Re: Crucible Capacitors for Marx Generators

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: Jim Lux <jimlux-at-earthlink-dot-net> 

Places that specialize in glass blowing/casting (lamp working, more 
precisely), as well as industrial suppliers, will have crucibles that are 
alumina, silica, magnesia, etc.  Alumina is of some interest because of the 
high dielectric constant (10), compared to glass/silica, etc.  Don't know 
about magnesia.  What I would be concerned about is trace contaminants in 
the porcelain that don't affect the thermal and chemical properties, but 
have huge effects on the electrical properties (i.e. loss, resistivity, and 
breakdown strength).

How would you go about making a capacitor from these?  Like a beer or wine 
bottle cap?  By plating metal onto them (evaporating metal)?

Flat ceramic blanks are also available cheaply.  Coors (same as the beer) 
is a big manufacturer of this stuff, by the way.

One might also look into thin crystalline layers of aluminum oxide (Al2O3) 
aka sapphire. High dielectric constant, high breakdown strength, 
mechanically very strong.  Fabrication might be a bit tricky (maybe CVD or 
similar, using a microwave oven), but at least you'd be able to claim that 
your TC caps were sapphire dielectric.

At 08:14 AM 8/29/2003 -0600, you wrote:
>Original poster: Vivek Babtiwale <dr_vek-at-yahoo-dot-com>
>Has anyone made capacitors out of crucibles? The
>crucibles available through tri-ess science
>
>http://www.tri-esssciences-dot-com/crucibles.htm
>
>are porcelain and would make great caps, and they
>range in price from $2.61 to $6.48, in quantities of 12.