A fast-acting hydrogen gas source for staged pneumatic high-speed acceleration of fusion plasma fuel pellets

This report describes a possible design of a fast, high-temperature, arc-driven hydrogen gas source module, to be used in a scheme for multi-stage high-speed pneumatic acceleration of fusion plasma fuel pellets. The potential of this
scheme for operating with a moderate driving pressure at long acceleration path lengths is particular attractive for accelerating fragile hydrogen isotope ice pellets. From experiments with an ethanol-based arc unit, design parameters for
a propeller module were assessed, and with a barrel-mounted ethanol module staged pneumatic acceleration of a plastic dummy pellet was demonstrated. In experiments with a hydrogenbased, cryogenic arc unit in which 200 joules of
electrical energy were dissipated with a power level approaching S MW within 30 (is, the velocity of a 23-mg plastic pellet was increased from 1.7 to 2.4 km/s. Results in terms of barrel pressure transients and arc characteristics are described.