[ATM] Cleaning mirrors

[jlerch1 at tampabay.rr.com (James Lerch)]

----- Original Message ----- 

> Hi ATM'ers,
>
> Does anyone have any suggestions on a cheap way to do plasma cleaning on
> mirrors?   Plasma is the way they ultra clean silicon wafers and medical
> instruments.
>
> Bill Kelley

Bill,

Perhaps your confusing the method of plasma cleaning optics  in a vacuum prior
to evaporating coatings, with other methods used at atmospheric pressures.

Most professional optical facilities implement a wide array of 'normal' cleaning
methods for finished optics from soap and water to 'CO2 snow cleaning'.  However
I've never heard of plasma cleaning an optic while its still at one atmosphere
of pressure.   (But hey, who knows, maybe I'm about to learn something! :)

In addition, even plasma cleaning in a vacuum won't remove bulk contaminants
(like a finger print).  Mostly vacuum plasma cleaning is used to help drive off
molecular water clinging to the surfaces inside the chamber and convert oils
(hydrocarbons) into COx and other gaseous by products that can be pumped out of
the chamber.

With regards to the microwave magnetron idea, do a google search for "Microwave
Plasma Ball"  You get results like this one:
http://apache.airnet.com.au/~fastinfo/microwave/ball.html

I'm pretty certain I wouldn't want ANY of my precision optical surfaces anywhere
NEAR a 1KW ball of Plasma!  :)

If your interested in exotic optical cleaning methods, do some research on the
CO2 Snow Cleaning.  Seems pretty promising for amateurs with spare time!
Basically you need a bottle of Liquid CO2, A hose, and a Nozzle.  The trick is
in the nozzle that converts the liquid CO2 into a solid snow flake like shape.
The CO2 snow flakes are then ejected at high speed to 'bounce' of the optical
surface, and while they bounce they either melt or sublimate, dissolving
contaminants and effectively blowing them off the optic...

Take Care,
James Lerch
http://lerch.no-ip.com/atm (My telescope construction,testing, and coating site)

"Anything that can happen, will happen" -Stephen Pollock from:
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