Explanation of the positive E.S. charge

To: tesla-at-pupman-dot-com
Subject: Explanation of the positive E.S. charge
From: richard hull <rhull-at-richmond.infi-dot-net>
Date: Mon, 27 Jan 1997 11:08:46 -0500 (EST)
Subscriber: rhull-at-richmond.infi-dot-net Mon Jan 27 22:15:37 1997
All,

A while back we were musing over where the positive charge comes from in gap
operated Tesla coil.  Well, thanks to a bit of digging, now that issue is
settled, I think.  If we let a DC or AC high voltage leak slowly and quietly
into the air as mild corona (as in an ionizer), we are emitting electrons
and thus negative charge.  I have measured this negative charge around two
ionizers which I have with my Keithley electrometer.

With the tesla coil we are pulsing near megawatt level blasts of peak energy
into the output resonator. (Even in small table top models!)  With the take
off rod I use in the E.S. experiments, especially one with high work
functions and needle points, we are ripping and accelerating very high
energy electrons from the metal's surface in a field which is often 10s of
megavolts per meter.  This is field emmision with a vengance, in air!

These electrons will immediately impact air atoms! (almost zippo mean free
path)  Oxygen, Nitrogen and Argon atoms are instantly ionized positively.
These tremendously energetic electrons will literally rip electrons from the
orbits of these atoms, and often not just one electron either!  The result
is a huge mass of secondary electrons which are themselves energetic, etc.
This leaves the area about the immediate vicinity of the terminal loaded
with ultra short lived high energy electrons.

Also we have a large number of positive ions with much longer lifetimes ( up
to 10,000 times longer lived) fleeing the area by impact and coulombic
acceleration (repulsion).  This explains the absolute absense of the
negative charge anywhere outside of the Tesla coil's sparking circle.

This also explains the failure of the tube and solid state coil to produce
detectable charge elements at range.  They are not true "gap" type switches
and the system capacitors are not of the size and the voltages are not as
high as in gapped systems.  This means a real pip-squeak pulse of energy is
present much more often from the output resonator, too.  Thus, the average
energy might be the same but the peak energy at any given time is always low
and this much gentler action results in a willy nilly sort of mixed bag of
plus and minus elements which are not energetic or coulombically
accelerated.  They recombine in the area immediately about the discharge.

I have just finished a long and tedious read of an excellent reference text
on this subject.  It is old, but thorough, as are all older books.  The Phds
who wrote this old book supply the math but don't use it to the exclusion of
countless hundreds of real world examples which are rarely presented in this
day and age where math appears to be enough with no real solid examples.

"Theory of Gaseous Conduction and Electronics" by Maxfield and Benedict, Mc
Graw Hill, 1941

Specifically, chapters 7-12.  This is superb reference and I rate it up
there with "Pulse Generators" in the MIT radiation laboratory series!  

Both of the above books are in my library now.

Richard Hull, TCBOR