The effect of finite ion Larmor radius on the Kelvin–Helmholtz instability is investigated in the cases of an incompressible and a compressible plasma. When a wave vector is perpendicular to a uniform magnetic field, the effect of finite Larmor radius (FLR) stabilizes perturbations with a wavenumber exceeding a critical value, while there exists another case that the FLR effect destabilizes still more than the usual MHD approximation. The difference between these cases is decided from the configuration of flow velocity and magnetic field. When a wave vector is parallel to a magnetic field, the FLR effect tends to stabilize perturbations with a larger wavenumber.

Baker proposed a method of injecting charged particles into a static magnetic field such that particles on these ‘trapping orbits’ never return to the vicinity of the injector and remain permanently trapped. Their infinite confinement time requires that their energy, Eo, be specified with infinite precision. When the energy differs from this by a small amount, E, the particle escapes after a finite confinement time, of the order of In (Eo/E) cyclotron periods.

This paper is concerned with the derivation of linear wave equations for nonuniform magnetized Vlasov plasmas. By the operator method it is shown that a close connection exists between the case of perpendicular propagation and the general one. Combining this with previous results, expressions for the perturbed density and velocity are derived for the case of propagation at any angle to the uniform static magnetic field in a two-temperature Maxwellian plasma. These results apply for arbitrary inhomogeneities of equilibrium density and temperatures in directions perpendicular to the static magnetic field.

We consider nonlinear surface waves on a cold plasma half-space. It is found that for a certain region of the wavenumber spectrum, supersonic envelope surface wave solitons exist.

We investigate the problem of spatial depletion of propagating lower-hybrid waves in an inhomogeneous plasma. In particular, we consider the nonlinear evolution of a lower-hybrid pump which is coupled to a daughter lower-hybrid decay wave excited by low-frequency density perturbations. Our results show that pump depletion occurs when three-dimensional effects are included. This phenomenon competes with the filamentation of the pump caused by self- interaction. Implications to lower-hybrid heating experiments are discussed.

A formal derivation of the quasi-linear equation of a plasma in a magnetic field is presented. The theory accounts for spatial inhomogeneity in one direction and for bounce motion of particles confined in a mirror magnetic field.

A procedure is outlined for obtaining a high degree of quiescence in a magneto- plasma.

The stability of the solar wind against the whistler mode is analyzed. It is shown that the solar wind can become unstable owing to this mode after a distance of 100 R from the sun. The minimum value of the relative velocity (Ur) between ∝-particles and protons for the excitation of this instability is the proton thermal velocity αi. The maximum growth rate at 200 R occurs for the values of the parameters kρi = 0·3,(T┤/T∥)i = 0·3 and Ur/αi = 0·5.

A general self-consistent framework is developed for the calculation of transport coefficients in a collisionless, weakly turbulent plasma. These coefficients characterize the response to a perturbation away from a quasi-steady turbulent state, which is assumed to exist as a result of the stabilization of the linear instabilities. It is shown that a purely hydrodynamical description does not exist for plasmas: the macroscopic picture must include non-conserved quantities, which lead to the plasmadynamical (or ‘two-fluid’) picture of the system. The number of independent transport coefficients, necessary for the macroscopic characterization of the plasma, is correspondingly increased as compared with a two- component mixture of two ordinary fluids. The typical turbulent contributions to the transport coefficients are clearly exhibited.

Magnetosonic solitons may be given smooth increasing profiles by assuming the presence within the wave of a current distribution Jy(x) of trapped ions perpendicular to Bz(x) and the wave velocity Vx. Suitable ions are found immediately upstream of perpendicular, collisionless shock waves and these are coincident with the often observed ‘foot’ in magnetic field profiles of moderately supercritical shocks. By modelling Jy(x) we apply the theory to previous experiments where Jy(x) is observed, and are able to reproduce reasonably, and thus explain, the profiles in the foot. Insight into a number of features of fast shocks is obtained.

Using the two-fluid approximation, we summarize properties of linear waves in an unbounded magnetized relativistic plasma by a parameter-space diagram of wave phase velocity: a relativistic plasma pond.

In this paper we consider relativistic interaction of an overdense plasma with very intense electromagnetic waves. Nonlinear coupling of dispersive waves in the presence of an ambient magnetic field is investigated. Lorentz transformation together with rotations of the co-ordinate system are employed to obtain analytic solutions. Two cases with variable gamma factors are treated in detail: in one case the magnitude of the electric field remains constant in the transformed frame; in the other no restriction is made to the electric field, but the total stream velocity vanishes in the transformed frame. Numerical illustrations of various modes for these two cases are depicted graphically.

The tracing of the geometrical optics rays in toroidal geometry and in the electron-cyclotron frequency range has been done numerically. The results presented are relevant to the extraordinary-mode propagation and conversion at the upper-hybrid resonance layer. High-density regime refraction effects, together with strong bending of the warm Bernstein rays along the toroidal direction and resonance-cone structure generation, are the main features of the numerical output.