From: "B2"
Date: Sat, 7 Oct 2000 13:47:16 -0400
Subject: Re: [TSSP] Progress report 28th Sep 2000
Hi Mark,
> I have also been doing a number of computer simulations based =
on
> coupled lossy LRC circuits and have recognized how important primary =
losses
> are in impacting output energy. I am now looking at peak energy =
coupled
> into the secondary rather than peak voltage, since it appears to have =
a
> better relationship with spark length. I would like to hear the =
group's
> comments on this.
> Mark S. Rzeszotarski, Ph.D., MetroHealth Medical Center,Radiology
> Department, Cleveland OH 44109-1998
=20
Two references:
First J.C.Martin in the book "J.C.Martin on Pulsed power" gives =
relations for spark gap inductance, risetime, and impedance. The first =
article is on page 287 titled "Duration of the resistive phase and =
inductance of spark channels" where he gives the formula for spark gap =
impedance as ((1.7 * L)/ r) + Z where L is the inductance of the spark =
channel, r is the length of the resistive phase, and Z is the impedance =
on Ohms of the circuit driving the spark gap. In another article titled =
"Multichannel gaps" he gives his famous formula for the resistive phase =
of spark formation as (88/(Z**(1/3) * F**(4/3))) * =
(rho/rho-zero)**(1/2) where the time is in nanoseconds, Z is the =
impedance driving the plasma channel in Ohms, F is the field along the =
chammel in units of 10 KV per centimeter, rho is the density of gas =
used, and rho_zero is the density of air at STP. Rho will change with =
bang rate.
Second: That reference for the use of multiple tuned primaries can =
be found in The Proceedings of the Institute of Radio Engineers, Volume =
4, 1916, pages 463 to 490, by John Stone Stone. John Stone Stone gets =
into Fourier decomposition theory. He shows how relating the =
frequencies of the primaries can result in a waveform with low spark gap =
losses by minimizing the resistive phase and increasing the conductive =
phase. John Stone Stone also shows how to make a "push pull" primary =
circuit with two spark gaps, one on each side of the primary! =20
Cheers,
Barry
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.