Re: [ATM] Mirror cell design

["john sherman" <atm@mail.johnspics.com>]

Hi Jeff,

>Rubber and air gaps insulate, and one problem with mirrors (other than 
>zerodur) is that uneven cooling changes the figure of the mirror.  If 
>the mirror can only cool from the front because of insulation on the 
>back, the problem is exacerbated.


True, true. And here's a problem I've seen with Zerodur. You can take it out of a warm house and it has a near-perfect figure. But because of all of the heat boiling off of it the image is ruined anyways, even with fans. So like other substrates, you still don't get a real good image till you near equilibrium. 

John






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