Dex Dexter wrote:
Impractical DRSSTC yes. But,theoretically possible also yes.From what I know from HF power antennae theory , steady state high frequency excition can more easily break nonuniform gap than D.C. or low frequency (60 hz).HF requires less voltage ,or if you like less average breakdown field for the same rod-rod gap. Things get changed with an optimal rise time monopolar positive pulse when voltages become really high and bigger gaps . But there must be also an optimal DRSSTC envelope rise for given gap,and due to smaller average breakdown field HF optimal pulse should arc longer than monopolar pulse.Dex
Hmmm. I don't know that RF makes that big a difference (maybe a factor of 2?) Can you cite a reference that says otherwise? The differing breakdown voltages in a particular gap for different pulse shape/rise time/polarity is well known and there's no surprises there. You can run a very short pulse and not have breakdown in a gap that would breakdown at DC, for instance.
One wants to be careful about steady state RF phenomena, because of resonance effects. Using a resonant ring of waveguide is a well known way of testing microwave components for high power breakdown without needing a very high power source.
There are, however, laws of physics reasons preventing you from making an arbitrary waveshape on a given electrode configuration, which is why really long sparks that are self propagating (not drawn arcs) come from really high voltages. You can put all the DC power in the world behind an electrode charged to 100kV, and you're not going to get extreme length sparks from it.
Certainly, there are DRSSTC optimum envelopes, and one can either build your own coil and empirically determine them, or spend a LOT of time trying to model it (which I think is doomed to frustration, because spark growth and development are just not that well understood)
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