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Title: Evolution of neutral-beam-driven current in tokamak plasmas

Abstract

Neutral-beam heating and current induction have been analyzed with a one-dimensional model that includes a Fokker-Planck analysis of the circulating ion current, the time and space dependence of the electron ''return'' current, and the steady electron shielding current including electron trapping effects. With 1.2 MW of 40 keV H/sup 0/ injected tangentially into a 25-cm radius PLT plasma with = 2.0 x 10/sup 13/ cm/sup -3/, the maximum beam-driven current is about 100 kA and results in a 0.24-V reduction in loop voltage. Reversed loop voltages should be observable in low density plasmas in ISX-B and TFTR, which would provide an unambiguous detection of the beam-driven current. When the radial profiles of beam-driven current are less peaked than the ohmic-current profile, the profiles of the ''safety factor'' q should be more stable to n = 1, m = 1 and n = 1, m = 2 kink modes, if the total plasma current is kept constant.

Authors:
; ; ;
Publication Date:
Research Org.:
Princeton Univ., NJ (USA). Plasma Physics Lab.
OSTI Identifier:
6688013
Report Number(s):
PPPL-1438; CONF-780702-2
TRN: 78-017000
DOE Contract Number:  
EY-76-C-02-3073
Resource Type:
Conference
Resource Relation:
Conference: Symposium on heating in toroidal plasmas, Grenoble, France, 3 Jul 1978
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; NEUTRAL ATOM BEAM INJECTION; ELECTRIC CURRENTS; TOKAMAK DEVICES; ELECTRIC POTENTIAL; FOKKER-PLANCK EQUATION; ONE-DIMENSIONAL CALCULATIONS; SHIELDING; TRAPPING; BEAM INJECTION; CLOSED PLASMA DEVICES; CURRENTS; DIFFERENTIAL EQUATIONS; EQUATIONS; THERMONUCLEAR DEVICES; 700205* - Fusion Power Plant Technology- Fuel, Heating, & Injection Systems

Citation Formats

Singer, C E, Bromberg, L, Hovey, J, and Jassby, D L. Evolution of neutral-beam-driven current in tokamak plasmas. United States: N. p., 1978. Web.
Singer, C E, Bromberg, L, Hovey, J, & Jassby, D L. Evolution of neutral-beam-driven current in tokamak plasmas. United States.
Singer, C E, Bromberg, L, Hovey, J, and Jassby, D L. 1978. "Evolution of neutral-beam-driven current in tokamak plasmas". United States. https://www.osti.gov/servlets/purl/6688013.
@article{osti_6688013,
title = {Evolution of neutral-beam-driven current in tokamak plasmas},
author = {Singer, C E and Bromberg, L and Hovey, J and Jassby, D L},
abstractNote = {Neutral-beam heating and current induction have been analyzed with a one-dimensional model that includes a Fokker-Planck analysis of the circulating ion current, the time and space dependence of the electron ''return'' current, and the steady electron shielding current including electron trapping effects. With 1.2 MW of 40 keV H/sup 0/ injected tangentially into a 25-cm radius PLT plasma with = 2.0 x 10/sup 13/ cm/sup -3/, the maximum beam-driven current is about 100 kA and results in a 0.24-V reduction in loop voltage. Reversed loop voltages should be observable in low density plasmas in ISX-B and TFTR, which would provide an unambiguous detection of the beam-driven current. When the radial profiles of beam-driven current are less peaked than the ohmic-current profile, the profiles of the ''safety factor'' q should be more stable to n = 1, m = 1 and n = 1, m = 2 kink modes, if the total plasma current is kept constant.},
doi = {},
url = {https://www.osti.gov/biblio/6688013}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1978},
month = {4}
}

Conference:
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