From: "B2"
Date: Sat, 11 Nov 2000 12:28:59 -0500
Subject: Re: [TSSP] NSVPI - Latter Results
Hi Paul, All,
> Let me guess that the resistive phase is a short period of constant
> resistance during which the arc gets established. It looks to be on
> the order of nanoseconds and is presumably relevant to fast=20
> pulse discharges in accelerator and fusion supplies. I take it we
> can ignore this resistive phase, since tesla gaps conduct for many
> tens of microseconds?
> Paul Nicholson,
> Manchester, UK.
There ought to be an initial loss due to channel formation =
(resistive loss). Succeeding losses are possibly caused by plasma =
maintenance, ionizations and reionizations at the voltage reversals, and =
cathode spot formation and reformation on the opposite electrodes at =
voltage reversals. =20
Mitigation of the first loss could be via externally triggering the =
gap. The energy loss (resistive phase) is now in the trigger circuit. =
Even there, the losses could be minimized with optimized triggering, =
i.e., fast risetime and multiple streamer formation with concomitant =
multichanneling leading to lower overall channel resistance and =
inductance.
Mitigation of the remaining two losses could be via a scheme that I =
am still pondering. Suppose two spark gaps are constructed. Suppose =
each gap is isolated by a high voltage high "pulse" current diode. This =
scheme would force the gaps to be unidirectional during the entire =
conduction period. Ion and cathode spot leftovers would be preserved =
(within the normal decay time constants). Since each gap would be =
incuring only half of the losses, it would quench faster. There is the =
possibility that a trigger circuit could be designed to also aid in gap =
deionization and quenching. There is the question as to whether such =
diodes can be obtained with low enough switching losses. =20
Anyone think that any part of this would be feasible?
Cheers,
Barry
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.