Magnetic Confinement Fusion

Fusion plasmas with reactorlike temperatures have been confined in magnetic-field configurations of the tokamak type. The measured rate of heat leakage from these plasmas is sufficiently small to be compatible with the requirements of a full-sized fusion power reactor. Improvements in other aspects of reactor performance are still needed, however, and the high cost of reactor- development steps has become an obstacle on the path to practical fusion power.