Reaction Physics and Mission Capabilities of the Magnetically Insulated Inertial Confinement Fusion Reactor

The potential of the magnetically insulated inertia! confinement fusion (MICF) reactor as a propulsion scheme is assessed using a quasi-one-dimensional, time-dependent set of equations to describe the plasma dynamics in the system. The target in this system consists of a spherical pellet whose inner wall is coated with deuterium-tri-tium fusion fuel, and the plasma is formed as a result of wall ablation by an incident laser beam that enters the pellet through a hole. In contrast to implosion-type inertial fusion, the plasma lifetime in MICF is much longer due to the fact that it is dictated by the shock speed in the metal shell that surrounds the fuel wall rather than by the sound speed in the plasma itself. By allowing the plasma at the end of the fusion burn to adiabatically expand into an expansion chamber then exhausting it through a magnetic nozzle, we determine the propulsion capabilities of such a system. For a reasonable pellet and chamber design we find that the propulsion capability of the system will allow a round trip to Mars to be made in a relatively short time. I