Thermonuclear self-sufficiency in the R < 2 range

Since fusion reactor gain will probably remain in the R < 2 range, for the near term, it may be useful to analyze the plant parameters that would permit the system to be self-sufficient, i.e., to operate above the break-even curve. This paper presents a five-zones Lawson diagram to determine successive working stages of thermonuclear plants. A general power flow diagram is shown in order to estimate partial and global plant efficiencies, for present and future technology, which are finally compared to those required by the Lawson condition for break-even. It is concluded that, by the inclusion of a magnetic conversion system and the improvement of partial efficiencies, it will be possible to obtain a global efficiency of 0.5 that would permit self-sufficiency in the R ∼1 range