Lightning vs. Tesla Coil Discharges

Reinhard Walter Buchner wrote:

> While reading Jim Lux´s answer to my post on filming
> TC arcs, a few questions popped into my head:
> What capacitance (roughly of course) does a cloud have?
> Is the impedance and capacitance of a lightning strike
> comparable to a TC discharge? 

If you consider a typical lightning strike at about
1oo,ooo,ooo volts, that delivers about 30 coulombs 
in the main strike, the effective capacity is about
30/10^8 = 0.3uF.
A representative peak current in the return stroke is
about 2o,ooo amperes.  10^8/20k = 5000 ohms.
Raw TC discharges appear to be in the 100k ohm range.
Capacitor boosted TC discharges are considerably lower
in impedance, usually less than 10 ohms.

> This brings another thought to mind. What would happen
> if we could (in some way) make a discharge path which
> is surrounded by a gigantic magnetic field? This should
> keep the plasma bundled and very hot. What would happen if we
> constructed this magnetic field similar to a coil gun? In
> other words using not one, but several magnetic coils along
> the discharge path. Could one accelerate or even stretch
> the actual coil discharge?

Yes.  In fact, the magnetic field produced by the arc
current itself will contain the plasma quite nicely if
the current rises fast enough.  We've gotten an 110kV
capacitor bank to arc 35ft with an exploding wire, using 
this effect.