IMPLICIT-MOMENT, PARTIALLY LINEARIZED PARTICLE SIMULATION OF KINETIC PLASMA PHENOMENA

An algorithm for kinetic simulation of electron and ion plasmas is int roduced that combines both implicit and perturbative methods to deal e fficiently with disparate time scales and signal-to-noise issues assoc iated with particle discreteness. The algorithm is introduced for an e lectrostatic model in a strong magnetic field with gyrokinetic ions an d drift-kinetic electrons. Some of the numerical dispersion properties are analyzed and confirmed in test simulations. Two-dimensional appli cations of the algorithm to drift-wave instabilities excited either by an ion temperature gradient (ion-temperature-gradient instability) or by electron inverse Landau damping in the presence of a density gradi ent (collisionless drift instability) are presented that illustrate th e usefulness of the method. Clear gains in resolution and computationa l efficiency over previous methods are achieved.