Retention of 100 eV Tritium in Tungsten at High Fluxes

Abstract

Tungsten ideally suited for many fusion applications due to its high threshold for sputtering as well as its very high melting point. If tungsten is to be used as a plasma-facing material in a fusion reactor, it is necessary to know its hydrogen isotope recycling and retention characteristics. The Tritium Plasma Experiment (TPE) has been used in a research program to determine the retention of tritium in 99.95% pure tungsten exposed to high fluxes of 100 eV tritons. Plasma exposures were performed at a temperature of 623 °K. The flux of ions ranged from 1021 to 1022 ions/m2/sec. After exposure to the tritium plasma, the samples were transferred to an outgassing system containing an ionization chamber for detection of the released tritium. The retention results closely followed a power law. Modeling was performed on the retention as a function of flux and the outgassing characteristics.