Small fusion reactors: problems, promise, and pathways

The prevalent vision of magnetic fusion as a central-station power plant projects a high-technology, low-power-density nuclear boiler that may require generally high energy costs to be economically competitive. Smaller, higher-power-density approaches can reduce the impact of the fusion power core and associated support equipment on the overall cost equation for fusion. In the course of attaining sizes and costs that are more in line with alternative energy sources a range of problems, promise, and pathways can be identified. The issues related to these more compact systems are addressed on the basis of simplified, generic reactor models