Test Particle Calculation of Plasma Equilibria

We present a numerical technique for self-consistently calculating plasma equilibria with prescribed sources and sinks on the boundaries, i.e. a scattering system. The method is applied to the earth’smagnetotail. The method follows individual particles through a prescribed magnetic field, while calculating the density, current and pressure that the particle contributes on a uniformly spaced grid. The individual particles are weighted to model a given source distribution and the total equilibrium properties, including the resulting magnetic field, are evaluated. The calculated and prescribed magnetic fields are then compared. If the fields differ significantly, the two fields are mixed and the process repeated. Convergence to the self-consistent field typically takes between 100 and 150 iterations.