Our understanding of elementary processes in plasmas has been increasing dramatically over the last few years. The development of various swarm techniques, such as the temperature variable selected ion flow tube or the selected ion flow drift tube, has provided the prerequisite for detailed investigations into ion molecule reactions both in binary and three body collisions, and the mechanisms of many reactions are now understood quite satisfactorily. This information could not have been obtained without a detailed knowledge of the transport phenomena involved. Some of these, such as the internal-energy distribution of drifting ions, have only very recently been tackled both theoretically and experimentally; a consistent model is now being developed. As the interactions between the various branches of swarm research have become more and more intense, the most obvious thing to do was putting together a review on the present state of this subject, which is the aim of this book.

The present volume contains the texts of the invited talks delivered at the Sev enth International Conference on Recent Progress in Many-Body Theories held at the University of Minnesota during the period August 26-31, 1991. The proceedings of the Fourth Conference (Oulu, Finland, 1987) and Fifth Conference (Arad, Israel, 1989) have been published by Plenum as the first two volumes of this series. Papers from the First Conference (Trieste, 1978) comprise Nuclear Physics volume A328, Nos. 1, 2. The Second Conference (Oaxtepec, Mexico, 1989) was published by Springer-Verlag as volume 142 of "Lecture Notes in Physics," entitled "Recent Progress in Many Body Theories." Volume 198 of the same series contains the papers from the Third Conference (Altenberg, Germany, 1983). These volumes are intended to cover a broad spectrum of current research topics in physics that benefit from the application of many-body theories for their elucidation. At the same time there is a focus on the development and refinement of many-body methods. One of the major aims of the conference series has been to foster the ex change of ideas among physicists working in such diverse areas as nucleon-nucleon in teractions, nuclear physics, astronomy, atomic and molecular physics, quantum chem istry, quantum fluids, and condensed matter physics. The present volume contains contributions from all of these areas.

Presents a unified theory of nuclear structure and nuclear reactions using the language of quantum electrodynamics, Feynman diagrams.