Some interesting aspects of physisorption stay-time measurements obtained using molecular-beam techniques

Stay-time distributions have been obtained for Xe physisorbing on polycrystalline nickel as a function of the target temperature using a pulsed molecular-beam technique. Some interesting effects due to ion bombardment of the surface using He, Ar, and Xe ions are presented. Measured detector signal shapes are found to deviate from those predicted for first-order desorption with velocities corresponding to Maxwellian effusion at the surface temperature. Evidence is found for interaction between beam pulse adsorption and steady-state adsorption of beam species background atoms.