Release Time:2019-03-11  Hits:

Indexed by: Journal Article

Date of Publication: 2017-11-01

Journal: NUCLEAR FUSION

Included Journals: EI、SCIE、Scopus

Volume: 57

Issue: 11

ISSN: 0029-5515

Key Words: drift E x B; in-out asymmetry; carbon impurity

Abstract: The role of the E x B electric drift on background plasma and carbon impurity in-out divertor asymmetry was estimated under L-mode and H-mode conditions in the high recycling regime and partial detachment regime by using the edge plasma code SOLPS5.1. It was found that the poloidal electric drift E-r x B also may play a dominant role during H-mode discharge in high recycling regime, instead of the radial electric drift E-theta x B. Moreover, it also was found that during H-mode with partial detachment both components can play simultaneously a crucial role in inducing the in-out asymmetry. Their synergistic effect can make the asymmetry much more obvious than that with either of them separately. However, E-theta x B in partial detachment during L-mode can play a main role in inducing in-out asymmetry, rather than E-r x B. Besides, the role of E x B components on carbon (C) impurity in-out asymmetry was also addressed. Simulation results reveal that E-r x B or E-theta x B individually have a very small effect on C impurity ions in-out asymmetry, especially E-theta x B, while their synergistic effect makes the impurity ions exhibit a much more remarkable in-out asymmetry. Moreover, it was found that the E-r x B and E-theta x B drift flows in the private flux region could play a crucial role in inducing C impurity in-out asymmetry, rather than the parallel flow or electric drift flow in the upstream SOL region when only considering E x B.