Generation of runaway electrons during the initial stage of the T-10 tokamak plasma discharge

Abstract

The formation of runaway electron beams in the initial stage of discharge is one of the characteristic features of fusion facilities with magnetic plasma confinement, such as tokamaks. They are generated due to the presence of the high electric fields and strong plasma-wall interaction in plasma. The runaway electrons produced during the breakdown stage also remain in the plasma in the quasistationary stage of the discharge. Studies carried out at the T-10 tokamak show that the electron energy and the heat flux density can reach 5–10 MeV and 1–3 GW/m2, respectively. Thus, the interaction with electrons causes erosion and damage to the limiter surface. In this article, the energy distribution of high-energy electrons formed in the initial stage of plasma discharge in the T-10 tokamak during the formation of runaway electron beams in a strong longitudinal magnetic field was studied. The effect of the plasma density and MHD perturbations on the generation and acceleration of runaway electrons was revealed. The energy distributions of runaway electrons were estimated for different stages of the plasma discharge development.