Stochastic generation of currents by lower-hybrid waves
A scheme for current generation based on a stochastic driving mechanism is proposed. The current in this approach is generated by launching into the plasma two lower-hybrid waves having appropriate different frequencies, wave numbers, and amplitudes. The phase-space analysis of the electron motion in such a configuration reveals the existence of a relatively broad stochastic layer far away from the separatrix, allowing for diffusion in velocity space of high-velocity electrons. The diffusion coefficient of this process is evaluated and the solution of the Fokker-Planck equation for the electron velocity distribution function is used to calculate the current J and the power dissipated P/sub d/ in generating it. A favorable J-to-P/sub d/ ratio for steady-current drive is found.
- Research Organization:
- Physics Department, Nuclear Development Corporation of South Africa, Private Bag X256, Pretoria 0001, Republic of South Africa
- OSTI ID:
- 6998490
- Journal Information:
- Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 29:3; ISSN PLRAA
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
700108* -- Fusion Energy-- Plasma Research-- Wave Phenomena
ACCELERATION
BEAM EXTRACTION
CLOSED PLASMA DEVICES
CURRENT DENSITY
CURRENTS
DIFFERENTIAL EQUATIONS
DIFFUSION
DISTRIBUTION FUNCTIONS
EFFICIENCY
ELECTRIC CURRENTS
ELECTRONS
ELEMENTARY PARTICLES
EQUATIONS
FERMIONS
FOKKER-PLANCK EQUATION
FUNCTIONS
INJECTION
INTAKE
ION PLASMA WAVES
ION WAVES
LEPTONS
MATHEMATICAL SPACE
PARTIAL DIFFERENTIAL EQUATIONS
PHASE SPACE
PINCH DEVICES
PLASMA
PLASMA WAVES
RF SYSTEMS
SPACE
STOCHASTIC PROCESSES
THERMONUCLEAR DEVICES
TOROIDAL PINCH DEVICES