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Entry  Wed Mar 20 22:18:28 2013, tara, Notes, RefCav, estimated beat frequency 
    Reply  Fri Apr 5 13:56:01 2013, tara, Notes, RefCav, estimated beat frequency 
       Reply  Sat Apr 6 09:32:35 2013, rana, HowTo, TempCtrl, estimated beat frequency 
          Reply  Mon Apr 8 15:15:06 2013, rana, HowTo, TempCtrl, estimated beat frequency 
             Reply  Sun Apr 14 16:51:21 2013, rana, HowTo, TempCtrl, estimated beat frequency 
Message ID: 1144     Entry time: Mon Apr 8 15:15:06 2013     In reply to: 1143     Reply to this: 1147
Author: rana 
Type: HowTo 
Category: TempCtrl 
Subject: estimated beat frequency 

Isn't heating up one cavity enough? The goal is to keep the beat frequency constant, so we need to control the differential length between the two cavities. The first cavity can sit still, the second one can be heated up (for enough cooling rate). We plan to use a frequency counter to change beat frequency to the servo's error signal for feedback to the second cavity. 

Anyway, I still have to check if both heaters are working or not.

Quote:

I would have guessed that you heat both cavities. Unless they are both at an elevated temperature, how can you control their individual temperatures?

The cooling rate (and thus the bandwidth for control) is determined by the steady state temperature. I would guess that each cavity needs to be at least 35 C in order to have some headroom.

 

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