Gyrokinetic simulations of neoclassical transport using a minimal collision operator

Abstract : Conventional neoclassical predictions are successfully recovered within a gyrokinetic framework using a minimal Fokker–Planck collision operator. This operator is shown to accurately describe some essential features of neoclassical theory, namely the neoclassical transport, the poloidal rotation and the linear damping of axisymmetric flows while interestingly preserving a high numerical efficiency. Its form makes it especially adapted to Eulerian or Semi–Lagrangian schemes.