CURRENT-DENSITY ENHANCEMENTS OF THE HIGHEST-T-C SUPERCONDUCTORS WITH GEV PROTONS

In several T1- and Hg-based high-T-c superconducting materials, vortex -pinning defects were formed by irradiation with 0.8 GeV protons. The protons cause heavy constituent nuclei (Tl, Hg, Bi,...) to fission, wh ich generates randomly oriented tracks. These columnar defects lead to significant enhancements in the current-conducting properties. We inv estigated bulk materials and thin films, irradiated with or without Pb or Au ''amplifier foil'' overlayers, which increase the number of col umn-creating fission fragments. (C) 1997 American Institute of Physics .