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Re: Explanation of the positive E.S. charge


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

> I remove the #6 cable and replaced it with 14' of #4 welding cable.  
>The NE2 would light only about 1/2 of one electrode. I had to get close 
>to the neon lamp to see this. Surprise only 1 electrode was glowing! 

I did some more checking with the NE2 across the #4 ground wire. For
air discharges off the toroid or off a 1/2" director bump, ground is
negative and my TC's ground bar is positive. If I bring a wire from
the TC's ground bar near the toroid and generate an arc, the NE2's
electrodes both light fully (AC and a much heavier current across the
reactance of the #4 ground wire!)

I placed a stainless steel needle point on the toroid. Both electrodes
of the NE2 light (AC). I changed to a 0.5mm pencil lead; again both
electrodes light (AC). I noticed that in these cases the electrodes
were not fully engulfed in glow discharge. Just the inside halves of
each electrode and the intervening gas.

Does anyone have any idea what the reactance of 14' of #4 finely
stranded mildly twisted welding cable is?  I could find no
manufacture's name or part number on the cable. Effectively, I have
used the NE2 to determine the voltage drop across a current shunt.
Given a value for the reactance of the cable at least a ball-park
estimate of the current could be reached.

	jim