Measurement of lifetimes and binding energies of atoms adsorbed on surfaces at low temperatures by a rapid-flash-desorption technique

A dynamic method for measuring the characteristic lifetimes and binding energies of physisorbed atoms is described and results presented. We find for ∼1.5 monolayers of helium adsorbed on Constantan an isosteric binding energy of 31 ± 1°K and a characteristic lifetime of (2 ± 0.5) × 10-7 sec. The velocity distribution of the desorbing atoms is found to be non-Maxwellian.