If such a switch work well, one could also use NaK or molten Lithium or such.
A former vortex list member has a 50 kilojoule at ~ 1100 volts capacitor bank
sitting in his barn, "available at a bargain basement price plus Shipping and
Handling to a qualified researcher."
We had those professional types on this list once before Bill B let it become an anything
goes, forum. :-(
Fred

