A strongly coupled dusty plasma system consisting of non-thermal electrons, Maxwellian ions, and negatively charged dust in presence of polarization force has been considered. The nonlinear propagation of dust-acoustic shock waves in such a dusty plasma system has been theoretically investigated by employing the reductive perturbation method. The effects of the polarization force and non-thermal electrons, on the properties of these dust-acoustic shock waves are briefly discussed. It is shown that the strong correlation among the charged dust grains is a source of dissipation, and is responsible for the formation of the dust-acoustic shock waves. It has been found that the effects of polarization force and non-thermal electrons significantly modify the basic features of such shock waves. It has been proposed to design a new laboratory experiment, which will be able to identify the basic features of the dust-acoustic shock waves predicted in this present investigation.

A description of the evolution of the initial disturbance in the fast magnetosonic (FMS) waveguide in transversely inhomogeneous plasma, given a weak coupling between FMS and Alfven modes, is made. It is shown that the Fourier transform of the FMS waveguide disturbance with respect to the coordinates along which plasma is homogeneous can be presented as a superposition of collective modes of the leading approximation with respect to the weak FMS–Alfven wave coupling from the initial instant of time. Frequencies of such collective modes and dependence of their structures on the coordinate along the inhomogeneity are found without taking the FMS–Alfven resonance into consideration, and the mode decrements are calculated using the perturbation technique. On the basis of such a representation of the FMS waveguide disturbance, the evolution of Alfven waves generating with waveguide mode packets produced by the initial disturbance of an arbitrary longitudinal structure is described. It is shown that the longitudinal structure of the Alfven disturbance generated by the collective mode packet is determined by the ratio between longitudinal scales of the initial disturbance and scales specified by resonance conditions (the resonance longitudinal wave number and the width of the range of the resonance longitudinal wave numbers). The structures of Alfven disturbances for the cases of such different ratios are described.

We study the spin and ion effects in quantum plasma, where the two-fluid model of electrons is being used which treats the spin-up and -down populations relative to the magnetic field as different species. We find the susceptibility of electrons and ions where the ions are classical, but strongly coupled. The general dispersion relation is derived for wave propagation in homogeneous magnetized plasmas for arbitrary direction of propagation. We discuss the applicability of our results.

The production of aluminium and zinc plasmas for the deposition of coatings upon steel strip is monitored by optical emission spectroscopy measurements. The plasma is created from an inductive source. The atom and the ion densities as well as the electron temperature are obtained such that the plasma can be characterized. It will be shown that the obtained plasmas are typically highly ionized and deviate from thermal equilibrium.

Properties of the coupled dust ion-acoustic drift wave instability in a radially bounded dusty magnetoplasma with an equilibrium sheared parallel ion (SPI) flow are investigated. By using the two-fluid model for the electrons and ions, a wave equation for the low-frequency coupled dust ion-acoustic drift waves in a bounded plasma with stationary charged dust grains is derived. The wave equation admits a linear dispersion relation, which exhibits that the radial boundary affects the growth rate of the coupled ion-acoustic drift wave instability which is excited by the SPI flow. The results should be relevant to dusty magnetoplasma experiments with an SPI flow.

The properties of non-planar (cylindrical and spherical) ion acoustic solitary waves (IASWs) in an unmagnetized collisionless electron-positron-ion (e-p-i) plasma, whose constituents are inertial ions and superthermal/non-Maxwellian electrons and positrons (represented by the kappa (κ) distribution), are investigated by deriving the modified Gardner (MG) equation. The well-known reductive perturbation method is employed to derive the MG equation. The basic features of non-planar IA Gardner solitons (GSs) are discussed. It is seen that the properties of non-planar IAGSs (positive and negative) differ significantly as the value of spectral index kappa changes.

Inertial and diffusive effects on the propagation of hydromagnetic waves in plasmas of finite conductivity are explored by assuming a finite relaxation time for the current density. The domain of validity of the hydromagnetic approximation is determined by defining a lower limit for the perturbative wavelength. Three independent dispersion relations are obtained. At short wavelengths, it is found that the longitudinal component of the perturbative magnetic field damps out at a finite rate, which is determined fully by the relaxation time of the current density. In the same limit, it is shown that Alfvén waves can propagate through conductive plasmas with a null group speed. It is also shown that strong inertial and diffusive effects on magnetosonic waves can be discussed by defining suitably a perturbative parameter with the dimension of speed. It is argued that relevant corrections to space and time scales describing the reconnection of magnetic field lines are expected by applying the results presented here at sufficiently high frequencies.

