Joint US/Russian plasma formation experiments for magnetic compression/magnetized target fusion (MAGO/MTF)

摘要

Magnetic Compression/Magnetized Target Fusion (MAGO/MTF) is an area of fusion research that is intermediate between Magnetic Fusion Energy (MFE) and Inertial Confinement Fusion (ICF) in time and density scales. This concept has been pursued independently in Russia as MAGO (MAGnitnoye Obzhatiye, or magnetic compression) and in the US. MAGO/MTF uses a pusher-confined, magnetized, preheated plasma fuel within a fusion target. The magnetic field suppresses losses by electron thermal conduction in the fuel during the target implosion heating process. Reduced losses permit adiabatic compression of the fuel to ignition temperatures even at low (e.g., 1 cm/(micro)s) implosion velocities. In MAGO/MTF, the convergence ratio of the pusher in quasi-spherical geometries may potentially be less than 10, depending upon the initial temperature of the fuel and the adiabaticity of the implosion. Previous work relevant to MAGO/MTF includes, but is not limited to, work in imploding liner fusion, impact fusion and electron-beam driven ''phi'' targets. MAGO/MTF has not been extensively pursued, in part because of the challenges associated with developing and mating the two elements of an MTF system: (a) a target implosion system (b) a means of preheating and magnetizing the thermonuclear fuel prior to implosion. In this paper the authors report the results of experiments exploring a scheme for forming a hot, magnetized plasma possibly suited for subsequent implosion in a MAGO/MTF context. The experiment described here used a plasma formation chamber. The outer radius of the plasma volume was 10 cm. The chamber was initially filled with 10 Torr of 50% deuterium, 50% tritium gas seeded with 0.01% neon. The chamber behavior was computationally modeled using two-dimensional magnetohydrodynamic techniques.