The reflex switch: An opening switch for terawatt-level power amplification in vacuum

Pulsed power systems based on power amplification of magnetic energy in vacuum offer dramatic advantages in compactness, power scaling, and cost over present-day technology. We report the successful operation of a vacuum inductive storage system which uses the “reflex switch,” a fast-opening, high-current switch, to produce pulsed compression in vacuum. In our best results to date, a compact vacuum magnetic store (1 m long, 15 cm diameter) produced a 1.8-MV, 10-ns risetime, 20-ns FWHM inductive voltage pulse after being charged to 160 kA over 50 ns, with the reflex switch “closed.” Then the switch was “opened” in 10 ns, giving more than an order-of-magnitude increase of impedance at a rate of over 1.0 ohm/ns, choking the inductor current and producing the power-amplifying voltage pulse, which we used to generate an intense REB. Energy transfer from the magnetic store to the REB was highly efficient. Switch opening is controllable and is based on a transition from the reflex triode mode to the bipolar Langmuir diode mode of particle flow.