Computational investigation of plasma-wall interaction issues in magnetized target fusion

Abstract

In the concept known as magnetized target fusion (MTF) in the United States and magnitnoye obzhatiye (MAGO) in Russia, a preheated and magnetized target plasma is hydrodynamically compressed to fusion conditions. Because the magnetic field suppresses losses by electron thermal conduction in the fuel during the target implosion heating process, the implosion velocity may be much smaller than in traditional inertial fusion. Hence magnetically driven using relatively inexpensive electrical pulsed power, may be practical. The relatively dense, hot target plasma, with starting conditions O(10/sup 18/ cm/sup -3/, 100 eV, 100 kG), may spend 10 or more microseconds in contact with a metal wall during formation and compression. Influx of a significant amount of high-Z wall material during this time could lead to excessive cooling by dilution and radiation that would prevent the desired near-adiabatic compression heating of the plasma to fusion conditions. Magnetohydrodynamic (MHD) calculations including detailed effects of radiation, heat conduction, and resistive field diffusion are being done, using several different computer codes, to investigate such plasma-wall interaction issues in ongoing MTF target plasma experiments and in proposed liner-on-plasma MTF experiments.