Re: Useless questions

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

Original poster: "Paul Nicholson by way of Terry Fritz <twftesla-at-qwest-dot-net>" <paul-at-abelian.demon.co.uk>

[3cm radar scattering from topload]
Having thought about this, and after a bit of reading, it seems 
that ionised gas molecules in the vicinity would not be expected
to contribute either to a radar return, or to enhancement of
subsequent streamer formation.  It needs the greater mobility
of free electrons to perform both functions.  In view of the
very short time that free electrons can survive, we would therefore
not expect to be able to use a simple radar to look for any
effects persisting between RF cycles, or between bangs.  Such
things as hot air channels, etc, would not show up on the radar.

But that still leaves open the possibility of using the returns'
doppler beat to detect the advancing 'front' of the streamers.

Jim wrote:
> the mixer diodes in these things (being optimized for doppler in
> the audio range) probably don't have that kind of bandwidth (in
> terms of parasitic C and R, forming a low pass filter..

Yes, I see the problem.

Moving in a different direction then...

Can we shine a bright light across the topload to illuminate a
screen?  Hot air channels caused by streamers might be visible
as slightly darker lines on the screen, since light passing through
a hot channel would be scattered by the altered refractive index.

Then, if the screen was viewed by a TV camera, frames grabbed both
during a bang, and between bangs, might give firm evidence that
these hot channels persist between bangs, and might even show
them being re-used at the next bang.  

It might not be too easy to grab frames synchronously at two or more
times the bps rate, but if frames were grabbed asynchronously, they
could be sorted out if the primary gap was also visible in the
image.  I recollect this kind of thing has been talked about before,
but I don't know if it's been tried.
--
Paul Nicholson
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