Electromagnetic Continuum Gyrokinetic Turbulence Simulations in the Tokamak Edge

Gkeyll, a full-F continuum gyrokinetic code, is being developed to study turbulence in the edge region of fusion devices. The edge region involves large-amplitude fluctuations, electromagnetic effects, and plasma interactions with material walls, making it more computationally challenging than the core region. Gkeyll models the turbulence by solving the 5-D full-F gyrokinetic system in Hamiltonian form using an energy conserving high-order discontinuous Galerkin scheme. We present an extension of the scheme to include self-consistent electromagnetic perturbations that maintains the energy conservation properties of the scheme. We describe our choice of the symplectic (v_||) formulation of electromagnetic gyrokinetics instead of the Hamiltonian (p_||) formulation. We discuss how our scheme avoids the Ampere cancellation problem. We present some preliminary electromagnetic turbulence results.