The retention of 100 eV tritium in tungsten and tungsten doped with 1% lanthanum oxide

Tungsten is 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 tungsten and tungsten doped with 1% lanthanum oxide exposed to high fluxes of 100 eV tritons. Measurements were performed over the temperature range of 423 to 973 K. 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 was seen to peak at intermediate temperatures (700 K) with very low retention values at both high and low temperatures. Modeling was performed on the retention as a function of temperature and the outgassing characteristics. (author)