An orbit averaged particle code

A new method for efficient computer simulation of long time-scale plasma physics phenomena is proposed which has proved successful in one- and two-dimensional magneto-inductive particle codes. The method relies on orbit-averaging charge and current densities in Maxwell's equations before solving for the self-consistent electric and magnetic fields in order to filter out unwanted high-frequency oscillations and reduce the number of simulation particles necessary to fill phase space adequately. This method offers the potential of greatly improving the economics of simulating the evolution of a plasma over time intervals which are long compared to particle orbit periods. A particular scheme using a predictor-corrector iterative method and time splitting is discussed, which is both stable and accurate. Application to the efficient simulation of a magnetic mirror machine plasma injected with energetic neutral beams is presented.