Re: Gap Question

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

Original poster: Bart Anderson <classi6-at-classictesla-dot-com> 

Hi Malcolm,

Tesla list wrote:

>Original poster: "Malcolm Watts" <m.j.watts-at-massey.ac.nz>
>Hi Bart,
>
>On 25 Feb 2004, at 21:24, Tesla list wrote:
>
> > Original poster: Bart Anderson <classi6-at-classictesla-dot-com>
> >
>
>It is a limit imposed by circuitry external to the discharge, for
>example a resistor or an inductor (i.e. the internal impedance of the
>power source).

Ah yes, I see. Sure, that makes perfect sense.

> > A larger number of pathways should increase the current value at any
> > point in time.
>
>But one doesn't normally get multiple pathways in an arc, at least at
>STP does one?

Your right, I shouldn't have used the term pathway. I simply meant the 
expansion and retraction of the cross-sectional width of the the arc with 
relationship to the current flowing through the conducting mass. But as you 
say, external limits or maybe I should use the the term 'primary surge 
impedance".

>A conduction channel of hot ions is favoured. A glow
>discharge in a rarified gas is another matter. Unlike a welder, the
>gap goes out periodically which doesn't favour a plasma type
>discharge like that you can draw from an arc welder although I
>suppose one could argue that a plasma is present while the primary is
>ringing and the gap is alight. For nature's best demonstration of
>spark behaviour, lightning formation warrants some attention.

Although there is a wealth of information regarding spark formation, many 
of theory's take the form of "pre-spark" processes or streamer processes. 
When looking for information regarding the above, I can't seem to scrounge 
up much.

>I cannot agree that pipe spark gaps simultaneously conduct along their
>whole length as at least one person has said.
>
>Malcolm

No, I can't either, not simultaneously in a spark gap with anode and 
cathode electrodes. Very different from a space charge streamer. Of course, 
here again is where a high speed camera would be pretty easy to confirm 
(there must be some photographic evidence somewhere).

Thanks and take care,
Bart