Effect of partially ionized impurities and radiation on the effective critical electric field for runaway generation
Artikel i vetenskaplig tidskrift, 2018

We derive a formula for the effective critical electric field for runaway generation and decay that accounts for the presence of partially ionized impurities in combination with synchrotron and bremsstrahlung radiation losses. We show that the effective critical field is drastically larger than the classical Connor-Hastie field, and even exceeds the value obtained by replacing the free electron density by the total electron density (including both free and bound electrons). Using a kinetic equation solver with an inductive electric field, we show that the runaway current decay after an impurity injection is expected to be linear in time and proportional to the effective critical electric field in highly inductive tokamak devices. This is relevant for the efficacy of mitigation strategies for runaway electrons since it reduces the required amount of injected impurities to achieve a certain current decay rate.

runaway electron

Fokker-Planck

disruption

tokamak

Författare

Linnea Hesslow

Chalmers, Fysik, Subatomär fysik och plasmafysik

Ola Embréus

Chalmers, Fysik, Subatomär fysik och plasmafysik

George Wilkie

Chalmers, Fysik, Subatomär fysik och plasmafysik

Gergely Papp

Max Planck-institutet

Tünde Fülöp

Chalmers, Fysik, Subatomär fysik och plasmafysik

Plasma Physics and Controlled Fusion

0741-3335 (ISSN) 1361-6587 (eISSN)

Vol. 60 7 074010

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.

Skena och skina

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

Ämneskategorier

Acceleratorfysik och instrumentering

Fusion, plasma och rymdfysik

Annan elektroteknik och elektronik

DOI

10.1088/1361-6587/aac33e