Drift wave instability in a magnetized plasma composed of positive ions and negative ions is considered using linear kinetic theory in the local approximation. We consider the case where the mass (temperature) of the negative ions is much larger (smaller) than that of the positive ions, and where the gyroradii of the two ion species are comparable. Weak collisional effects are taken into account. Application to possible laboratory parameters is discussed.

This paper presents the effect of self-focusing on a circularly polarized beam propagating along the static magnetic field when the extraordinary and ordinary modes are present simultaneously for relativistic intensities. The nonlinearity in the dielectric function arises on account of the relativistic variation of mass, which leads to the mutual coupling of the two modes that support the self-focusing of each other. The propagation and focusing of the first mode affects the propagation and focusing of the second mode. The fact that the two modes are laser-intensity dependent leads to cross-focusing. Dynamics of one laser beam affects the dynamics of the second laser beam. When both the beams or modes are strong, the nonlinearities introduced by the relativistic effect in the presence of the magnetic field are additive in nature, such that one beam can undergo oscillatory self-focusing and other beam simultaneously defocusing and vice versa. The dynamical equation governing the cross-focusing has been set up and a numerical solution has been presented for typical relativistic laser–plasma parameters from a slightly underdense to overdense plasma.

Anisotropic heating of ions by Alfvén waves with frequency in the ion–cyclotron frequency range and propagation parallel to the magnetic field lines is investigated. First, particle–Alfvén wave interactions are quasilinearly examined from the kinetic theory in a hot multi-ion-magnetized plasma. As a result, the parallel and perpendicular heating rates of ions are derived analytically. Then, in terms of this anisotropic heating model and the dispersion relation of magnetic field-aligned left-hand polarized electromagnetic ion–cyclotron–Alfvén (EMICA) waves, the resonant heating of H, 2H, 3H, 3He, and 4He ions in a typical preheated laboratory plasma is numerically studied. It is shown that the EMICA waves can efficiently heat ions through cyclotron resonances primarily in the perpendicular direction. The perpendicular temperatures of H, 2H, 3H, 3He, and 4He increase much faster than the parallel ones. In comparison with the result from the previously developed isotropic heating model, the parallel heating by the EMICA waves is about much weaker, while the perpendicular heating is more efficient. Parameters such as density, temperature, magnetic field, wave-energy density, and ion species can affect the efficiency of the Alfvén wave heating in a similar way as shown in the isotropic heating model. The anisotropic model can be applied to explain the measurements of why O+5 and Mg+9 are heated extreme perpendicularly in solar coronal holes.

The existence of plasmons with orbital angular momentum due to the Laguerre–Gaussian-type density and potential perturbations is studied in an unmagnetized quantum plasma. Starting from appropriate hydrodynamic equations for the electrostatic electron dynamics, a dispersion equation is derived in paraxial approximation. The Laguerre–Gaussian beam solutions are obtained and the properties of electric field components, energy flux, and corresponding angular momentum density of plasmons are investigated. The electric field lines are found to form helical structures with a dominant axial component. The results are analyzed numerically and the influence of radial and angular mode numbers on potential and electric field components is illustrated.