scholarly journals THREE-DIMENSIONAL MULTISPECIES DISTRIBUTION FUNCTIONS IN A PLASMA BOUNDARY WITH AN OBLIQUE MAGNETIC FIELD

2018 ◽  
Author(s):  
Derek S Thompson
2016 ◽  
Vol 34 (12) ◽  
pp. 1175-1189 ◽  
Author(s):  
Chris Gurgiolo ◽  
Melvyn L. Goldstein

Abstract. Observations of the three-dimensional solar wind electron velocity distribution functions (VDF) using ϕ–θ plots often show a tongue of electrons that begins at the strahl and stretches toward a new population of electrons, termed the proto-halo, that exists near the projection of the magnetic field opposite that associated with the strahl. The energy range in which the tongue and proto-halo are observed forms a “diffusion zone”. The tongue first appears in energy generally near the lower-energy range of the strahl and in the absence of any clear core/halo signature. While the ϕ–θ plots give the appearance that the tongue and proto-halo are derived from the strahl, a close examination of their density suggests that their source is probably the upper-energy core/halo electrons which have been scattered by one or more processes into these populations.


2016 ◽  
Vol 795 ◽  
pp. 847-875 ◽  
Author(s):  
Habibur Rahman ◽  
Sergey A. Suslov

The stability of base gravitational convection in a layer of ferrofluid confined between two vertical wide and tall non-magnetic plates, heated from one side, cooled from the other and placed in a uniform oblique external magnetic field is studied. Two distinct mechanisms, thermo-gravitational and thermo-magnetic, are found to be responsible for the appearance of various stationary and wave-like instability modes. The characteristics of all instability modes are investigated as functions of the orientation angles of the applied magnetic field and its magnitude for various values of magnetic parameters when both the thermo-magnetic and gravitational buoyancy mechanisms are active. The original three-dimensional problem is cast in an equivalent two-dimensional form using generalised Squire’s transformations, which significantly reduces a computational cost. Subsequently, full three-dimensional instability patterns are recovered using the inverse Squire’s transformation, and the optimal field and pattern orientations are determined.


1998 ◽  
Vol 498 (1) ◽  
pp. 166-169 ◽  
Author(s):  
Ken‐Ichi Nishikawa ◽  
Shinji Koide ◽  
Jun‐ichi Sakai ◽  
Dimitris M. Christodoulou ◽  
Helene Sol ◽  
...  

2020 ◽  
Vol 27 (7) ◽  
pp. 073511 ◽  
Author(s):  
Derek S. Thompson ◽  
Rinat Khaziev ◽  
Miguel Fortney-Henriquez ◽  
Shane Keniley ◽  
Earl E. Scime ◽  
...  

2002 ◽  
Vol 9 (2) ◽  
pp. 101-109 ◽  
Author(s):  
L. Muschietti ◽  
I. Roth ◽  
C. W. Carlson ◽  
M. Berthomier

Abstract. A model is presented for a new type of fast solitary waves which is observed in downward current regions of the auroral zone. The three-dimensional, coherent structures are electrostatic, have a positive potential, and move along the magnetic field lines with speeds on the order of the electron drift. Their parallel potential profile is flattened and cannot fit to the Gaussian shape used in previous work. We develop a detailed BGK model which includes a flattened potential and an assumed cylindrical symmetry around a centric magnetic field line. The model envisions concentric shells of trapped electrons slowly drifting azimuthally while bouncing back and forth in the parallel direction. The electron dynamics is analysed in terms of three basic motions that occur on different time scales characterized by the cyclotron frequency We , the bounce frequency wb , and the azimuthal drift frequency wg. The ordering We >> wb >> wg is required. Self-consistent distribution functions are calculated in terms of approximate constants of motion. Constraints on the parameters characterizing the amplitude and shape of the stretched solitary wave are discussed.


2003 ◽  
Vol 21 (9) ◽  
pp. 1939-1946 ◽  
Author(s):  
X. H. Deng ◽  
H. Matsumoto ◽  
H. Kojima ◽  
R. R. Anderson ◽  
T. Mukai ◽  
...  

Abstract. In this paper we report new kinetic features of ions and electrons observed in the vicinity of the reconnection layer on 10 January 1997. This event has a three-dimensional magnetic field topological structure, which is much more complex than the previously suggested two-dimensional magnetic configuration. The ion distributions are non-gyrotropic and electrons show non-Maxwellian distribution functions. Acceleration of multiple ion beams, both parallel and perpendicular to the local magnetic field, have been observed. The perpendicular acceleration of the multiple ion beams can be explained by plasma mixing between the meandering ions accelerated around the ion diffusion region and the cold ions convected directly from the magnetosheath without passing through the X-line region. The parallel acceleration of the multiple ion beams can be understood by the fact that high-velocity ions ejected from the vicinity of the X-line mix with the plasma flowing directly across the boundary. We observed the kinetic effect of the separation of the electron and ion edges due to the time-of-flight effect. It is stressed that kinetic processes are the key to understanding these new observations that cannot be adequately explained by magnetohydrodynamic (MHD) models.Key words. Space plasma physics (magnetic reconnection; charged particle motion and acceleration) – Magnetospheric physics (magnetopause, cusp, and boundary layers)


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