Spark gap Idea
Subject: Spark gap Idea
Date: Tue, 28 Mar 1995 17:50:36 -0500 (EST)
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After reading the book I mentioned on High Power Swithcing I had a
little thought: What could one possibly do to increase the quench time and
at the same time reduce the resistance of the static spark gap? Poss ans ..
liquid gaps..... but oil gets contaminated by holding sputtered metal
in suspension and water has to be highly filtered and clean to have a
decent breakdown voltage.
I just tried liquid nitrogen in a little test set-up to see
roughtly what kind of breakdown voltage it has. It seems to be
approximately like mineral oil (by eye).
Should quench really well due to very low temp LN2 surrounding
gap. Metal electrodes kept very cool. Will not suspend sputtered
metal. Inherently clean.
Higher current densities are predicted (lower effective resistance)
since there are orders of magnitude more ions/electrons available
from the liquid. This should still be true in the high density
vapor generated from the spark.
BTW, one minor discovery: at LN2 temps (77Kelvin) the breakdown voltage of
polyethylene and many other materials goes up rather dramatically. How
about immersing a whole secondary/extra coil in LN2 as insulation?