A pulsed, multi-stage, high-voltage accelerator is proposed which should be capable of producing intense ion beams of many million amperes and many million volts. Super ion beams produced by this type of accelerator can exceed the limiting Aifvén current for light ions, typically 107 A, at which beam pinching occurs. The beam pinching of these super-beams permits them to be precisely focused onto a thermonuclear target. With such an accelerator it seems to be possible to reach a beam voltage of 108 V with a beam current of 107 A. The resulting beam power of 1015 W should be more than sufficient to ignite a DT thermonuclear microexplosion. By the formation of a stable ion beam superpinch within a thermonuclear target, such a large beam power in conjunction with the strong self-magnetic field of the beam may even lead to the ignition of the DD and perhaps HB11 thermonuclear reactions.

Considering the influence of relativistic effects on the plasma motion in a HF field, we show that even small relativistic terms qualitatively change the propagation character of nonlinear longitudinal and transverse waves. We also find new regions and branches for the modulational instability.

Any ion distribution f;i =(θ—ώit) is an exact solution of the Vlasov equation for a uniformly magnetized plasma. Here θ is the phase angle in velocity space and ώi is the Larmor frequency. Then fi rotates rigidly in velocity space with frequency ώ;i about an axis along a magnetic field line. If fi has anisotropy in the perpendicular velocity plane of the form fi(V, t) = fi(V) [1+A cos 2(θ— ώit)], then it represents a density modulation of frequency 2ώ;i which is confined to velocity space. This non-Maxwellian distribution is an oscillating source of free energy (a pump) which may stimulate certain ion Bernstein modes, their frequencies being near harmonics of Ωi. We here investigate the linear kinetic theory of the system. Linearization implies the parametric approximation of a strong constant pump. Application of the theory may be found in the earth's bow shock.

A large-scale potential field with an embedded smaller-scale force-free structure (∇ × B = αB) is studied in cylindrical geometry. We consider cases in which α goes continuously from a constant value α0 on the axis to zero at large r. Such a choice of α(r) produces fields which are realistic (few field reversals) but not completely stable. The MHD-unstable wavenumber regime is found. Since the considered equilibrium field exhibits a certain amount of magnetic shear, resistive instabilities can arise. The growth rates of the tearing mode in the limited MHD-stable region of º space are calculated, showing time-scales much shorter than the resistive decay time.

In this paper, nonlinear interaction of five monochromatic waves in a hot nonuniform streaming electron plasma has been presented. The method of formulation of the problem is based on the coupled mode theory. The wave–wave interaction phenomena have been analysed in the case of three longitudinal and two transverse waves. Furthermore, the presence of a stream velocity and its uniform gradient offers a generalization of the nonlinear interaction of an earlier work.

This paper reports on the use of forced magneto-acoustic oscillations to investigate the effect of a torsional hydromagnetic (Alfvén) wave pulse of moderate amplitude on the properties of a partially ionized afterglow helium plasma. Observations of the magnetic flux associated with the oscillations, measured at a number of frequencies, are used to determine radial density proffles and to provide estimates of plasma temperature. The torsional wave is shown to cause significant re-ionization of the plasma with no corresponding increase in the plasma temperature. The torsional wave is shown to cause significant re-ionization of the plasma with no corresponding increase in the plasma temperature. However, the presence of a number of energetic particles is evidenced by the production of a significant number of doubly charged helium ions.

A relativistic generalization of the Fokker–Planck formalism has been constructed. This is applied to the study of energy loss of high-energy electrons in plasma. Both the electron–electron and electron–ion scattering have been considered in a relativistic way. The expression obtained for the stopping power differs from that derived with the help of thermodynamic Green's function technique.

The stability of a self-consistent, large-amplitude, circularly polarized wave in a warm plasma is investigated. For perturbations to the system propagating normal to the plane of circular polarization, a dispersion relation is derived employing an expansion in the nonlinear wave amplitude and the momentum of the plasma particles in the plane of polarization. Instability results both in the absence and presence of a large-scale magnetic field with a growth rate of the order of the nonlinear wave amplitude.

The structure of transverse MHD shock waves in an initially partly ionized plasma is studied using a three-fluid model with collisional transport coefficients. This model includes the effects of non-equilibrium ionization and of ion velocity slip. A closed set of structure equations is obtained and it is shown that they have a saddle-point – saddle-point topology which prohibits direct integration. In distinction from previous MHD shock structure studies, it is not possible to reduce the number of variables in a realistic manner to allow direct integration, nor is it possible to use the method of matched asymptotic expansions. An iterative solution method is presented in this paper, based on a detailed analysis of the integral curve topology.

The structure of transverse MHD shock waves in a partly ionized hydrogen plasma is studied using a three-fluid model with collisional transport coefficients developed in Part 1. The morphology of the various sublayers in the shock front is analyzed in detail and it is shown that strong shock waves have a characteristic viscous structure. Weak to moderate strength shock waves display a resistive structure in which the enhanced transverse resistivity due to ion-slip plays a significant role, leading to a pronounced peak in the ion temperature profile. Calculated shock structure profiles are also compared with experimental temperature data. Results in the form of tables and figures are presented for shock waves with fast Mach number ranging from 1–10 in hydrogen plasma with initial degree of ionization ranging from 5–100%.

The plasma response to electrostatic travelling wave packets with a slowly varying envelope is investigated, including dynamical friction between electrons and ions. A kinetic diffusion equation and, therefrom, a new set of macroscopic equations is derived which includes current and magnetic field generation due to friction and wave momentum transfer.

A nonlinear Alfvén wave structure with axial symmetry about the line of force of an ambient magnetic field is presented. The solitary wave forms a ‘ring’ shaped waveguide along the magnetic field line.

A brief review of resonance cones in magnetized plasmas and their relationship with guided wave modes in bounded plasmas is given. It is shown that these two concepts are related mathematically by a Watson transformation, and physically by being complementary descriptions of waves in a warm bounded plasma. A detailed summary of the complementary nature of these two wave descriptions is given.

Propagation of electron-acoustic waves in a strongly nonlinear magnetoplasma with two ion species is investigated. The presence of the second ion component affects the dynamics of these solitary waves in a variety of ways. Besides solitons, supersonic holes (density depressions) are produced by sufficiently large- amplitude perturbations. Heavier and hotter ions are more favourable to the holes. Applications of the present investigations to space plasmas are pointed out.

Reid and Laing recently conjectured on the general behaviour of resistive force- free magnetic fields in a slab model following a numerical study. However, the basic properties of resistive force-free magnetic fields had been established previously. We use and extend some results from the previous work to show that the conjecture of Reid and Laing is incorrect. A general analytic treatment of the problem provides the correct physical properties that Reid and Laing were unable to deduce from their numerical solutions. A criticism is also given of the results presented in another numerical study treating cylindrical resistive forcefree magnetic fields, by the same authors.