Impurity transport and bulk ion flow in a mixed collisionality stellarator plasma
Artikel i vetenskaplig tidskrift, 2017

The accumulation of impurities in the core of magnetically confined plasmas, resulting from standard collisional transport mechanisms, is a known threat to their performance as fusion energy sources. Whilst the axisymmetric tokamak systems have been shown to benefit from the effect of temperature screening, that is an outward flux of impurities driven by the temperature gradient, impurity accumulation in stellarators was thought to be inevitable, driven robustly by the inward pointing electric field characteristic of hot fusion plasmas. We have shown in Helander et al. (Phys. Rev. Lett., vol. 118, 2017a, 155002) that such screening can in principle also appear in stellarators, in the experimentally relevant mixed collisionality regime, where a highly collisional impurity species is present in a low collisionality bulk plasma. Details of the analytic calculation are presented here, along with the effect of the impurity on the bulk ion flow, which will ultimately affect the bulk contribution to the bootstrap current.

fusion plasma

plasma flows

plasma confinement

Författare

Sarah Newton

Chalmers, Fysik, Subatomär fysik och plasmafysik

P. Helander

Journal of Plasma Physics

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

Vol. 83

Ämneskategorier

Fusion, plasma och rymdfysik

DOI

10.1017/s0022377817000745

Mer information

Skapat

2017-11-22