Isotopic mixing in hydrogen chemisorbed on polycrystalline tungsten

Abstract

Isotopic mixing of hydrogen and deuterium on a tungsten sheet has been studied through desorption spectra, in an u.h.v. system, by employing an omegatron with lanthanum hexaboride cathode. The three fundamental forms of chemisorption α, β and γ have been studied by desorption spectra of mixtures of H₂ and D₂ chemisorbed at 77, 198, 298 and 473°K. No isotopic mixing occurred in γ hydrogen, whilst a large conversion of H₂ and D₂ to HD was found in both α and β forms. Exchange between α and β, as well as between β₁ and β₂ forms was also found.