Re: Strange Phenomenon In DC Powered VTTC

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: William Beaty <billb@xxxxxxxxxx>

On Fri, 18 Aug 2006, Tesla list wrote:

> You see at the very end of the video the arc all coalesce into one
> spinning arc tornado just before the fade out. I believe convection and the
> coriolis effect are at play. It would be cool to see a frame by frame on the
> original tape (I'll add it to my list). ;-)

You're seeing an effect which is also used in plasma focus fusion
experiments at the U. of Washington.  They recently found that a
laminar-flow gas jet has a velocity distribution which removes plasma
instabilities during the big pulse, allowing the experiment to run for
lots more milliseconds than usual.  (Introducing gas jets into their
vacuum chamber is a big problem!)


But coilers have known this for years:  when a TC streamer extends
vertically upwards, and if the power is fairly high, then air inside the
streamer gets hot and starts rising in a column.  The rising hot air acts
as a laminar-flow jet, and will prevent the streamer from kinking and
wiggling.  The streamer starts to look like the smoke rising from a stick
of incense, or from a cigarette.

You can also see this with a NST arc discharge if you position the
electrodes so the arc is jumping vertically.  The arc gets narrow and
smooth, sort of like a candle flame.

(((((((((((((((((( ( (  (   (    (O)    )   )  ) ) )))))))))))))))))))
William J. Beaty                http://staff.washington.edu/wbeaty/
beaty@xxxxxxxxxxxxxxxxxxx       Research Engineer
billb@xxxxxxxxxx                UW Chem Dept,  Bagley Hall RM74
206-543-6195                    Box 351700, Seattle, WA 98195-1700