Energy gains of a wall-confined fusion cycle

Abstract

Calculations of energy gain are made for a wall‐confined deuterium–tritium fusion cycle. Plasma, first heated by strong shock waves, re‐expands to completely fill a cylindrical cavity. An azimuthal magnetic field, everywhere parallel to the walls, provides thermal insulation. The energy input is evaluated by solving the transverse magnetohydrodynamic shock wave equations. The fusion energy yield is determined by the competition between fusion burn, radiation, and wall cooling. A one‐dimensional initial value code is used to evaluate the plasma energy loss rates and the fusion burn. Two‐dimensional loss mechanisms are estimated using a modified form of the one‐dimensional model. Energy gain ratios of twenty are calculated for a cylinder whose characteristic size L is less than one meter. Energy breakeven is found for L∼0.2 m, with an energy input of 1.9 MJ at a power of 8.8 TW.