I wrote:
 > To produce long streamers, really the coil just needs to
 > develop enough voltage to start the breakout, and then be
 > able to back that up with plenty of charge (ie a big toroid)
 > and enough power to keep the streamers hot and low resistance.
 > Therefore you're more likely to find a simple relationship
 > from input power * efficiency to arc length.
I wish I could justify this with some data, but measurements
have not yet been performed (as far as I know) on a TC.
Udo Lenz wrote:
 > ... it seems a bit extreme. I can't imagine an endlessly
 > growing streamer given infinte power but just a certain
 > voltage.
There'll be a voltage drop along the arc and at some point
the arc will reach sufficient length for the tip not to have
a local field strength high enough to make further extension.