Oblique propagation of arbitrary amplitude electron acoustic solitary waves in magnetized kappa-distributed plasmas

Abstract

Abstract. The linear and nonlinear properties of large amplitude electron-acoustic waves are investigated in a magnetized plasma comprising two distinct electron populations (hot and cold) and immobile ions. The hot electrons are assumed to be in a non-Maxwellian state, characterized by an excess of superthermal particles, here modelled by a kappa-type long-tailed distribution function. Waves are assumed to propagate obliquely to the ambient magnetic field. Two types of electrostatic modes are shown to exist in the linear regime, and their properties are briefly analyzed. A nonlinear pseudopotential type analysis reveals the existence of large amplitude electrostatic solitary waves and allows for an investigation of their propagation characteristics and existence domain, in terms of the soliton speed (Mach number). The effects of the key plasma configuration parameters, namely, the superthermality index and the cold electron density, on the soliton characteristics and existence domain, are studied. The role of obliqueness and magnetic field are discussed.

Electrostatic Shock Structures in Nonextensive Plasma with Two Distinct Temperature Electrons

“…The concept of two-temperature electrons (electrons with two distinct temperatures) is now well established from the theoretical [34][35][36][37][38] and experimental [39,40] points of view. Thus, at equilibrium the quasineutrality condition implies, n i0 = n e10 + n e20 + Z d n d0 , where n s0 is the unperturbed number densities of the species s (here s = i, e1, e2, d for ion, electrons with temperature T e1 , electrons with temperature T e2 , and immobile dust, respectively) and Z d is the number of electrons residing onto the dust grain surface.…”

Higher-order solitary structures of nonextensive electrons having two distinct temperatures in a dusty plasma

“…The concept of two-temperature electrons (electrons with two distinct temperatures) is now well established from the theoretical [48][49][50] and experimental [51,52] points of view. Thus, at equilibrium, we have n i0 = n e10 + n e20 + Z d n d0 , where Z d is the number of electrons residing on the surface of a dust grain, n i0 , n e10 , n e20 , and n d0 are, respectively, the number densities of equilibrium ions, electrons with temperature T e1 , electrons with temperature T e2 , and dust particles.…”

Oblique propagation of solitary electrostatic waves in magnetized plasmas with cold ions and nonthermal electrons

“…Oblique propagation of electrostatic waves and solitary structures in magnetized plasmas has, over the years, been investigated by several authors. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] The discussion has been carried out from different viewpoints: linear waves or weakly nonlinear solitons described by the reductive perturbation theory, or, less commonly, larger amplitude solitary structures treated through a Sagdeev pseudopotential approach. 15 It is the latter method that interests us here even though some authors also mention linear dispersion properties and/or cite weakly nonlinear results (but derived as a limiting case from the fully nonlinear approach).…”

“…Most of the papers studying oblique propagation of electrostatic modes in magnetized plasmas take the static field along one axis, thus leaving x and z as independent variables, in addition to time t. Later, a comoving coordinate is introduced to carry the analysis through, reducing the description to one effective coordinate. [1][2][3]5,7,[9][10][11][12][13][14] Another choice, one that we tend to prefer because it is simpler to work with, is that one axis is chosen along the direction of propagation and immediately in a comoving reference frame. 4,6,8 Working in the frame where the structure is stationary gives rise to straightforward integrations with respect to x, as t is eliminated from the very beginning.…”

“…As to the plasma models discussed, the fluid constituent is usually positive ions, which are treated as strictly cold 1,2,[4][5][6][7][8][9]12,13 or warm, 3,10,14 with various polytropic pressure-density relations, or else one cold electron component and an immobile background. 11 The hot electrons are inertialess and have different distributions: in the early days, Boltzmann, [1][2][3][4][5]7,8 more recently kappa, 9,11,13 Tsallis, 12 or Cairns. 14 We quote some generic references for these distributions.…”