The Physics of Fluids · 1974 · 369 citations · 8 references
Natural SciencesPhysicsAstrophysicsHeat TransferPlasma PhysicsHigh-temperature PlasmasMagnetized PlasmaMagnetohydrodynamicsPlasma HeatingPlasma WavesPlasma-surface InteractionsAlfven WavesAlfvén WavesCollisionless HeatingCollisionless Plasma DynamicsCompressibilityMagnetic Flux DensityPlasma ResonancesResonance
The resonance of shear Alfvén waves arises from nonuniform Alfvén speed. The study proposes heating a collisionless plasma via spatial resonance of shear Alfvén waves and discusses its application to toroidal plasmas. The authors analyze a one‑dimensional heating scheme that incorporates shear magnetic fields, plasma compressibility, and smooth nonuniformities (|k⊥l|≫1), yielding an energy absorption per unit surface area per cycle of b0²/(μ0k⊥). For sharp nonuniformities (|k⊥l|≪1), absorption is large when a surface eigenmode is excited, scaling as b0²/(μ0k⊥)(k⊥l)⁻¹, and otherwise scales as b0²/(μ0k⊥)(k⊥l).
Heating of a collisionless plasma by utilizing the spatial resonance of shear Alfvén waves is proposed and application to toroidal plasmas is discussed. The resonance exists due to the nonuniform Alfvén speed. This heating scheme is analyzed in one dimension including the effects of a shear magnetic field and plasma compressibility. For plasmas with smooth nonuniformities (| k⊥l | ≫ 1, k⊥ is the wavenumber pre perpendicular to the ambient magnetic field and the nonuniformity direction, and l is the scale length of the nonuniformity), the energy absorbed per unit surface area per driving cycle is [b02(μ0k⊥)−1]. Here, b0 is the flux density of the driving magnetic field evaluated at the resonant point. With sharp nonuniformities (| k⊥l | ≪ 1), absorption is large if the surface eigenmode is excited. The corresponding value is [b02(μ0k⊥)−1(k⊥l)−1]. Otherwise, it is [b02(μ0k⊥)−1(k⊥l)].
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Plasma Heating by Alfvén-Wave Phase Mixing
Akira Hasegawa, Liu Chen · Physical Review Letters · 1974 · 231 citations
Excitation of the Plasmapause at Ultralow Frequencies
L. J. Lanzerotti, H. Fukunishi, Akira Hasegawa et al. · Physical Review Letters · 1973 · 64 citations