Kinetic modelling of runaway-electron dynamics

• Improved understanding of runaway-electron formation and decayprocesses are of prime interest for the safe operation of large tokamaks, and theirdynamics during dynamical scenarios such as disruptions are of particular concern. Inthis contribution, we present kinetic modelling of scenarios with time-dependent plasmaparameters – in particular, we investigate hot-tail runaway generation during a rapiddrop in plasma temperature. With the goal of studying runaway-electron generationwith a self-consistent electric field-evolution, we also discuss the implementation ofa conservative collision operator and demonstrate its properties. An operator foravalanche runaway-electron generation which includes the proper energy dependenceof the runaway distribution, is investigated, and the avalanche growth rate is shownto be significantly affected in some parameter regimes. These developments all pavethe way for an improved modelling of runaway-electron dynamics during disruptionsor other dynamic events.

Subject headings

NATURVETENSKAP  -- Fysik -- Fusion, plasma och rymdfysik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Fusion, Plasma and Space Physics (hsv//eng)

Publication and Content Type

kon (subject category)

vet (subject category)