Dynamics of tokamak plasma experiments and reactors

Abstract

At the present state of knowledge, the design of fusion reactors is based on scaling which has not been fully verified experimentally. Various choices of scaling laws can be made, leading to different results. Design studies demonstrate sensitivity to the scaling laws assumed. Models are described suitable for simulating the energy and particle balances of a tokamak plasma, for surveying the range of parameters possible during operation, and for surveying the sensitivities of the parameters to system changes. Physical models for transport losses, beam-plasma interactions, noncircular plasma behavior, sputtering, impurity effects, and reactor control are included. The calculations based on these models are tested against present experimental results and are used to predict the behavior of future devices. Power balance results and their sensitivities are focused primarily on the ORNL Experimental Power Reactor (EPR), Demonstration Power Reactor (Demo), and Commercial Power Reactor (CPR) Designs. The sizes of these plants and the ranges of their possible power outputs are discussed. The limitations on the operation of these devices due to constraints such as beta limits, sputtering, and impurity buildup are described. Conclusions which result from applying the model to the systems noted above, but which are applicable to tokamak design in general, are presented.