On the role of numerical dissipation in gyrokinetic Vlasov simulations of plasma microturbulence

Non-physical effects of discretization schemes on simulations of plasma microturbulence are investigated, and different types of hyperdiffusion terms in the gyrokinetic Vlasov equation are employed to cancel or mitigate these effects. Widely applicable rules on how to operate parallel spatial and velocity space diffusion – to avoid numerically excited high-k∥k∥ modes and recurrence phenomena, respectively – are presented. The impact of diffusion terms on and the applicability of these findings to results obtained in the context of a benchmark scenario are demonstrated.