Electrum waveforms, was: Then what's the topload FOR?

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

Original poster: "Bert Hickman by way of Terry Fritz <twftesla-at-qwest-dot-net>" <bert.hickman-at-aquila-dot-net>

Peter and all,

I've added some pictures that may help clarify what the leader and
streamer zones look like, the first from Bazelyan and Raizer (Lightning
Physics and Lightning Protection), and the other from fellow coiler Sue
Gaeta on one of her coils. Capturing the actual streamer region can be a
bit tricky, and Sue's picture is among the best. 

You can easily see the brighter, more conductive leader(s) and the
diffuse streamer region beyond the tip(s) of the leader(s). BTW, most
coilers mistakenly call the true arrested leaders streamers, and call
the true streamers corona...  :^)

The pictures can be seen at:
http://hot-streamer-dot-com/temp/leader-streamer.jpg
http://hot-streamer-dot-com/temp/P13000073.jpg

Best regards,

-- Bert --
-- 
Bert Hickman
Stoneridge Engineering
Email:    bert.hickman-at-aquila-dot-net
Web Site: http://www.teslamania-dot-com

Peter Lawrence wrote:
> 
> Bert,
>      is it believed that the 7 HF oscilations in the 2-us/division B-waveform
> represent streamer "leaders" forming, that the ?-foot arc produced at the
> time this oscillograph was taken was formed in 7 increments.
> 
> Do people think that "leaders" form at a constant length, and that for a
> smaller TC there would only be one leader jump, and that for larger TCs
> generating larger sparks that there could be multiple leader jumps. OR
> is there some reason why leader jumps would be shorter in a small TC and that
> their sparks would also grow in several smaller jumps.
> 
> and why are there these HF oscillations only on the positive(?) excursions
>  of the current into the topload - do TC sparks only break out on one
polarity
>  of the resonant oscillation (that would explain how the coil form gets a
>  net elecrete charge sometimes).
> 
> and why are there hugh negative current swings in this graph, that would
>  indicate that during streamer formation / leader growth that current is
>  oscillating???
> 
> 
> This is why I think that a streak photo of a TC spark formation, especially
> if it could be coordinated with the oscillographs of the type they took of
> Electrum, would be very enlightening to us TC builders/enthusiasts.
> 
> -Peter Lawrence.
> 
> > Greg was actually able to measure currents flowing from the output
> > terminal to propagating streamers! Some of these measurements can be
> > seen at Greg's site:
>   http://www.lod-dot-org/electrum/electrumspecs.html
> >
> >
> > The following URL's show the very fast current surges during streamer
> > propagation, as well as some associated higher frequency ringing. Both
> > are superimposed upon the much lower frequency (~38 kHz) waveform of the
> > resonating secondary-topload system. In particular, look at the 20, 10,
> > 5 and 2 uSec/div traces. These show coil-to-topload current (upper
> > traces) and topload-to-streamer current (lower traces) - you can very
> > clearly see the brief, high amplitude spikes which correspond to leader
> > propagation:
> >  http://www.lod-dot-org/electrum/sphere20us.jpg
> >  http://www.lod-dot-org/electrum/sphere10us.jpg
> >  http://www.lod-dot-org/electrum/sphere05us.jpg

msnip...