The modified Fokker–Planck collision operator for partially degenerate electrons was derived in an earlier paper [J. Plasma Phys.58, 577 (1997)]. This is now employed to study linear electron transport for a partially degenerate, magnetized plasma. Because polynomial expansions can yield incorrect transport coefficients owing to lack of resolution of the small fraction of low-energy unmagnetized electrons, a numerical discrete-ordinate scheme is employed. The inclusion of electron–electron collisions advances the model beyond that of Lee and More, and in the classical limit agrees with the results of Epperlein and Haines.

For a cold plasma that is inhomogeneous (in the direction across an external homogeneous magnetic field), the nonlinear equation describing the spatial structure and temporal behaviour of a non-stationary disturbance in a resonance layer is obtained. The matching conditions for a disturbance through the resonance layer are obtained, and in the linear limit give a well-known linear matching. It is shown that the spatial and temporal behaviour of the resonance disturbance and the evolution of the resonant absorption in terms of nonlinear theory are determined by the ratio of the nonlinear to linear non-stationary spatial scales. The spatial–temporal profile of the disturbance in the resonance layer and the resonant absorption for different values of this ratio are calculated. A nonlinear decrease in the resonant absorption and a stratification of the resonance disturbance are revealed.

The equations for the ideal, internal m = n = 1 kink mode in a toroidal plasma are derived from a direct, large-aspect-ratio perturbation expansion of the compressible magnetohydrodynamic (MHD) equations. The derivation complements earlier investigations of the internal kink mode based either on the energy principle or on direct expansions of the incompressible MHD equations. It is shown that five poloidal harmonics (m = −1, 0, 1, 2 and 3) have to be retained in a direct expansion of the compressible MHD equations, as compared with the three poloidal harmonics m = 0, 1 and 2 needed in the case of an incompressible plasma, or when working from the energy principle. Furthermore, the sound velocity is found to replace the Alfvén velocity in the generalized Pfirsch–Schlüter factor (the kinetic energy enhancement factor in a toroidal plasma) previously derived for an incompressible plasma. Taking this factor fully into account in the calculation of the growth rate of the m = n = 1 mode, it is shown that, while the Bussac result γB is recovered near marginal stability, growth rates of the order of 30% larger than γB are obtained when γB becomes of the order of the sound frequency.

Emission of energetic ions from solid targets irradiated by intense ultrashort laser pulses is studied in the framework of a one-dimensional self-consistent hydrodynamical model. The computed ion spectra reproduce well the basic parameters of published experimental results. Optimum conditions are found for the generation of MeV ions by picosecond laser pulses.

The time evolution of an incompressible non-ideal magnetohydrodynamic (MHD), current-carrying plasma with mass flow is investigated. An approach for the reduction of the nonlinear vector MHD equations to a set of scalar partial differential equations is supposed. Analytical time-dependent solutions of this system are presented. They describe kinetic plasma equilibria both with well-defined nested-in magnetic and velocity surfaces and in the form of vortices. The obtained solutions may be called ‘diffusion-like’, since their temporal structure is very similar to the solutions of the diffusion problem. It is shown that the magnetic field and the velocity have different dumping rates. In the asymptotic limit t→∞, the plasma slowly relaxes towards the hydrostatic equilibrium of gravitating systems.

Application of lower-hybrid (LH) power in short, intense pulses in the 5–10 GW range should overcome the limiting effects of Landau damping, and thereby permit the penetration of LH power into the interior of large-scale plasmas. We show that, under such very intense LH pulses, wave coupling may deteriorate because of nonlinear density changes due to the ponderomotive force effects in front of the grill. Ponderomotive forces are also likely to induce strong plasma bias and consequent poloidal and toroidal plasma rotation. Although backward electric currents, created in the plasma by intense LH pulses, dissipate a large portion of the radio frequency power absorbed, the current drive efficiency is acceptable. We use a numerical simulation of wave–particle interactions to analyse the applicability of standard quasilinear theory to the case of large energy flux densities. The initial results indicate the existence of important restrictions on the use of the quasilinear approximation. The results of the present paper also indicate that some of the effects considerably alter some ideas of Cohen et al.

The temporal evolution of weakly nonlinear, plane, linearly polarized Alfvén pulses in a cold homogeneous plasma is investigated. A static initial pulse-like disturbance in transverse velocity produces two Alfvén pulses that travel in opposite directions along the magnetic field. The ponderomotive force of the two pulses produces a static shock in longitudinal velocity at the starting position. The travelling pulses form a shock front that is governed by the scalar Cohen–Kulsrud equation. We find good agreement between the analytical solutions we derive and the results from a fully nonlinear numerical MHD code.

The properties of a relativistic plasma dispersion function (RPDF) for an intrinsically extremely relativist, strongly magnetized, one-dimensional, electron–positron plasma are discussed in detail. For a plasma with a mean Lorentz factor 〈γ〉 [Gt ] 1 in its rest frame, the RPDF has a large peak >〈γ〉 at a phase speed a fraction of order 1/〈γ〉 below the speed of light, and the asymptotic value (infinite phase speed) is 〈γ−3〉 ∼ 1/〈γ〉. These features are not particularly sensitive to the choice of distribution function. The RPDF is used to discuss the properties of waves in such plasmas. Particular points discussed are the implications of the RPDF for the maximum frequency for parallel Langmuir waves, and for the reconnection between the Langmuir mode and the Alfvén mode.

A class of relativistic dispersion functions for unmagnetized thermal plasmas is defined by generalizing functions first defined by Trubnikov in 1958. Recursion relations are derived that allow one to generate explicit expressions for the class of functions in terms of the relativistic plasma dispersion function T(z, ρ) introduced by Godfrey et al. in 1975. These functions are relevant to the description of the response of a weakly mangetized, highly relativistic, thermal plasma.