Effects of plasma density and toroidal magnetic field on lower hybrid current drive efficiency on HT-7 Tokamak

Citation
Bj. Ding et al., Effects of plasma density and toroidal magnetic field on lower hybrid current drive efficiency on HT-7 Tokamak, CHIN PHYS L, 17(7), 2000, pp. 519-521
Citations number
7
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
CHINESE PHYSICS LETTERS
ISSN journal
0256-307X → ACNP
Volume
17
Issue
7
Year of publication
2000
Pages
519 - 521
Database
ISI
SICI code
0256-307X(2000)17:7<519:EOPDAT>2.0.ZU;2-N
Abstract
Lower hybrid current drive experiments on the HT-7 device have been carried out by scanning the following parameters: central line averaged electron d ensity (n(e) = 0.6 - 2.0 x 10(19) m(-3)) and toroidal magnetic field (B-t 1 .62 - 2.0 T). The dependence of current drive efficiency on these parameter s has been studied and the experimental curves of current drive efficiency as a function of n(e) and B-t have also been obtained. From these experimen tal results, it can be seen that current drive efficiency rises with the in crease of toroidal magnetic field. As plasma density increases, the current drive efficiency first increases to a certain value, then gradually decrea ses, that is, there exists an optimized density regime where a better drive efficiency can be obtained. The analysis shows that the current drive effi ciency is mainly affected by wave accessibility and impurity concentration, and the competition of these two factors determines the current drive effi ciency.