Electron-Stimulated Hydrogen Desorption from Nickel and Palladium

Abstract

New experimental data are presented on the radiation-stimulated diffusion of hydrogen in metals, in particular, nickel and palladium, under the action of a 30-keV accelerated electron beam. Hydrogen desorption rates from nickel and palladium are determined for thermal and electron beam heating; a substantial shift of the thermal gas-desorption peaks to the low-temperature range is detected upon radiationinduced heating. The presence of an internal hydrogen atmosphere is shown to create favorable conditions for the vibrational-translational exchange (V–T exchange), non-equilibrium redistribution, and desorption of hydrogen from a solid upon irradiation. Accelerated hydrogen migration stimulated by electrons with an energy below the defect-formation threshold is explained at a qualitative level. First-principles calculations of the electronic structure of the metal–hydrogen system reveal that plasmons are also an efficient mechanism for radiation-energy dissipation over the whole crystal.