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Message ID: 1354     Entry time: Wed Mar 4 12:38:07 2009
Author: Alberto 
Type: Update 
Category: Computer Scripts / Programs 
Subject: 3f locking simulations 
I simulated the REFL signals demodulated at the differential frequencies of the sidebands (f2-f1), at their summed frequencies (f2+f1). I also simulated their combination as in the Double Demodulation.
I repeated the simulation for:
- Old (current) 40m
- 40m Upgrade
I'm attaching the results to this elog entry.
The plots show how the signal varies exploring the two-dimensional space of the demodulation frequencies (differential and sum).

 Both the Upgrade and the Old40m's signals look anomalous since the zero-crossing point does not change with the demodulation phases.

I suspect there's is a problem with the optickle model of the 40m.

Attachment 1: 23_3f_40mOld_DDplots.pdf  17 kB  | Hide | Hide all
23_3f_40mOld_DDplots.pdf 23_3f_40mOld_DDplots.pdf 23_3f_40mOld_DDplots.pdf
Attachment 2: 59_3f40m_Upgrade_DDplots.pdf  21 kB  | Hide | Hide all
59_3f40m_Upgrade_DDplots.pdf 59_3f40m_Upgrade_DDplots.pdf 59_3f40m_Upgrade_DDplots.pdf
Attachment 3: 20_3f_AdvL_DDplots.pdf  16 kB  | Hide | Hide all
20_3f_AdvL_DDplots.pdf 20_3f_AdvL_DDplots.pdf 20_3f_AdvL_DDplots.pdf
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