Re: hydrogen gaps

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

Original poster: "Luc by way of Terry Fritz <twftesla-at-uswest-dot-net>" <ludev-at-videotron.ca>

Hi Eric

Just 2 precision. First: may be I'm wrong with they electrostatic concept,
this explanation was give
to me by a technician who build and prepare experimentation equipment in a
physic lab, for him it's
more difficult to contain helium than hydrogen and that's his explanation.
Secondly:  I really don't
know how a gap in sulfur hexafluoride could perform, but if you have a seal
enclosure spark gap in
this atmosphere you will not have this gas for long: the arc will brake
this molecule in many others
in a short time but for hydrogen it will brake it in monoatomique hydrogen
and as soon as this atom
rise in the enclosure and cool a little bit they will recombine.

Luc Benard

Tesla list wrote:

> Original poster: "Eric Davidson by way of Terry Fritz
<twftesla-at-uswest-dot-net>" <edavidson-at-icva.gov>
>
> Hi All,
>
> Been following the hydrogen gap thing.  Time for my $0.02.  First of all the
> term "volatile" doesn't really mean much when describing an element or
> compound that is a gas at room temp and pressure.  Volatile means readily
> vaporizable at a low temp, and while this is certainly true of hydrogen, it
> doesnt mean much at room temperature since hydrogen has been in its gaseous
> state for 200 degrees, or so. As an example, diethyl ether is more volatile
> than water which is more volatile than motor oil, these compounds are all
> LIQUIDS at room temp, the temperature at which "volatile" is being used to
> describe them.  Hydrogen will readily diffuse through many substances which
> are usually considered to be "air tight" due to its small size.  Hydrogen
> gas is diatomic (so its "last orbit" is indeed full) and about the same size
> as helium.  Even thin mylar balloons will easily contain helium (or
> hydrogen) they eventually leak out at the string attachment, not by
> diffusion thru the mylar.  On the other hand, a standard latex rubber
> balloon will leak helium mainly by diffusion, rubber is quite porous.  If
> you had a spark gap contained in a plexiglas enclosure (1/8th inch thick or
> so) you would not get any diffusion of hydrogen thru the plastic itself.  As
> far as other leaks go, at the seams etc. its highly unlikely you would be
> able to create a leak large enough to allow hyrdogen to escape but not
> oxygen or nitrogen.  As far as the reactivity of hydrogen goes, its about in
> the middle of the scale, so to speak.  Its certainly more reactive than the
> inert gasses (which can be coaxed to form compounds with fluorine, chlorine
> and even oxygen) and nitrogen, a bit less reactive than oxygen and much less
> reactive than fluorine and chlorine.  My guess is that a spark gap operating
> in a PURE hydrogen atmosphere would be rather uneventful from a chemical
> standpoint. Yes, maybe tiny amounts of metal hydrides would form, but thats
> about it.  Obviously any oxygen or other reactive gas in the mixture would
> change the forcast drastically, but I'm assuming the idea is to quench the
> arc, not create an explosion.  I guess my question is: Why hydrogen? Because
> it was used in old thyratron tubes? If you want a more insulating gas try
> sulfur hexafluoride, it would be a much better choice in my opinion. Its
> relatively nontoxic, non flammable, non reactive and fairly inexpensive in
> lecture bottle quantities. Hope this helps. Coil safe.
>
> Eric Davidson
> edavidson-at-icva.gov