Self-Fueling Fusion Hybrid Reactor for Space Power and Propulsion

T. Kammash (2010), JBIS, 63, pp.384-386

Refcode: 2010.63.384
Keywords: Blanket, plasma, breeding, fissile, subcritical

Abstract:
A fusion hybrid reactor whose fusion component is the Gasdynamic Mirror (GDM) is presented as a potential energy source for utilisation in space exploration. Such a reactor will consist of a fusion component whose primary function is to supply neutrons to a surrounding blanket containing fertile material where they will breed fissile material and simultaneously burn it to produce power. Since the primary function of the fusion component is to supply high energy neutrons, it can operate at or near “breakeven” condition, a much less stringent condition than that required for a pure fusion power reactor. Since the GDM is a linear, cylindrically symmetric plasma confinement device that can operate in steady state, we find it particularly suitable for utilisation as the fusion component of the proposed hybrid reactor. Moreover, a large aspect ratio GDM is desirable from the standpoint of MHD stability and that in turn allows us to treat the system as semi-infinite, and to employ two, one-dimensional equations to assess the power producing capability of the system: one that describes the time evolution of the density of uranium-233 that is being bred and burned in a thorium-232 blanket, and another that describes the transport of the 14.1 MeV neutrons generated by DT reactions in the GDM and radially impinging on the thorium blanket. We find that for a reasonable design, such a reactor can produce several gigawatts of power per cm “safely” since it will operate as a “subcritical” system. When utilised for propulsion applications we find that it can generate a specific impulse of about 17,000 seconds at a thrust of about 29 meganewtons: a propulsion capability that can readily open the Solar System to human exploration.