The future utility of inertial confinement fusion requires a new driver. Successful experiments coupling laser energy to targets, and our understanding of fuel capsule behavior strongly suggest that a Laboratory thermonuclear source is attainable and power production may be considered if a suitable driver with high efficiency, high repetition rate, and most importantly, low capital cost, can be identified. No adequate driver exists today; however, the krypton fluoride laser holds great promise (Rosocha et al. 1986). By the end of this decade, driver development can be brought to the point that a technically justifiable choice can be made for the future direction of ICF.

Recent experiments to study the laser driven compression of CH shell targets and the effects of increasing aspect ratio using x-ray shadowgraph techniques are described. This work has been carried out at the Rutherford Appleton Laboratory's Central Laser Facility with 12 beam, 0·53 μm, 1·0 ns irradiation. X-ray shadowgraphy techniques have been used with a frame time of ∼100ps and spatial resolution of 5 to lOμm to obtain density profiles for the compressed targets. A systematic study of 150–200 μm targets with aspect ratios from ∼7 to ∼20 has been performed. The x-ray shadowgraphy techniques used are described, results in the form of x-radiographs presented and a discussion of preliminary results given.

In this paper we propose the coherent amplification of gamma radiation of a system of parapositronium atoms. The nonlinear optics of positronium media is suggested. The induced annihilation transitions for the electron-positron plasma are compared with those of the positronium medium. It is suggested in this paper that the Bose–Einstein condensation could play a crucial role in the estimation of the induced annihilation of electron-positron pairs for dense (n ≳ 1016cm−3) and cold (T ≲ 104 °K) positronium systems. The calculated effects of the induced positron-electron decays might be observed in astrophysical objects such as pulsars, white dwarf stars etc. Furthermore, these transitions might play an important role in Klein–Alfven cosmology. Finally, with the further advancement of the positron technology, a gamma ray laser may be constructed.

This was the first international meeting for unclassified research worldwide on X-ray lasers. There were 86 participants from 10 countries. It was organized most perfectly in the French Alps just before the end of the skiing season by Pierre Jaegle (Universite Paris-Sud, Orsay) who himself may be considered as one of the first, in the field of X-ray lasers. Jeagle et al. published, in 1971, a paper on the extraordinary increase of the 117 angstrom aluminium lines when a target was irradiated by laser and a comparison with cases emitted from different volumes. His result was highlighted in 1973 by Benjamin Lax and Art Guenther (1974): ‘The most definitive evidence of non-equilibrium population of excited atomic states in a laser-produced plasma was obtained by Jaegle et al. at the University of Paris in Orsay’.