Re: SSTC modelling- any math geniuses?

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

Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz> 

On 24 May 2004, at 11:47, Tesla list wrote:

 > Original poster: "Steve Conner" <steve.conner-at-optosci-dot-com>
 >
 > OK I messed up...
 >
 > I have been corresponding with Richie and I am forced to admit the
 > "magnetizing current" model is a good one and the "leakage inductance"
 > one is a red herring. The model is described on his website.
 >
 > We are now working on extending the model to DR/ISSTCs, and trying to
 > factor in a quantitative way of dealing with corona loading. We have
 > already figured out that the tuned primary works its magic by acting
 > as an impedance matching device and can be modelled as an L-match.
 >
 > Now here is a question for the math geniuses... Can we take the corona
 > load impedance, as seen at the top of the resonator, and transform it
 > to an equivalent impedance at the base, using the well-known quarter
 > wave stub formula:
 >
 > Zbase=(Zo^2)/Ztop
 >
 > Where Zo is the characteristic impedance of the "transmission line",
 > which I suppose would be sqrt(L/C), L being the secondary inductance
 > and C=(Ctoroid+Cself+Ccorona)?

The odd experiment I've done in terminating a resonator with a fixed
resistance suggests the formula holds, at least loosely. That was
some time ago when it was suggested as an explanation for the
behaviour of a large CW coil in terms of blowing fuses and MOSFETs vs
being able to feed a useful amount of power in. Some time around '96
as I recall.

 > If so it all becomes rather nice and we can model the ISSTC after
 > breakout as an "antenna" with "radiation resistance", being base-fed
 > from a "transmitter" through a L-match "antenna tuner" :)))
 >
 > There is the complication that the corona load varies with power as
 > the streamers get longer and hotter, but we'll burn that bridge when
 > we come to it :))))

That is the real problem and gets much worse when the streamers
connect with a target.

Malcolm