Radiation damage and stress effects in superconductors: materials for high-field applications

Many factors are involved in the choice of materials for magnets to be used in fusion devices employing magnetic confinement. In order to develop a complete understanding of the magnet's operating characteristics, synergistic effects such as the influence of radiation effects on the stress/strain behavior, and vice versa, needs study. We limit our discussion to two superconductors: NbTi and the A15 compounds. The response of NbTi to both irradiation and stress is treated. We are concerned with the same effects in the A15's, focusing our attention there on the prime candidate material, Nb3Sn. The discussion of these effects includes the microscopic physical mechanisms which couple the change in state of the superconducting material to the change in critical properties. (Auth.)