Spatiotemporal analysis of the runaway distribution function from synchrotron images in an ASDEX Upgrade disruption
Artikel i vetenskaplig tidskrift, 2021

Synchrotron radiation images from runaway electrons (REs) in an ASDEX Upgrade discharge disrupted by argon injection are analysed using the synchrotron diagnostic tool Soft and coupled fluid-kinetic simulations. We show that the evolution of the runaway distribution is well described by an initial hot-tail seed population, which is accelerated to energies between 25-50 MeV during the current quench, together with an avalanche runaway tail which has an exponentially decreasing energy spectrum. We find that, although the avalanche component carries the vast majority of the current, it is the high-energy seed remnant that dominates synchrotron emission. With insights from the fluid-kinetic simulations, an analytic model for the evolution of the runaway seed component is developed and used to reconstruct the radial density profile of the RE beam. The analysis shows that the observed change of the synchrotron pattern from circular to crescent shape is caused by a rapid redistribution of the radial profile of the runaway density.

runaway electrons

fusion plasma

Författare

Mathias Hoppe

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

Linnea Hesslow

Chalmers, Fysik, Subatomär fysik och plasmafysik

Ola Embréus

Chalmers, Fysik, Subatomär fysik och plasmafysik

Lucas Unnerfelt

Chalmers, Fysik, Subatomär fysik och plasmafysik

Gergely Papp

Max-Planck-Gesellschaft

Istvan Pusztai

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

Tünde Fülöp

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

Olle Lexell

Chalmers, Fysik, Subatomär fysik och plasmafysik

T. Lunt

Max-Planck-Gesellschaft

E. Macusova

Czech Academy of Sciences

P. McCarthy

University College Cork

G Pautasso

Max-Planck-Gesellschaft

G.I. Pokol

Budapesti Muszaki es Gazdasagtudomanyi Egyetem

Gábor Pór

Budapesti Muszaki es Gazdasagtudomanyi Egyetem

Pontus Svensson

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

Journal of Plasma Physics

0022-3778 (ISSN) 1469-7807 (eISSN)

Vol. 87 1 855870102

Ämneskategorier

Acceleratorfysik och instrumentering

Astronomi, astrofysik och kosmologi

Fusion, plasma och rymdfysik

DOI

10.1017/S002237782000152X

Mer information

Senast uppdaterat

2021-02-08