vansig wrote:

a 13.5 cm diameter copper pipe will rise to full current in 10 ns. is this good enough?

if we model as an RLC series circuit, then based on recently-measured 1.8 microsecond rise time, it seems like circuit inductance is a factor ~3000 greater than where it needs to be. what does this translate to? larger diameter conductor? coaxial shield? change in overall geometry?

Here is a hard line cable, used in broadcasting. what kind of feed wires are used in FF1?
http://en.wikipedia.org/wiki/File:Coaxialcableoneandfifthofan.jpg