NORSE: A solver for the relativistic non-linear Fokker-Planck equation for electrons in a homogeneous plasma

Journal article, 2017

Energetic electrons are of interest in many types of plasmas, howe ver previous modelling of their properties have been restricted to the use of linear Fokker-Planck collision ope rators or non-relativistic formulations. Here, we describe a fully non-linear kinetic-equation solver, capable of handling large electric-field strengths (compared to the Dreicer field) and relativistic temperatures. This tool allows modelling of the momentum- space dynamics of the electrons in cases where strong departure s from Maxwellian distributions may arise. As an example, we consider electron runaway in magnetic-confinement fusion plasmas and describe a transition to electron slide-away at field strengths significantly lower than pre viously predicted.