Double Layers In Magnetized Plasma Research Articles

Coupled drift and dust ion acoustic wave driven double layers in magnetized plasma with (r, q)-distributed electrons

The properties of coupled drift and dust ion acoustic wave (DIAW) driven nonlinear structures like solitary waves and double layers (DLs) are investigated in a magnetized inhomogeneous plasma carrying temperature and density inhomogeneities along with stationary dust. The electrons are assumed to follow double spectral index -distribution in which r shows the flat top nature while q is responsible for the shape of the distribution. A nonlinear differential equation is derived and its solution in the form of solitons and DLs is obtained by employing relevant boundary conditions. It is noted that coupled linear dust ion acoustic-drift wave and corresponding nonlinear structures are modified significantly under the variations in r and q. Only rarefactive solitons are obtained under the impact of various quantities especially r, q and normalized drift speed . However, both compressive and rarefactive double layers (DLs) are sustained/formed in such a plasma. It is noted in such an inhomogeneous, magnetized with non-Maxwellian character plasma that the amplitude of nonlinear structures is strongly dependent on the choice of parameters like r, q and . The study is important relevant to space plasmas.

Self-organization of multiple anodic double layers in magnetized plasma

We report on the self-organization of multiple double layers (MDLs) and self-organized criticality (SOC) behavior through subsequent layer reduction process around the anode during DC glow discharge in a linear cylindrical vacuum vessel. The present study provides an insight into the characteristic features of self-organized MDLs around the anode itself and the effect of an external magnetic field during its evolution. The MDL formations around the anode initiate through an abrupt jump in the floating potential, ion saturation, and discharge current signals, which suggests an associated sheath—plasma instability of the system. The frequency spectrum of the floating potential exhibits mixed mode oscillations, which later disappears on applying an external magnetic field. The comparative results reveal the complex nature of a simple glow discharge through repeated coupling and decoupling of MDL dynamics during layer reduction process in the presence of an external magnetic field in cusp configuration, while the discharge turns largely oscillatory in the presence of an external magnetic field in mirror configuration. Existence of the SOC behavior in the system is further investigated through nonlinear dynamical analysis of the floating potential fluctuations. The present study on self-organization phenomena in a glow discharge plasma is important for applications regarding utilization or mitigation of self-organization. Self-organized patterns are often formed during plasma interaction with the liquid surface, which play a vital role in diverse applications of plasmas in nanomaterial synthesis and medicine.

Ion-acoustic double layers in magnetized plasma consisting of warm adiabatic ions and non-thermal electrons having vortex-like velocity distribution: existence and stability

AbstractA combined Schamel's modified Korteweg–de Vries–Zakharov– Kuznetsov (S–KdV–ZK) equation efficiently describes the nonlinear behaviour of ion-acoustic waves in a plasma consisting of warm adiabatic ions and non-thermal electrons (due to the presence of fast energetic electrons) having vortex-like velocity distribution function (due to the presence of trapped electrons), immersed in a uniform (space-independent) and static (time-independent) magnetic field, when the vortex-like velocity distribution function of electrons approaches the non-thermal velocity distribution function of electrons as prescribed by Cairns et al. (1995 Electrostatic solitary structures in non-thermal plasmas.Geophys. Res. Lett.22, 2709–2712), i.e. when the contribution of trapped electrons tends to zero. This combined S–KdV–ZK equation admits a double-layer solution propagating obliquely to the external uniform and static magnetic field. The condition for the existence of this double-layer solution has been derived. The three-dimensional stabilities of the double-layer solutions propagating obliquely to the external uniform and static magnetic field have been investigated by the multiple-scale perturbation expansion method of Allen and Rowlands (1993 Determination of growth rate for linearized Zakharov–Kuznetsov equation.J. Plasma Phys.50, 413–424; 1995 Stability obliquely propagating plane solitons of the Zakharov–Kuznetsov equation.J. Plasma Phys.53, 63–73). It is found that the double-layer solutions of the combined S–KdV–ZK equation are stable at the lowest order, i.e. up to the orderk, wherekis the wave number of perturbation.

Kinematics of isobaric double layers in magnetized plasma

Kinematics of isobaric double layers in magnetized plasma