Triggered Gap losses

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

Original poster: "Jim Lux by way of Terry Fritz <twftesla-at-qwest-dot-net>" <jimlux-at-earthlink-dot-net>

One way to reduce triggered gap losses is to run them at high pressure.
Shortens the length of the arc (reducing drop along the arc column), and
provides more atoms in the path (reducing the drop even more).  Cooling
might be an issue, though... unless you are running a triggered high
pressure blast gap.  However, if you think of electrodes that are
hemispheres stuck in the middle of a big flat plate (which is what Maxwell
uses in many of their gaps...), you might get enough heat sinking to keep
the electrodes/gas at a reasonable temperature, even in a sealed system.
I'm thinking 1 cm diameter hemispheres in the middle of a 10-20 cm diameter
disk.  A couple of O rings seal the disks to an insulating spacer in
between using nylon screws (or metal screws into the body of the spacer).
Say you want the hold off to be 30 kV.  At 1 Atm, you need about 1 cm of
space between the hemispheres, but run at, say, 5 atm, and you only need
0.2 cm (that is, the spacer would need to be 1.2!
  cm thick
(0.5 for one electrode, 0.2 for the gap, 0.5 for the other hemisphere).

Does anybody have a "typical" power dissipation in the spark gap?  Is it
10W, 100W, or what? With that, I can do a quick thermal
resistance/temperature rise calculation.