Investigation on the Propagation of the Heavy Monoatom Beam.

Abstract

In this paper, the numerical analyses on the behavior of the heavy monoatom beam are presented. Some numerical methods for the analysis of rarefied flow have been proposed so far, which have been successful as applied to the flow Kn<1 such as in the semiconductor manufacturing processes and other vacuum technologies. However, since the atomic number density of the beam is extremely low, the flow is categorized as the molecular flow (kn>1) in which the molecular free path is rather large compared with the representative scale of the beam. Hence the probability density function of the atomic free path in the nonequilibrium field was considered in the numerical simulation of the beam propagation. Consequently, the calculated results on the beam diffusion due to mutual atomic scattering agreed well with the measured data by means of the gadolinium vapor.