Runaway dynamics in the DT phase of ITER operations in the presence of massive material injection
Journal article, 2020

A runaway avalanche can result in a conversion of the initial plasma current into a relativistic electron beam in high-current tokamak disruptions. We investigate the effect of massive material injection of deuterium-noble gas mixtures on the coupled dynamics of runaway generation, resistive diffusion of the electric field and temperature evolution during disruptions in the deuterium-tritium phase of ITER operations. We explore the dynamics over a wide range of injected concentrations and find substantial runaway currents, unless the current quench time is intolerably long. The reason is that the cooling associated with the injected material leads to high induced electric fields that, in combination with a significant recombination of hydrogen isotopes, leads to a large avalanche generation. Balancing Ohmic heating and radiation losses provides qualitative insights into the dynamics; however, an accurate modelling of the temperature evolution based on energy balance appears crucial for quantitative predictions.

fusion plasma

runaway electrons

Author

Oskar Vallhagen

Chalmers, Physics, Subatomic and Plasma Physics

Ola Embréus

Chalmers, Physics, Subatomic and Plasma Physics

Istvan Pusztai

Chalmers, Physics, Subatomic, High Energy and Plasma Physics

Linnea Hesslow

Chalmers, Physics, Subatomic and Plasma Physics

Tünde Fülöp

Chalmers, Physics, Subatomic, High Energy and Plasma Physics

Journal of Plasma Physics

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

Vol. 86 4 475860401

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

European Commission (EC), 2014-01-01 -- 2019-01-01.

Running away and radiating (PLASMA)

European Commission (EC), 2015-10-01 -- 2020-09-30.

Runaway electrons in fusion plasmas

Swedish Research Council (VR), 2018-12-01 -- 2021-12-31.

Subject Categories

Other Physics Topics

Fusion, Plasma and Space Physics

Condensed Matter Physics

DOI

10.1017/S0022377820000859

More information

Latest update

2/4/2021 2