Assessing energy dependence of the transport of relativistic electrons in perturbed magnetic fields with orbit-following simulations
Artikel i vetenskaplig tidskrift, 2020

Experimental observations, as well as theoretical predictions, indicate that the transport of energetic electrons decreases with energy. This reduction in transport is attributed to finite orbit width (FOW) effects. Using orbit-following simulations in perturbed tokamak magnetic fields that have an ideal homogeneous stochastic layer at the edge, we quantify the energy dependence of energetic electrons transport and confirm previous theoretical estimates. However, using magnetic configurations characteristic of JET disruptions, we find no reduction in runaway electron transport at higher energies, which we attribute to the mode widths being comparable to the minor radius, making the FOW effects negligible. Instead, the presence of islands and non-uniform magnetic perturbations are found to be more important. The diffusive-advective transport coefficients calculated in this work, based on simulations for electron energies 10 keV-100 MeV, can be used in integrated disruption modelling to account for the transport due to the magnetic field perturbations.

transport

plasma disruption

stochastic magnetic field

orbit-following

runaway electrons

Författare

Konsta Särkimäki

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

Ola Embréus

Chalmers, Fysik, Subatomär fysik och plasmafysik

Eric Nardon

Le Commissariat à l’Énergie Atomique et aux Énergies Alternatives (CEA)

Tünde Fülöp

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

Nuclear Fusion

0029-5515 (ISSN) 1741-4326 (eISSN)

Vol. 60 12 126050

Ämneskategorier

Annan fysik

Fusion, plasma och rymdfysik

Den kondenserade materiens fysik

DOI

10.1088/1741-4326/abb9e9

Mer information

Senast uppdaterat

2020-12-03