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Entry  Thu Nov 18 00:28:28 2010, koji, tara, DailyProgress, NoiseBudget, Noise from scattering light near the cavity's foam cap opening beat.pngVCO_RCNOISE.pngcompare.pngplot_code.zipSCRN0130.zip
    Reply  Thu Nov 18 03:10:03 2010, Koji, DailyProgress, NoiseBudget, Noise from scattering light near the cavity's foam cap opening IMG_3716.jpg
       Reply  Thu Nov 18 14:17:45 2010, tara, DailyProgress, NoiseBudget, Noise from scattering light near the cavity's foam cap opening 
          Reply  Thu Nov 18 15:09:22 2010, Koji, DailyProgress, NoiseBudget, Noise from scattering light near the cavity's foam cap opening 
             Reply  Thu Nov 18 21:42:33 2010, tara, DailyProgress, NoiseBudget, Noise from scattering light near the cavity's foam cap opening Beat_VCO.png
                Reply  Thu Nov 18 22:23:20 2010, Koji, DailyProgress, NoiseBudget, Noise from scattering light near the cavity's foam cap opening 
                   Reply  Fri Nov 19 01:21:53 2010, tara, DailyProgress, NoiseBudget, Noise from scattering light near the cavity's foam cap opening VCO_TF.png
Message ID: 397     Entry time: Thu Nov 18 03:10:03 2010     In reply to: 396     Reply to this: 398
Author: Koji 
Type: DailyProgress 
Category: NoiseBudget 
Subject: Noise from scattering light near the cavity's foam cap opening 
  • Even after the removal of the Al tip, the scattered light noise looks still exist.
  • Particularly I still could see apparent fringe wrapping when I shook the table or touch the foam construction.
     
  • I still could not reject the possibility of the backscattering towards the PMC.
  • We had the fringe wrapping up to ~200Hz. This corresponds to the motion of the scattered body or the optical
    path for the scattered light by ~100um. Is that possible?
  • The VCO feedback and the beat note PLL feedback seemed to have the same information so far.
  • The lollipops at the trans mission ports are terrible. They are mechanically incorrect.
  • What is the correct conversion between the VCO feedback and the beat note PLL feedback??
    Both are VCO feedback signals but the slope looks different. Need precise investigation.

 

 

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