title: Desorption of H2, HD, and D2 through temporary negative ion formation.
abstract: Physically adsorbed H(2), HD, and D(2) desorbs via the low-energy 2Σ(u)+ electron scattering resonance with characteristic electron energy dependent cross sections as we show by desorption and electron energy-loss measurements. Only H(2) and HD desorb, for energetic reasons, via excitation of the j = 0 → 2 rotational mode and its subsequent decay into free translational motion, while all three isotopes desorb by direct transitions to unbound continuum states, with a probability close to unity and an unexpectedly weak mass dependence ~m(-1/2).
authors.affiliation: Department of Physics and Electrical Engineering, Karlstad University, SE-651 88 Karlstad, Sweden.
authors.forename: K
authors.initials: K
authors.lastname: Svensson
authors.forename: S
authors.initials: S
authors.lastname: Andersson