Free jet expansion of atomic beam: simulation studies of some parameters

The simulation studies of free jets are required in order to understand the physical processes occurring during expansion of an atomic beam from a high-intensity source. The atomic beam undergoes transition from the continuum regime to the non-equilibrium transition regime of flow. Various models based on continuum equations of change and the simplified Boltzmann equation are inadequate to handle the flow in the transition regime, particularly for the effect of various geometrical boundary conditions. The numerical simulation of the free jet is more suitable for these studies. In this paper we have described the development of a direct simulation Monte Carlo (DSMC) code, which was implemented on parallel processors. The model calculations have been verified with published results for simpler conditions of free jet and have also been validated with experimental results. Studies of some of the parametric studies with various source as well as substrate geometries are discussed in this paper.