From: Paul
Date: Mon, 21 May 2001 17:18:12 +0100
Subject: Re: [TSSP] Genetic optimisation
Hi Bert, Somehow you always seem to drop in an informative post. >... [Reukema] found a progressive lowering of breakdown voltage, > by as much as 17% (about 25 kV/cm), as the frequency was increased > between 20 kHz and 60 kHz. However, no further breakdown voltage > reductions were seen between 60 kHz and 425 kHz. That sounds promising. Does the 425 kHz limit imply things change above that frequency, or is that just where his measurements stopped? > ...[Raizer] estimates the breakdown field in room temperature for > relatively long gaps (>6 cm) is about 26 kV/cm. Are we OK to extrapolate this figure to gaps of order a metre or so? > So... barring precise measurements, a good starting point for > estimating E-field for terminal breakout at Tesla Coil frequencies > might be about 25 - 26 kV/cm. That sounds very reasonable. Perhaps Terry could use this value to calculate the breakdown voltage of a test setup and compare it with the peak top voltage measured in an actual run? If they came out in the same ballpark then we would have the basis of a two pronged strategy - Marc's gathering of experimental results, plus Terry's field calculations - which between them might be able to bracket the actual values to a range narrow enough to permit meaningful modeling. With a bit of luck we might expect a reasonable match for smooth toroids, with progressively lower measured breakdowns for rougher surfaces, at which point Terry will invent a fiddle factor to adjust for the toroid material. While we're on the subject of genetic methods, a few background links, http://www.rennard.org/alife/english/gavintrgb.html http://cmp.ameslab.gov/~jrmorris/ga/ http://ai.bpa.arizona.edu/~mramsey/ga.html http://www.hao.ucar.edu/public/research/si/pikaia/tutorial.html Cheers, -- Paul Nicholson, Manchester, UK. --
Maintainer Paul Nicholson, paul@abelian.demon.co.uk.