A model for the physical adsorption of atomic hydrogen

Abstract

The formation of the holding potential of physical adsorption is studied with a model in which a hydrogen atom interacts with a perfectly imaging substrate bounded by a sharp planar surface; the exclusion of the atomic electron from the substrate is an important boundary condition in the model. The interaction energy and the dipole and quadrupole moments of the ground state are determined with a variational calculation. The polarizability tensor of the ground state and the interaction energies in the first few excited states are also determined. A quantitative analysis is given of the transition to the dispersion-force, large-separation regime using results of perturbation theory and of the variational solution for the ground state of a hydrogen atom in the presence of a nonimaging wall. The relation of results for the image model to ideas used in the modelling of experiments is discussed; this includes a treatment of image field contributions to the depolarizing field at an ad atom.