Fast electron transport in lower-hybrid current drive

Journal Article · Tue Oct 01 04:00:00 EDT 1991 · Physics of Fluids B; (United States)

DOI:https://doi.org/10.1063/1.859914· OSTI ID:5216835

Kupfer, K; Bers, A ^[1]

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1. Plasma Fusion Center and Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts (USA)

The quasilinear Fokker--Planck formulation is generalized for lower-hybrid current drive to include the wave-induced radial transport of fast electrons. Toroidal ray tracing shows that the wave fields in the plasma develop a large poloidal component associated with the upshift in {ital k}{sub {parallel}} and the filling of the spectral gap.'' These fields lead to an enhanced radial {ital E}{times}{ital B} drift of resonant electrons. Two types of radial flows are obtained: an outward convective flow driven by the asymmetry in the poloidal wave spectrum, and a diffusive flow proportional to the width of the poloidal spectrum. Numerical results relevant to Alcator C (Phys. Rev. Lett. {bold 53}, 450 (1984)) and JT-60 (Nucl. Fusion {bold 29}, 1815 (1989)) are presented; they show that the radial convection velocity has a broad maximum of nearly 1 m/sec and is independent of the amplitude of fields. In both cases, the radial diffusion is found to be highly localized near the magnetic axis. For JT-60, the peak of the diffusion profile can be quite large, nearly 1 m{sup 2}/sec.

• DOE Contract Number: FG02-91ER54109
• OSTI ID: 5216835
• Journal Information: Physics of Fluids B; (United States), Journal Name: Physics of Fluids B; (United States) Vol. 3:10; ISSN PFBPE; ISSN 0899-8221
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700101 -- Fusion Energy-- Plasma Research-- Confinement
Heating
& Production
700103* -- Fusion Energy-- Plasma Research-- Kinetics
ANNULAR SPACE
CLOSED CONFIGURATIONS
CLOSED PLASMA DEVICES
CONFIGURATION
CONVECTION
CURRENT-DRIVE HEATING
DAMPING
DIFFERENTIAL EQUATIONS
DIFFUSION
ELECTRIC HEATING
ENERGY TRANSFER
EQUATIONS
FOKKER-PLANCK EQUATION
HEAT TRANSFER
HEATING
HIGH-FREQUENCY HEATING
JOULE HEATING
LOWER HYBRID HEATING
MAGNETIC FIELD CONFIGURATIONS
MASS TRANSFER
PARTIAL DIFFERENTIAL EQUATIONS
PLASMA
PLASMA HEATING
RESISTANCE HEATING
RESONANCE
SPACE
THERMONUCLEAR DEVICES
TOKAMAK DEVICES
TOROIDAL CONFIGURATION