Azimuthal plasma pressure gradient in quiet time plasma sheet

Abstract The effect of equilibrium poloidal flow and pressure gradient on the m/n = 2/1 (m is the poloidal mode number and n is the toroidal mode number) tearing mode instability for tokamak plasmas is investigated. Based on the condition of ≠0 ( is plasma pressure), the radial part of motion equation is derived and approximately solved for large poloidal mode numbers (m). By solving partial differential equation (Whittaker equation) containing second order singularity, the tearing mode stability index Δ′ is obtained. It is shown that, the effect of equilibrium poloidal flow and pressure gradient has the adverse effect on the tearing mode instability when the pressure gradient is nonzero. The poloidal equilibrium flow with pressure perturbation partially reduces the stability of the classical tearing mode. But the larger pressure gradient in a certain poloidal flow velocity range can abate the adverse influence of equilibrium poloidal flow and pressure gradient. The numerical results do also indicate that the derivative of pressure gradient has a significant influence on the determination of instability region of the poloidal flow with pressure perturbation.

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Observational determination of the adiabatic index in the quiet time plasma sheet

Geophysical Research Letters ◽

10.1029/gl016i006p00563 ◽

1989 ◽

Vol 16 (6) ◽

pp. 563-566 ◽

Cited By ~ 71

Author(s):

C. Y. Huang ◽

C. K. Goertz ◽

L. A. Frank ◽

G. Rostoker

Keyword(s):

Plasma Sheet ◽

Adiabatic Index ◽

Quiet Time

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Examining the Magnetic Signal Due To Gravity and Plasma Pressure Gradient Current With the TIE-GCM

Journal of Geophysical Research Space Physics ◽

10.1002/2017ja024841 ◽

2017 ◽

Vol 122 (12) ◽

pp. 12,486-12,504 ◽

Cited By ~ 5

Author(s):

A. Maute ◽

A. D. Richmond

Keyword(s):

Pressure Gradient ◽

Plasma Pressure ◽

Magnetic Signal

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Effects of spatial diffusion in the inner plasma sheet and the structure of the diffusion tensor

Annales Geophysicae ◽

10.1007/s00585-995-0111-2 ◽

1995 ◽

Vol 13 (2) ◽

pp. 111-117 ◽

Cited By ~ 1

Author(s):

V. E. Zakharov ◽

M. I. Pudovkin

Keyword(s):

Flux Tube ◽

Plasma Sheet ◽

Diffusion Tensor ◽

Plasma Pressure ◽

Spatial Diffusion ◽

Angle Distribution ◽

Inner Magnetosphere ◽

Electron Population ◽

Magnetospheric Convection ◽

Isotropic Pitch

Abstract. A standard pair of equations is used to describe the behaviour of a single monoenergetic particle (proton or electron) population on a geomagnetic flux tube drifting in the magnetosphere. When particle losses from the drifting flux tube into the ionosphere are neglected, this behaviour is adiabatic in a thermodynamic sense. For a population of particles with an isotropic pitch-angle distribution, the generalization of that system of equations is obtained by adding radial and azimuthal spatial diffusion terms. The magnetic field is taken to be dipolar in the inner magnetosphere. The potential electric field is assumed to consist of magnetospheric convection and corotation components. Experimental data are used to estimate the radial equatorial profiles of the plasma sheet pressure. Assuming that the local time and L-shell variations are separable and supposing steady-state conditions, the expressions for the diffusion tensor components are evaluated. The influence of spatial diffusion on the radial and azimuthal profiles of the plasma pressure in the inner plasma sheet is also discussed.

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Guided waves in the plasma sheet and triggering of a substorm

Annales Geophysicae ◽

10.1007/s00585-994-1018-z ◽

1994 ◽

Vol 12 (10/11) ◽

pp. 1018-1021 ◽

Cited By ~ 3

Author(s):

V. V. Safargaleev ◽

V. B. Lyatsky

Keyword(s):

Plasma Sheet ◽

Guided Waves ◽

Solar Wind Plasma ◽

Plasma Pressure ◽

Magnetoacoustic Wave ◽

Sudden Impulse ◽

Field Lines ◽

Guided Propagation ◽

The Magnetic Field ◽

Half Thickness

Abstract. A guided propagation of magnetoacoustic wave in the plasma sheet located between two lobes of the magnetotail is investigated. The dispersion equation for the wave and equation connecting a disturbance of plasma pressure inside the plasma sheet and amplitude of the plasma sheet boundary oscillations are obtained. For some value of plasma pressure disturbance, the displacement of the plasma sheet boundaries becomes of order of the half-thickness of the plasma sheet. In the case of symmetrical oscillations of the boundaries ("sausage-like" mode), it creates the favourable conditions for reconnection of the magnetic field lines in the magnetotail and may lead to triggering of a substorm. The magnetoacoustic wave may be generated by sudden impulse of the solar wind plasma pressure.

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