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Entry  Mon Dec 19 22:05:09 2016, Koji, Summary, IOO, PMC, IMC aligned. The ringdown PD/Lens removed. 
    Reply  Wed Dec 21 21:03:06 2016, Koji, Summary, IOO, IMC WFS tuning DSC_0142.JPG
       Reply  Thu Dec 22 18:39:09 2016, Koji, Summary, IOO, IMC WFS tuning WFS_error_noise.pdfWFS_error_noise_chans.pdf
          Reply  Fri Dec 23 20:53:44 2016, Koji, Summary, IOO, IMC WFS tuning DSC_0144.JPGDSC_0145.JPG
             Reply  Fri Dec 23 21:05:56 2016, Koji, Summary, IOO, IMC WFS tuning IMC_WFS_segment_TF.pdfIMC_WFS_channels_TF.pdfIMC_WFS_161221_table1.pdfIMC_WFS_161221_table2.pdfIMC_WFS_161221.xlsx.zip
                Reply  Sun Dec 25 14:39:59 2016, Koji, Summary, IOO, IMC WFS tuning 
                   Reply  Mon Dec 26 12:45:31 2016, Koji, Summary, IOO, IMC WFS tuning IMC_REFL_TRANS_26hrs.pngIMC_TRANS_P_Y_26hrs.png
          Reply  Thu Dec 29 13:22:21 2016, rana, Summary, IOO, IMC WFS tuning 
             Reply  Thu Dec 29 16:52:51 2016, Koji, Summary, IOO, IMC WFS tuning 
                Reply  Thu Dec 29 21:35:30 2016, rana, Summary, IOO, IMC WFS tuning Screen_Shot_2017-01-03_at_5.55.13_PM.png
                   Reply  Tue Jan 24 01:04:16 2017, gautam, Summary, IOO, IMC WFS RF power levels MC1_misalignment.png
                      Reply  Fri Jan 27 00:14:02 2017, gautam, Summary, IOO, IMC WFS RF power levels 
Message ID: 12688     Entry time: Thu Dec 29 13:22:21 2016     In reply to: 12682     Reply to this: 12689
Author: rana 
Type: Summary 
Category: IOO 
Subject: IMC WFS tuning 
  • For the rough calibration below 10 Hz, we can use the SUS OSEM cal: the SUSPIT and SUSYAW error signals are in units of micro-radians.
  • It seems from the noise plots that the demod board is now dominating over the whitening board noise.
  • If the RF signals at the demod input are low enough, we can consider either increasing the light power on the WFS or increasing the IMC mod. depth.
  • We should look at the out-of-lock light power on the WFS and re-examine what the 'safe' level is. We used to do this based on the dissipated electrical power (bias voltage x photocurrent).

At Hanford, there is this issue with laser jitter turning into an IMC error point noise injection. I wonder if we can try out taking the acoustic band WFS signal and adding it to the MC error point as a digital FF. We could then look at the single arm error signal to see if this makes any improvement. There might be too much digital delay in the WFS signals if the clock rate in the model is too low.

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