Lower hybrid current drive experiments and improved performance on the HT-7 superconducting tokamak

Citation
Gl. Kuang et al., Lower hybrid current drive experiments and improved performance on the HT-7 superconducting tokamak, NUCL FUSION, 39(11Y), 1999, pp. 1769-1774
Citations number
10
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Physics
Journal title
NUCLEAR FUSION
ISSN journal
0029-5515 → ACNP
Volume
39
Issue
11Y
Year of publication
1999
Pages
1769 - 1774
Database
ISI
SICI code
0029-5515(199911)39:11Y<1769:LHCDEA>2.0.ZU;2-R
Abstract
The feedback control system to control plasma current and position on the H T-7 superconducting tokamak was greatly improved in early 1998. Lower hybri d current drive (LHCD) experiments with the improved control system were pe rformed to sustain long pulse discharges and to improve plasma confinement. Partial non-inductive current drive and full non-inductive current drive f or several seconds by means of LHCD were demonstrated. It was observed that plasma confinement could be considerably improved by LHCD. Experimental ev idence suggests that this improvement during the LHCD phase could be due to the modification of the current profile in the outer region of the plasma. MHD modes (especially m = 2) seem unstable with such a current profile. Th e EFIT code was modified for the reconstruction of the magnetic surfaces in HT-7 and a test computation was performed.