgress, NoiseBudget, Nov 12 Noisebudget PLL_OLG_SR785_Math_FMDevn_1kHz_PreampGain_2000_12-11-2017_195046_TF.pdfPLL_OLG_SR785_Math_FMDevn_1kHz_PreampGain_2000_12-11-2017_195046.tgz20171113_102854noiseBudget.pdf
    Reply  Mon Nov 13 15:45:19 2017, Craig, awade, HowTo, NoiseBudget, Nov 12 Noisebudget revised 20171113_151130noiseBudget.pdfPLLControlSignalSpectrum_Avg_30_FMDevn_1kHz_PreampGain_2000_Span_102p4kHz_12-11-2017_211211_Spectrum.pdf
       Reply  Mon Nov 13 18:06:32 2017, awade, Craig, DailyProgress, Schedule, Task list Nov 13, 2017 NorthLowerPeriscopeMirror_2017-11-13_16.48.15.jpgSouthLowerPeriscopeMirror_2017-11-13_16.49.35.jpg
          Reply  Mon Nov 13 21:53:25 2017, rana, DailyProgress, Schedule, Task list Nov 13, 2017 
Message ID: 1978     Entry time: Sun Nov 12 22:34:50 2017     Reply to this: 1979
Author: Craig, awade 
Type: DailyProgress 
Category: NoiseBudget 
Subject: Nov 12 Noisebudget 

The lastest noisebudget is attached.  Here is the online Bokeh version.

We are reaching the levels that Evan and Tara reached in a small frequency region around 1 kHz.  We are supposed to do about 10 times better than them to reach the coating brownian noise floor for the AlGaAs coatings.

We took the PLL OLG via the SR785, as well as the transmission beatnote spectra.  I divided every spectrum by two because of the impedence matching effect.

The PLL was locked at 1 kHz/Vrms frequency modulation, and SR560 preamp gain of 2000.  This led to the PLL UGF of around 30 kHz.  With this high of a UGF we used the control signal to take the spectra, and set the Preamp Gain in calibratedBeatnoteSpectrum.py to one.

Tomorrow awade and I will set up the intensity stabilization servo to try and get even lower noise on transmission.  The error signal from the North cavity is breathing in an unusual way, and we hope to get rid of this excess noise.

Attachment 1: PLL_OLG_SR785_Math_FMDevn_1kHz_PreampGain_2000_12-11-2017_195046_TF.pdf  123 kB  | Hide | Hide all
Attachment 2: PLL_OLG_SR785_Math_FMDevn_1kHz_PreampGain_2000_12-11-2017_195046.tgz  12 kB
Attachment 3: 20171113_102854noiseBudget.pdf  882 kB  Uploaded Mon Nov 13 10:41:24 2017  | Hide | Hide all
ELOG V3.1.3-