Re: TC Sparks and Arcs (Was - High Voltage Snubber caps

["Bill Lemieux" <gomez-at-netherworld-dot-com> (by way of Terry Fritz <twftesla-at-uswest-dot-net>)]

On that fateful day 8/5/00 11:01 AM, thus spake Tesla list:

> The formation of sparks require the presence of an atmosphere. The light
> that you see is emitted by electrons recombining with ionized atoms.

 Note that the orbiter seldom gets above 185 miles (it flew as high as 200
miles for the Hubble placement mission), and that there is still significant
atmosphere at this altitude.  It's not something you could breath, or
measure on a typical barometer, but it's enough that it exhibits drag on
orbiting spacecraft!
 
 "Outer space" is far from empty, even at geosynchronous orbit altitudes
(~22,000 miles, depending on the mass of the spaceraft).  In fact, there is
miniscule, but non-zero force exerted on spacecraft by the solar wind,
something that has to be accounted for in precision-pointing missions such
as certain earth-imaging platforms.

 At a mere 80 - 150 miles altitude, I would certainly expect a visible glow
discharge.

> Without a gas present, electrons would continue to be emitted from
> the metalic terminal when it is sufficiently negative (as in a cold
> cathode vacuum tube), and attracted back when it is positive, but
> nothing will be seen (or heard, by the way). X rays may be produced.

Only if the x-ray threshold voltage for the target material (dependent on
density) is reached.  Don't make your toroids out of tungsten for this
project!  ;)

- Gomez (Bill Lemieux)

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Is it weird in here or is it just me?