Observation of Radial Oscillations of Plasma Density and Magnetic Field in a Theta Pinch

This paper deals with the modeling of the ionospheric plasma. Starting from the two-fluid Euler–Maxwell equations, we present two hierarchies of models. The MHD hierarchy deals with large plasma density situations while the dynamo hierarchy is adapted to lower density situations. Most of the models encompassed by the dynamo hierarchy are classical ones, but we shall give a unified presentation of them which brings a new insight into their interrelations. By contrast, the MHD hierarchy involves a new (at least to the authors) model, the massless-MHD model. This is a diffusion system for the density and magnetic field which could be of great practical interest. Both hierarchies terminate with the "classical" Striation model, which we shall investigate in detail.

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An experimental investigation of current production by means of rotating magnetic fields

Journal of Plasma Physics ◽

10.1017/s0022377800010850 ◽

1981 ◽

Vol 26 (3) ◽

pp. 465-480 ◽

Cited By ~ 34

Author(s):

W. N. Hugrass ◽

I. R. Jones ◽

M. G. R. Phillips

Keyword(s):

Magnetic Field ◽

Experimental Investigation ◽

Threshold Value ◽

Rotating Magnetic Field ◽

Electron Current ◽

Rotating Magnetic Fields ◽

Theta Pinch ◽

Current Production ◽

Made In ◽

Rotating Field

An investigation of current production by means of a rotating magnetic field is made in an experiment in which the technique is used to generate a theta-pinch- like distribution of field and plasma. Detailed measurements are made of both the generated unidirectional azimuthal electron current and the penetration of the rotating field into the plasma. The experimental results support the theoretical prediction that a threshold value of the amplitude of the applied rotating field exists for setting the electrons into rotation.

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Plasma Density Fluctuations in a Magnetic Field

Physical Review ◽

10.1103/physrev.122.1663 ◽

1961 ◽

Vol 122 (6) ◽

pp. 1663-1674 ◽

Cited By ~ 105

Author(s):

E. E. Salpeter

Keyword(s):

Magnetic Field ◽

Plasma Density ◽

Density Fluctuations

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Saturn's Plasma Density Depletions Along Magnetic Field Lines Connected to the Main Rings

Geophysical Research Letters ◽

10.1029/2018gl078137 ◽

2018 ◽

Vol 45 (16) ◽

pp. 8104-8110 ◽

Cited By ~ 2

Author(s):

W. M. Farrell ◽

L. Z. Hadid ◽

M. W. Morooka ◽

W. S. Kurth ◽

J.‐E. Wahlund ◽

...

Keyword(s):

Magnetic Field ◽

Plasma Density ◽

Field Lines

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Europa's Alfvén wing: shrinkage and displacement influenced by an induced magnetic field

Annales Geophysicae ◽

10.5194/angeo-25-905-2007 ◽

2007 ◽

Vol 25 (4) ◽

pp. 905-914 ◽

Cited By ~ 14

Author(s):

M. Volwerk ◽

K. Khurana ◽

M. Kivelson

Keyword(s):

Magnetic Field ◽

Plasma Density ◽

Geometric Modeling ◽

Numerical Models ◽

Background Field ◽

Entry And Exit ◽

Induced Magnetic Field ◽

Background Magnetic Field ◽

Magnetometer Data ◽

Induced Field

Abstract. The Galileo magnetometer data are used to investigate the structure of the Alfvén wing during three flybys of Europa. The presence of an induced magnetic field is shown to shrink the cross section of the Alfvén wing and offset it along the direction radial to Jupiter. Both the shrinkage and the offset depend on the strength of the induced field. The entry and exit points of the spacecraft into and out of the Alfvén wings are modeled to determine the angle between the wings and the background magnetic field. Tracing of the Alfvén characteristics in a model magnetic field consisting of Jupiter's background field and an induced field in Europa produces an offset and shrinking of the Alfvén wing consistent with the geometric modeling. Thus we believe that the Alfvén wing properties have been determined correctly. The Alfvén wing angle is directly proportional to the local Alfvén velocity, and is thus a probe for the local plasma density. We show that the inferred plasma density can be understood in terms of the electron density measured by the plasma wave experiment. When Europa is located in the Jovian plasma sheet the derived mass-per-charge exceeds the previous estimates, which is a result of increased pickup of sputtered ions near the moon. The estimated rate of O2+ pickup agrees well with the results from numerical models.

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