Richard Clark wrote:


The capacitor is called a Marx bank (some cold-war irony there) in a
Explosively Pumped Flux Compression Generator. There are issues of
self shorting inductors wound around cylindrical explosive charges and
reams of discussion which all basically devolves to very simple and
fundamental LC with peak IR relationships.

Erwin Marx of the eponymous Marx bank has no connection to the Marx of
political theory. Marx published his papers describing the design of
his impulse generator in the teens or twenties, as I recall.


Flux compression generators are different. I suppose one could use a
FCG to charge a Marx bank, which would self erect, but I don't know that
would buy much in a weapons context.

The discharge time of a Marx is limited by the stage
capacitance/inductance. The fact that you stack a bunch in series helps
reduce the C, but the series L and R exactly counteracts it. The big
advantage is that once you get outside the generator, higher voltage
lets you have higher di/dt on the rest of the circuit, but that presumes
the rise time of the Marx is faster than the limit imposed by the load
R/L/C.

There are better ways to make very fast high voltage pulses, if that's
your goal. Fruengel's books on "pulse discharge" provide a plethora of
ideas.

Ultimately, the limit is the propagation speed in the conductors (so
schemes using transmission lines are popular: Blumlein published one in
the 40s(?) that's used a lot)