The application of pulsed power to transient radiofrequency/microwave radiation for warhead/projectile payloads is currently a significant area of research. In this paper, the far-field radiative property of a plasma antenna is analyzed. Then, a plasma jet is generated by burning chemicals, in which the electron concentration and collision frequency are diagnosed, and the electric conductance is calculated. Finally, the feasibility to apply the plasma jet as antenna is investigated by analyzing the radiative pattern. The dependency of pattern on plasma electron density, collision frequency, and plasma wake radius is calculated and analyzed.

The dispersion relation for lattice waves in a linear chain of charged particles in a complex plasma has been derived on the basis of a screened inter-grain repulsive potential and an attractive shadow potential 1/r. It is seen that the inclusion of the attractive potential makes a significant difference in the results; the present results are in good agreement with the experiment. The dispersion relations, corresponding to square and hexagonal planar lattices, with vibrations confined to the plane have also been derived.

A theoretical investigation on the nonlinear propagation of ion-acoustic waves in a degenerate dense plasma has been made by employing the reductive perturbation method. The Burger's equation has been derived, and numerically analyzed. The basic features of electrostatic shock structures have been examined. It has been shown that the plasma system under consideration supports the propagation of electrostatic shock structures. The implications of our results (obtained from this investigation) in compact astrophysical objects have been briefly discussed.

The CHIPIC code, a fully electromagnetic particle-in-cell (PIC) code for modeling and simulations of high-power microwave (HPM) devices, is introduced in this paper. It consists of a two-dimensional (2D) code and a three-dimensional (3D) code. The 2D code can model and simulate HPM devices with symmetric structure on 2D Cartesian, cylindrical and polar grids, while the 3D code can model and simulate HPM devices on 3D Cartesian and cylindrical grids. The fields are calculated using the finite-difference time-domain scheme, and the particles are described by the PIC scheme. Various types of boundary conditions have also been implemented for different kinds of applications. In addition, the 3D code is specifically designed for high-performance modeling and computing. It uses the message passing interface and the open specifications for multiprocessing (OpenMP) for parallelization. Its parallel design ensures that it is capable of efficiently executing on a variety of architectures. In order to allow efficient use of parallel architectures, it provides automated partitioning and dynamic load balancing. Even though this code is still in development, it has successfully simulated various real-world HPM experimental devices. Simulation results on some typical HPM devices by using the CHIPIC code are given, which agree well with those obtained from some well-known PIC codes. Direction for future work is also presented.

The streamer propagation in point-plane, non-uniform gaps under high applied electric fields, prior to the impact of primary streamer on cathode, is analyzed. The configuration used is an anode hyperboloid with 50-μm radius of curvature, and a flat plate as the cathode. The applied voltage is 130-kV direct current, and an initial electron is assumed to exist close to the anode in ambient air. The geometry used is a two-dimensional axisymmetry with a gap of 5 cm between the anode and the cathode. It is shown that the streamer is formed on the anode tip as expected, and midway toward the cathode, it separates into two streamers, the primary streamer that continues its propagation toward the cathode, and the branched streamer expanding radially toward the outer boundaries. The qualitative behavior of the discharge is analyzed in terms of streamer speeds, radial and axial electric fields, charged particle densities, and conductive currents. A branched streamer plasma structure was observed along the path of the primary plasma structure expanding radially outwards.

Nonlinear dust-acoustic (DA) shock waves in coupled dusty plasmas with negative dust grains and kappa-distributed electrons are discussed. Using a generalized hydrodynamic model, the dispersion relation and the Korteweg–de Vries-Burger (KdVB) equation for low-frequency DA modes in a strongly coupled dusty plasma are derived. The dependence of shock waves on various plasma parameters is then explored. A solitonic profile may be converted into a shock structure when correlation among dust particles becomes stronger. The amplitude as well as the steepness of shock waves increases with increasing the value of the spectral index k.

The instability of dust acoustic waves driven by electrons and ions with different drift velocities in dusty non-extensive plasma is investigated based on the kinetic theory. The non-extensivity parameters of non-extensive distribution for three plasma components are different from each other. The instability growth rate is shown to be dependent on the non-extensivity parameters as well as on the ion--electron number density ratio. In the extensive limit (q=1), the result in Maxwellian distribution plasma is recovered. The instability growth rate is found to decrease as the population of suprathermal electrons and dust grains increases, but it enhances when the number of suprathermal ions increases and electron density decreases.

The non-thermal shielding effects on the Ramsauer phenomena for the electron–atom-induced dipole scattering are investigated in Lorentzian plasmas. The phase theory and the modified Buckingham-type potential are employed to obtain phase shift and collision cross section as functions of spectral index, scattering length, polarizability, collision energy, and the Debye radius. It is found that the non-thermal effect enhances the collision cross section below the Ramsauer energy and suppresses the collision cross section above the Ramsauer energy. In addition, it is found that the non-thermal effect enhances the Ramsauer energy in Lorentzian plasmas.