Back to Search Start Over

Plasma rotation and the radial electric field during off-axis NBI in the DIII - D tokamak

Authors :
K. H. Burrell
T.H. Osborne
P. Gohil
A. B. Hassam
Source :
Plasma Physics and Controlled Fusion. 38:1243-1247
Publication Year :
1996
Publisher :
IOP Publishing, 1996.

Abstract

Experiments have been carried out on the DIII-D tokamak to investigate whether off-axis NBI can: (a) drive significant perpendicular flow to lead to increased suppression of turbulence and improved confinement, and (b) be used to control the radial electric field profile. Measurements of both impurity ion poloidal and toroidal rotation profiles were made using charge exchange recombination spectroscopy. These experiments used a low current, low elongation (I{sub p} = 0.5 MA, {kappa} = 1.2) plasma whose magnetic axis was shifted 36 cm vertically upward from the vessel midplane and then shifted downward to be centered on the midplane later in the discharge. 10.7 MW of beam power was applied to maximize NBI effect while operating at low target densities and high temperature to minimize poloidal damping. Results from these experiments show a slight increase in impurity ion poloidal rotation velocity during the vertical shifted phase of off-axis NBI discharge. The toroidal rotation profile is more peaked during off-axis NBI. Both these effects lead to a change in the V x B contribution to the radial electric field during off-axis NBI.

Details

ISSN :
13616587 and 07413335
Volume :
38
Database :
OpenAIRE
Journal :
Plasma Physics and Controlled Fusion
Accession number :
edsair.doi...........fe4e1af8d38353892fd5558fd76858d5
Full Text :
https://doi.org/10.1088/0741-3335/38/8/016