Re: Crucible Capacitors for Marx Generators

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

Original poster: "Harold Weiss" <hweiss-at-new.rr-dot-com> 

Hi All,

I saw a NASA tech brief (?) awhile back that had reference to a dimond film
cap.  The dimond film was being used for some type of high voltage pulse
capable cap.  I tried looking up the company, but all I got was some defence
contractor, and could not access the division that was working on it.  But
just think, 250KV across not much more than a mil, and we would have a dream
capacitor.

David E Weiss

 > 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.
 >
 >
 >
 >