High-density, low-q discharges with D-shaped and circular cross-sections in Doublet III

The maximum plasma current in Doublet III is found to be limited by disruptions when the limiter safety factor is approximately two. However, because of the strong toroidal and shaping-field effects on the rotational transform at the outer plasma edge associated with a vertical elongation of 1.5 D-s...

Full description

Saved in:
Bibliographic Details
Published in:Nuclear fusion 1982-01, Vol.22 (3), p.409-421
Main Authors: Nagami, M, Yoshida, H, Shinya, K, Jahns, G.L, Yokomizo, H, Shimada, M, Ioki, K, Izumi, S, Kitsunezaki, A
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The maximum plasma current in Doublet III is found to be limited by disruptions when the limiter safety factor is approximately two. However, because of the strong toroidal and shaping-field effects on the rotational transform at the outer plasma edge associated with a vertical elongation of 1.5 D-shape, the safety factor q*@da estimated from simple geometric considerations for D-shaped plasmas corresponds to values as low as 1.5. These discharges operate stably with considerably higher plasma current than most reactor design studies assume. These low-q discharges show excellent plasma performance: very flat spatial electron temperature profiles, high-density operation with n@u- sub(e)R/B sub(T) up to 7.8, and good energy confinement producing a volume-average beta of up to 1% with Ohmic heating only. This operational regime appears to be applicable to future high- beta tokamaks with D-shaped cross-sections.
ISSN:0029-5515
1741-4326
DOI:10.1088/0029-5515/22/3/009