Recent Advances on the Spherical Tokamak Route to Fusion Power

Stambaugh developed the Peng-Hicks concept of a fusion reactor based on a solid copper center-post spherical tokamak (ST). Using the promising results from the START experiment, they produced a vision for a path to fusion power. This path had two elements such as the ability to produce high fusion gain from an ST and of equal importance, the ability to demonstrate this in a small (and therefore relatively low cost) pilot plant device. In this paper, we review various attempts to pursue this vision, and try to elucidate the reason why success has not yet been achieved. However, we show that the advent of high temperature superconductors may overcome some of the problems, and we suggest a revised version of the small, low entry cost route to fusion power.