40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
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Message ID: 736     Entry time: Thu Jul 24 21:04:58 2008
Author: rana 
Type: Update 
Category: PSL 
Subject: FSS 
Since Jenne and Yoichi are going to finish up their refcav/FSS work in the morning I decided to
look at the trends. I set the RF modulation level from 10.0 back down to 7.5 so that we would
have the same RF modulation depth as before. I also set the FSS common gain and its nominal to
1.0 dB since it seemed more stable this way.

With 7.5, the transmission of the refcav is ~6.9 V. It was around 0.7 V before so there's already
been a factor of 10 improvement in the power since the work started. In addition to the mode matching
work which is about to commence, we should attenuate the RC TRANS with a real mirror (not ND) so that
the camera and PD don't saturate. We should also do the same for the REFL PD and camera and make sure
to put in a steering mirror for the REFL PD and orient REFL so that it faces West (so that we can
look at its face with a viewer) and dumps its reflection.

Since the common gain is so low now, I expect that we will want less light in total. We can achieve
this by turning down the RF drive to the VCO.

I also fixed the MC down script which was putting the FSS common gain to the unstable +10 dB level
during the MC locking process.
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