Subsonic Gas Target (intense 14-MeV neutron source for thermonuclear fusion)

Nuclear reaction processes can be carried out at high intensity by directing an intense charged particle beam into a rapidly moving gas flow, i.e., a gas target. The gas target which is self-cooled, self-replenishing, and virtually indestructible can withstand enormous heat-loading, hence achieving high radiative intensity. A new gas target type is described, the Subsonic Gas Target (SGT), which is shown to have several advantages over other gas target types which have been proposed as intense 14-MeV neutron sources for thermonuclear fusion engineering studies. These advantages are increased siting volume for irradiated samples, decreased mass flow (i.e., gas pumping cost), and less extreme stagnation tank conditions. The general operating characteristics of SGT's are set out as applicable to any combination of beam particle and gas flow. It is found that SGT operation is fully given by the specification of five parameters: beam power density P, ratio of heat input to inlet flow stagnation enthalpy Q, stagnation tank temperature T0s, original beam voltage J^, and gas channel diameter D.