Strong ion coupling effects could play an important role in laser–and particle beam–compressed ICF layered targets. Some light is shed on these effects by examining structure and pair correlation functions calculated from some of the well known strongly coupled plasma approximation schemes.

The change of the energetic quantum levels of electrons in atoms or ions within plasma due to the electrostatic energy of the Debye sphere, is discussed on the basis of an electrostatic quantum model which permits an immediate, and therefore an integrated, inclusion of the Debye screening. The resulting Debye field leads to an alternative (temperature dependent) formulation of the Inglis-Teller Stark merging of spectral lines. In the new model the drowning of lines gives values closer to the Inglis-Teller limit than values given by the quantum approximation of the hydrogenic model. The straightforward calculation of the polarization shift based on the new model is closest to the experimental values and is between the very low values given by the semiclassical approach and the too high values given by the quantum approach of the hydrogenic effective charge model.

Inertial Confinement Fusion (ICF) research has been extensively advanced with the increase of the focusable power on target by the development of glass laser technology and its higher harmonic generation (Yamanaka & Kato et al. 1981) and by CO2 lasers (Yamanaka & Nakai et al. 1981) which cover the wavelength range from 10 μm to 0·25 μm and power densities up to 1017 W/cm2. With improved understanding of the implosion in the fuel pellet, breakeven conditions, or ignition, are expected to be achieved within the 1980's with the construction of lasers in the region of 100 kJ and 100 TW output power.

A one-dimensional, time-dependent fluid code is presented that numerically solves the hydrodynamic equations together with the wave equation for a picosecond pulse laser heated plasma. The laser light absorption by classical inverse bremsstrahlung and the ponderomotive force are evaluated self-consistently from the computed electromagnetic field quantities. At oblique incidence of p-polarized 1·054 μm laser radiation the resonant electric field is saturated by plasma wave convection through the nonlinear density profile steepening prior to wave breaking.

A computer kinetics model has been developed to predict the steady state behaviour of e-beam-pumped KrF lasers. The model can be used to calculate species densities, gain, loss and laser efficiency. Close agreement is obtained between the model predictions and a wide range of experimental measurements of optical gain, loss, and laser efficiency as a function of e-beam pump power, taken at various laboratories.

An ‘effective Feynman diagram’ technique is introduced to obtain relations between the cross-sections of various atomic processes. In this paper the technique is used to obtain a simple relation between the cross-sections of electron impact excitation and resonant photon absorption. The method is important because calculations of complicated atomic wavefunctions are eliminated.