Implementation and verification of a model linearized multi-species collision operator in the COGENT code

Abstract

We implement the multi-species linearized model collision operator, based on the approach proposed by Kolesnikov [1], in the full-f continuum gyrokinetic code COGENT [2]. We describe the operator and use it in several COGENT simulations of highly collisional plasmas. We analyze simulation results with the Braginskii fluid model [3] to illustrate that COGENT recovers both friction and thermal forces. Finally, we simulate the neoclassical transport of heavy impurities with COGENT and illustrate agreement with previously published [4] theoretical results.