Reaching Ignition in the Tokamak

During the early 1930s, the study of nuclear fusion reactions was at the forefront of high-energy physics. Fifty years later, the particle energies of interest in high-energy research have outstripped those used in controlled fusion research by about eight orders of magnitude. on the other hand, frontline magnetic-fusion devices such as the Tokamak Fusion Test Reactor at Princeton, shown in figure 1, and the Joint European Torus at Culham, England, will have luminosities of 1042 particles/cm2sec—some ten orders of magnitude beyond present-day highenergy particle colliders. these numerical contrasts serve to highlight the very different goals of high-energy physics and fusion research.