A unified Monte Carlo interpretation of particle simulations and applications to non-neutral plasmas

Abstract

Using a ‘‘Monte Carlo interpretation’’ of particle simulations, a general description of low‐noise techniques, such as the δf method, is developed in terms well‐known Monte Carlo variance reduction methods. Some of these techniques then are applied to linear and nonlinear studies of pure electron plasmas in cylindrical geometry, with emphasis on the generation and nonlinear evolution of electron vortices. Long‐lived l=1 and l=2 vortices, and others produced by unstable diocotron modes in hollow profiles, are studied. It is shown that low‐noise techniques make it possible to follow the linear evolution and saturation of even the very weakly unstable resonant diocotron modes.