Thermal accommodation of lead vapour to mica and silicon monoxide surfaces studied by a direct measurement of momentum transfer

The thermal accommodation of lead vapour atoms to mica and silicon monoxide surfaces has been studied by a direct measurement of the tangential and normal momentum transfer using a quartz torsion microbalance. The effect of the kinetic energy of incident atoms on the thermal accommodation has been investigated. For this purpose, two kinds of lead molecular beam have been used: (i) a thermal beam effused from a Knudsen crucible (kinetic energy 0.18 eV) and (ii) a fast beam produced by an ion-beam-sputtering technique (32 eV). It has been found that the thermal accommodation is complete for both kinetic energies at surface temperatures between 313K and 573K.