Helium release from aged palladium tritide

Abstract

Experimental studies of helium release from aged ${\mathrm{PdT}}_{\mathrm{x}}$ show that the helium-to-metal-atom ratio saturates at a value of [He]/[Pd]\ensuremath{\simeq}0.5 under conditions of ambient-temperature storage. Below this value, very little helium release occurs. Thermal desorption experiments show that release from a sample with [He]/[Pd]\ensuremath{\simeq}0.3 requires temperatures in excess of \ensuremath{\sim}600 K, while release from a sample with [He]/[Pd]\ensuremath{\simeq}0.02 requires temperatures in excess of at least 1300 K. These results are related to the question of the disposition of helium that would be produced by hypothetical fusion reactions in a ${\mathrm{PdD}}_{\mathrm{x}}$ electrode.