The last decade has seen dramatic progress in the development of devices for producing mu1ticharged ions. Indeed it is now pos sible to produce any charge state of any ion right up through 92 fully-stripped uranium (U +). Equally dramatic progress has been achieved in the energy range of the available ions. As an example, fully-stripped neon ions have been produced in useable quantities with kinetic energies ranging from a few ev to more than 20 Gev. Interest in the atomic physics of multicharged ions has grown apace. In the fusion program, the spectra of these ions is an im portant diagnostic tool. Moreover the presence of mu1ticharged ions presents a serious energy loss mechanism in fusion devices. This fact has motivated a program to study the collision mech anisms involved. In another area, mu1ticharged ions are present in the solar corona and the interstellar medium and knowledge of their collision properties and spectra is essential to understand ing the astrophysics. Other possible applications are to x-ray lasers and heavy ion inertial fusion. On a more fundamental level, new possibilities for testing quantum electrodynamics with mu1ti charged ions have emerged.

The progress in the physics of highly-ionized atoms since the last NATO sponsored ASI on this subject in 1982 has been enormous. New accelerator facilities capable of extending the range of highly-ionized ions to very high-Z have come on line or are about to be completed. We note particularly the GANIL accelerator in Caen, France, the Michigan State Superconducting Cyclotrons in East Lansing both of which are currently operating and the SIS Accelerator in Darmstadt, FRG which is scheduled to accelerate beam in late 1989. Progress i~ low-energy ion production has been equally dramatic. The Lawrence Livermore Lab EBIT device has produced neon-like gold and there has been continued improvement in ECR and EBIS sources. The scientific developments in this field have kept pace with the technical developments. New theoretical methods for evaluating relativistic and QED effects have made possible highly-precise calcula tions of energy levels in one-and two-electron ions at high-Z. The calculations are based on the MCDF method and the variational method and will be subject to rigorous experimental tests. On the experimental side, precision x-ray and UV measurements have probed the Lamb shift in the one and two electron ions up to Z=36 with increasing precision.

This book contains the invited lectures and contributed papers presented at the V International Conference on the Physics of Highly Charged Ions, which was held at the lustus-Liebig-Universi tat Giessen, 10-14 September 1990. This conference was the ftfth in a series -after Stockholm (1982), Oxford (1984), Groningen (1986) and Grenoble (1988) -to deal with a rapidly growing fteld, which comprises the spectroscopy of highly charged ions and their interactions with photons, electrons, atoms, ions, and solids. Most of the matter of the universe is in the ionized state. Investigations dealing with hot plasmas on earth have been greatly furthered by thermonuclear-fusion research. The increasing maturity of this programme has revealed the fundamental role of highly charged ions in fusion plasmas. Today, it is clear that a detailed knowledge of the production mechanisms of highly charged ions and their interactions with other plasma constituents is an important prerequisite for a better understanding of the microscopic and macroscopic plasma properties. The study of highly charged ions involves various branches of physics. It was the aim of the conference to bring together physicists working in atomic collisions and spectroscopy, in plasma physics and astrophysics, as well as in solid-state and ion-source physics. About 220 scientists from 20 nations attended the conference, indicating the strong worldwide interest and the vital ity of research in this fteld.

An introduction to the physics of highly excited, easily perturbed or interacting atoms. Covers Rydberg states, quantum defect theory, atomic f-values, centrifugal barrier effects, autoionisation, inner shell and double excitation spectra, K-matrix theory, atoms in high laser fields, statistical methods, quantum chaos, and atomic effects in solids.

Recent years have seen a growing interest in the effects of relativity in atoms, molecules and solids. On the one hand, this can be seen as result of the growing awareness of the importance of relativity in describing the properties of heavy atoms and systems containing them. This has been fueled by the inadequacy of physical models which either neglect relativity or which treat it as a small perturbation. On the other hand, it is dependent upon the technological developments which have resulted in computers powerful enough to make calculations on heavy atoms and on systems containing heavy atoms meaningful. Vector processing and, more recently, parallel processing techniques are playing an increasingly vital role in rendering the algorithms which arise in relativistic studies tractable. This has been exemplified in atomic structure theory, where the dominant role of the central nuclear charge simplifies the problem enough to permit some prediction to be made with high precision, especially for the highly ionized atoms of importance in plasma physics and in laser confinement studies. Today's sophisticated physical models of the atom derived from quantum electrodynamics would be intractable without recourse to modern computational machinery. Relativistic atomic structure calculations have a history dating from the early attempts of Swirles in the mid 1930's but continue to provide one of the primary test beds of modern theoretical physics.