An essential result of kinetic plasma physics is the runaway phenomenon, whereby a
fraction of an electron population can be accelerated to relativistic energies. Such runaway
electrons are formed in astrophysical settings, but are also of great practical relevance to
fusion research. In the most developed fusion device, known as the tokamak, runaway
electrons have the potential to cause severe damage to the first wall. Runaway-electron
mitigation is therefore one of the critical issues in the design of a fusion power plant.

One of the problems that reactor-relevant tokamaks face are plasma terminating disruptions.
Under certain circumstances a beam of high energy electrons, so-called runaway electrons
(REs) can form, which pose serious damage to the plasma facing components. In this thesis
I numerically investigate the dynamics of REs using the relativistic, full-f, linearized kinetic
(Fokker-Planck) solver CODE (“COllisional Distribution of Electrons”) for experimentally
relevant scenarios. After a theoretical introduction into the kinetic solver applied here, I apply …