Fusion Reaction Product Transport for Magnetized Target Fusion

Abstract

This paper deals with magnetized target fusion (MTF), which proposes to use a magnetic field to reduce the electron thermal conduction and to enhance energy deposition by the charged fusion products. Here we discuss two important aspects of charged particle interaction with the magnetized plasma: 1) the effect of the magnetic field on the stopping power of the plasma and 2) increased charged particle path length within the fusion fuel due to the contortion of the path by the field. The effect of the field on the stopping power depends on the ratios of several plasma parameters, including the Debye length, the Larmor radius, and the relative values of plasma, cyclotron, and collision frequencies. For the MTF regime these parameters are linked due to the need to have adequately magnetized plasma for the reduction of electron thermal conductivity and the need for adequately reduced density to insure that the radiation from the plasma is not too high. We use partially analytic results to show how field gradients shrink the size of the fusion ignition region in the Lindl-Widner diagrams.