Issues for magnetic and inertial fusion energy development

Abstract

A discussion of the issues facing both magnetic and inertial fusion schemes for the generation of energy is presented. For magnetic fusion, the conventional tokamak device appears likely to 'work', i.e. it will convert wall plug power into plasma temperature and reasonable energy gain will be obtained. However, it is viewed by many as unacceptable as a commercial reactor candidate-i.e. it is too expensive and too complex. Arguing that within a given concept (but not between concepts) compactness is advantageous, a steady-state energy balance model is used to illustrate how to reduce size. Inertial fusion offers potential advantages over its magnetic counterpart, but while physics progress has been maintained, hot-spot ignition and propagating burn remain to be demonstrated in the laboratory. The proposed solutions to inertial fusion technology challenges, mostly very different from those involved in magnetic fusion, also require demonstrating.

Particle confinement and transport in JT-60U

“…The values of α and β indicate the dependence on the particle source distribution and the core confinement. The decrease in τ R p with increasing ne reflects the localization of the particle source in the edge region including the divertor and SOL with increasing ne [17]. The increase in τ NB p with ne reflects the characteristics of plasma core confinement, because the change of the particle source distribution with increasing ne is small.…”