Radial Expansion of a Low Energy Positron Beam Passing Through a Cold Electron Plasma within a Uniform Magnetic Field

The radial expansion of a low energy positron beam passing through a cold electron plasma within a uniform magnetic field is studied using a classical trajectory Monte Carlo simulation. It was found that under certain conditions there is a range of impact parameters where electrons and positrons may form weakly bound states and drift perpendicular to the magnetic field before dissociating. The purpose of the simulation is to evaluate the diffusion coefficient due to the formation and dissociation of those states. In addition, the effects on the diffusion coefficient of varying the kinetic energy and the magnetic field are evaluated.