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Author(s):
K.Sato,and F.Miyawaki
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Title:
Effects of a Nonuniform Open Magnetic Field on the Plasma Presheath
Date of publication:
Jan. 1991
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Key words:
presheath, open field plasma, expanding magnetic field, sheath, Bohm criterion
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Abstract:
Effects of a nonuniform magnetic field on the plasma presheath is numerically investigated using the plasma equation for a collisionless plasma with a finite-temperature particle source. The present calculation confirms that previously published analytical solutions [ Phys. Fluids B 1, 725 (1989) ] are available over a wide range of mirror ratio. Potential drop in the presheath, which considerably depends on both the magnetic strength profile and the spatial distribution of the particle source, is remarkably increased by applying an expanding magnetic field when plasma particles are generated in the inner part of the plasma. An effect of a nonuniform magnetic field on sheath formation is also discussed by using the calculated ion distribution function. If the plasma equation has no singularity at the sheath edge, its solution satisfies the generalized Bohm criterion with the inequality sign in the expanding magnetic field.
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