An analysis is made of the equation of state problems in inertial confinement fusion. After reviewing the need for compression for inertial confinement fusion along the lines of the classical self similarity model which is derived in a modified way with indications of the equation of state, the problems of the central core ignition are examined with respect to the equation of state. A basic difficulty is elaborated in the ‘scape goat diagram’. After describing alternative compression schemes such as non-linear force and cannon ball, the two temperature equation of state is developed with electronic and ionic contributions following the ideal gas, the Debye-Grüneisen equation of state, the solid-gas interpolation and the SESAME tables. A remarkable discrepancy for the isothermal diagrams is shown between the general result and the result based on the earlier McCarthy–Kalitkin scheme.

Both broad and narrow band Nd glass laser beams with energies 1 to 3 joules and pulse width 150 ps were used in aluminium plane target experiments at laser irradiances 1 to 3 × 10 14 W cm −2 on target surfaces. The incident laser beams were angled at 0°, 7·2°, 14·4°, 21·6°, 28·8°, 36°, 43·2° to the target surface normal and the polarization was perpendicular or parallel to the incident plane (s or p polarization). The experiments showed that the maximum resonance absorption occurred near to incident angles of about 9° to 10° and the broadband resonance absorption was slightly smaller than that of the narrowband. At large incident angles the broadband absorption was larger than that of the narrowband.

The physical mechanisms of thermal flux limitation and thermal conduction inhibition in laser plasmas are analyzed. A numerical calculation accounting for the non-negative electron distribution function and pressure gradient has been given.

The longitudinal dielectric response function of a relativistic gas consisting of charged bosons together with the corresponding antiparticles is obtained in the random phase approximation. The theory is renormalized and an analysis of the mode structure and damping properties of the plasma is carried out.

Experimental results are presented on the focusing of an intense microsecond relativistic electron beam. The beam is generated in a high-voltage quasi-planar diode (E = 600–800 keV, τ = 3–5 μsec). It is then magnetically – focused by longitudinal injection into a magnetic mirror. The total energy of the beam is about 50 kJ. The focusing chamber is filled with argon under a pressure varying from 3 × 10−5 to 1 torr. The results include investigations of beam focusing under various conditions, the dynamics of the return current in the plasma as well as the influence of the reflected beam electrons on the operation of the accelerator diode. A 20-fold focused beam with a 4 cm diameter, 46 kJ energy content, and current density up to 3 kA/cm2 was obtained.

We show that the thermal transport in laser produced plasmas can be inhibited due to the outward plasma blow-off which is in the opposite direction to the inward heat transport. A simple model is proposed in which the steady state heat transfer equation, including the convective term for a point heat source, is solved. A simple analytical expression for the ratio of effective to classical conductivity depending on the blow-off velocity is obtained. With this model, present experimental data on thermal transport can be qualitatively, but consistently described.

Attempts to accelerate and implode laser targets are hindered by the non-uniformities present in real laser beams. The effects of non-uniform illumination are ‘smoothed’ by thermal transport in the low density ablation plasma but amplified by the fluid instabilities (Rayleigh–Taylor) present in the high density accelerated material. In this paper the effects of different assumptions concerning the plasma thermal conductivity are analysed and the inclusion of the full fluid equations is shown to introduce oscillatory (acoustic) and growing (Rayleigh–Taylor) phenomena into the fluid response.

The radiation hydrodynamics of material layers for energy conversion of intense ion beams into black body radiation is investigated, both analytically and numerically. Conversion efficiency and hydrodynamic losses are the main topics. The basic scaling relations are derived and compared with computer simulations. Although the analysis is done for slab geometry, a generalization to converters of arbitrary shape and deposition geometry is outlined. The code MINIRA is briefly described. The influence of varying layer density, optical thickness and beam power on radiation emission as well as the effect of Bragg peak deposition are discussed in detail. High conversion efficiencies of more than 50% can be obtained provided that the converter is operated in the radiative regime. For typical beam intensities, this requires low-density layers. Another essential feature is supersonic heat transport which occurs in the radiative regime.

The following corrections should be noted:

p. 451

p. 457

with