Re: ATM Active mirror figure correction?

[Richard Schwartz <richas@idt.net>]

Actually, you might improve things by spreading out the figuring load
over one or more continuous rings.   A good way to calculate the result
for mirrors of constant thickness is to use Selke's formula.    I have
no longer have this around, but I have transmitted it to several list
members as a Mathcad document.  Perhaps somebody could recover it.

Selke's formula is much faster than finite element analysis.

. .  . Richard
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Date: Mon, 26 Jul 1999 21:38:51 -0700
From: ScifiGuy <scifiguy@pacbell.net>
Subject: Re: ATM Active mirror figure correction?

I am by no means an authority, but on an intuitive level, it
seems to me
that there would be an upper limit to the mirror size that
would lend
itself well to a single tensioning bolt in the center for
parabolizing.
For instance, a very large, thin mirror might deform in a
manner that looks
more like a cone than a parabola.  It would be interesting
to see a program
such as PLOP for simulating tensioning bolt arrays affixed
to the backs of
thin mirrors.

- --Mike Selfridge