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.

Plasma confinement

Fusion plasma

Plasma flows

Författare

Sarah Newton

Culham Lab

Chalmers, Fysik, Subatomär fysik och plasmafysik

Per Helander

Max-Planck-Gesellschaft

Albert Mollén

Max-Planck-Gesellschaft

Håkan Smith

Max-Planck-Gesellschaft

Journal of Plasma Physics

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

Vol. 83 5 905830505

Ämneskategorier

Energiteknik

Fusion, plasma och rymdfysik

Den kondenserade materiens fysik

DOI

10.1017/s0022377817000745

Mer information

Senast uppdaterat

2020-01-20