FIELD-REVERSED MIRROR REACTOR

Abstract

We have completed the conceptual design of a fusion power reactor based on the field-reversed mirror confinement concept. A number of possible plasma start-up scenarios were considered, but the choice of a specific method for the conceptual design was deferred, pending experimental demonstration of one or more of the schemes in a mirror machine. So far, attempts to create field reversal by neutral beam injection in 2XIIB have been unsuccessful although they have come very close. A new approach being pursued is to use a coaxial plasma gun to create a target plasma in which field reversal already exists. Basic to our reactor plasma model is the assumption that, once created, the plasma can be stably maintained by injection of a neutral beam current sufficient to balance the particle loss rate. Two additional assumptions are that the particle confinement time is proportional to the ion-ion collision time and that the size of the field-reversed plasma, measured by the ratio of minor radius to ion gyroradius is limited by stability to about 5. A result of this latter assumption is that field-reversed plasma layers are predicted to be quite small, producing tens of MW of fusion power. Our parameter studies indicate that larger radii plasma would greatly improve the reactor economics.