Velocity space ring‐plasma instability, magnetized, Part II: Simulation

The ring‐plasma instability arising due to two‐energy component ions of a homogeneous plasma in a uniform magnetic field is studied through use of electrostatic and electromagnetic simulations, treating the ring ions as particles and the target plasma (ions and electrons) as linearized fluids. Simulation results verify very closely the predictions of the linear Vlasov theory and provide extensive information on nonlinear features such as beam spreading, slowing down, and saturation, some of which are in agreement with analytic explanations. This nonlinear evolution occurs before Coulomb collisions take place, and may be considered as the initial condition for Fokker–Planck calculations. The justification for using a linearized fluid is also discussed.