Quasi-linear analysis of the extraordinary electron wave destabilized by runaway electrons

Abstract

Runaway electrons with strongly anisotropic distributions present in post-disruption tokamak plasmas can destabilize the extraordinary electron (EXEL) wave. The present work investigates the dynamics of the quasi-linear evolution of the EXEL instability for a range of different plasma parameters using a model runaway distribution function valid for highly relativistic runaway electron beams produced primarily by the avalanche process. Simulations show a rapid pitch-angle scattering of the runaway electrons in the high energy tail on the $100-1000\mu \mathrm{s}$ time scale. Due to the wave-particle interaction, a modification to the synchrotron radiation spectrum emitted by the runaway electron population is foreseen, exposing a possible experimental detection method for such an interaction.

References in corpus (3)

• Numerical calculation of the runaway electron distribution function and associated synchrotron emission
• Synchrotron radiation from a runaway electron distribution in tokamaks
• Electromagnetic waves destabilized by runaway electrons in near-critical electric fields

Cited by in corpus (7)

• Role of kinetic instability in runaway electron avalanche and elevated critical electric fields
• Effect of partially ionized impurities and radiation on the effective critical electric field for runaway generation
• NORSE: A solver for the relativistic non-linear Fokker-Planck equation for electrons in a homogeneous plasma
• Alpha particle driven Alfvénic instabilities in ITER post-disruption plasmas
• Numerical calculation of ion runaway distributions
• The impact of fusion-born alpha particles on runaway electron dynamics in ITER disruptions
• Bump formation in the runaway electron tail