Kinetic modelling of runaway electron generation in argon-induced disruptions in ASDEX Upgrade
Artikel i vetenskaplig tidskrift, 2020

Massive material injection has been proposed as a way to mitigate the formation of a beam of relativistic runaway electrons that may result from a disruption in tokamak plasmas. In this paper we analyse runaway generation observed in eleven ASDEX Upgrade discharges where disruption was triggered using massive gas injection. We present numerical simulations in scenarios characteristic of on-axis plasma conditions, constrained by experimental observations, using a description of the runaway dynamics with a self-consistent electric field and temperature evolution in two-dimensional momentum space and zero-dimensional real space. We describe the evolution of the electron distribution function during the disruption, and show that the runaway seed generation is dominated by hot-tail in all of the simulated discharges. We reproduce the observed dependence of the current dissipation rate on the amount of injected argon during the runaway plateau phase. Our simulations also indicate that above a threshold amount of injected argon, the current density after the current quench depends strongly on the argon densities. This trend is not observed in the experiments, which suggests that effects not captured by zero-dimensional kinetic modelling - such as runaway seed transport - are also important.

fusion plasma

plasma simulation

runaway electrons

Författare

Klara Insulander Björk

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

G. Papp

Max-Planck-Gesellschaft

Ola Embréus

Chalmers, Fysik, Subatomär fysik och plasmafysik

Linnea Hesslow

Chalmers, Fysik, Subatomär fysik och plasmafysik

Tünde Fülöp

Chalmers, Fysik, Subatomär, högenergi- och plasmafysik

Oskar Vallhagen

Chalmers, Fysik, Subatomär fysik och plasmafysik

A. Lier

Max-Planck-Gesellschaft

G. Pautasso

Max-Planck-Gesellschaft

A. Bock

Max-Planck-Gesellschaft

Journal of Plasma Physics

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

Vol. 86 4 855860401

Skena och skina

Europeiska kommissionen (EU), 2015-10-01 -- 2020-09-30.

Implementation of activities described in the Roadmap to Fusion during Horizon 2020 through a Joint programme of the members of the EUROfusion consortium (EUROfusion)

Europeiska kommissionen (EU), 2014-01-01 -- 2019-01-01.

Skenande elektroner i fusionsplasmor

Vetenskapsrådet (VR), 2018-12-01 -- 2021-12-31.

Ämneskategorier

Annan fysik

Fusion, plasma och rymdfysik

Den kondenserade materiens fysik

DOI

10.1017/S0022377820000793

Mer information

Senast uppdaterat

2020-10-08