Low aspect ratio tokamak formation and sustainment by coaxial helicity injection current drive

Journal Article · Sat Apr 01 00:00:00 EST 1995 · Fusion Technology

OSTI ID:219788

Nelson, B A; Jarboe, T R; Orvis, D J; Martin, A K; Xie, J; Zhang, C; Zhou, L ^[1]

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1. Univ. of Washington, Seattle, WA (United States)

Coaxial helicity injection is used to form and sustain low aspect ratio tokamaks at currents of up to 250 kA in the Helicity Injected Tokamak experiment. Plasma currents can be sustained at an average of 225 kA for 2 ms, with on axis electron thermal energies up to 80 eV, or for longer times, 140 kA average for 7 ms, many resistive diffusion times. Spectroscopic measurements of the higher current discharges suggest burn-through of oxygen impurities. These plasmas have a rotating n = 1 distortion, appearing only on the outer, bad-curvature region. Equilibria reconstruction , fitting to experimental data, shows tokamak q profiles achieved with hollow plasma current profiles. 11 refs., 4 figs., 1 tab.

• OSTI ID: 219788
• Report Number(s): CONF-941182-; ISSN 0748-1896; TRN: 96:010867
• Journal Information: Fusion Technology, Vol. 27; Conference: 6. international Toki conference on plasma physics and controlled nuclear fusion: Research for advanced concepts in magnetic fusion, Toki-city (Japan), 29 Nov - 2 Dec 1994; Other Information: PBD: Apr 1995
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION
TOKAMAK DEVICES
BEAM INJECTION
PLASMA CONFINEMENT
ASPECT RATIO
HELICITY
OXYGEN
PLASMA IMPURITIES
CURRENT-DRIVE HEATING
ELECTRIC CURRENTS