Atomic Collisions And Spectra

Atomic Collisions and Spectra provides an overview of the state of knowledge on atomic collision physics. The book grew out of lecture notes for a succession of courses at the University of Chicago in 1967-1979, which reported the new material as it was taking a definite form. It has been enriched since 1980, as the subject matured and continued to expand. The book is organized into four parts. Part A deals briefly with rather elementary items of general information. Part B then takes up in considerable detail those aspects of single-electron scattering whose mastery is essential for treating multielectron processes. Part C deals with multielectron processes with a residual—if often realistic—restriction, namely, that the multielectron interactions remain confined within a core region from which only a single electron escapes into alternative channels of a long-range field. Part D surveys studies of double (or multiple) escape of electrons from a core. The book is intended for multiple use as a graduate school text, a tool for independent study, or a reference for particular topics.

Problems after each chapter

This volume contains papers associated with the conference "Atomic Spectra and Collisions in External Fields II", that took place July 30-31 1987 at Royal Holloway and Beford New College. The first meeting of this name was held at the National Bureau of Standards in Gaithersburg, Maryland in 1984, and, if any tradition can yet be said to have been established in the series, it is that the proceedings be written after the conference. We hope thereby to preserve some impression of the discussions that took place, which in both cases were vigorous and unihibited. Both meetings happen to have convened in proximity to major developments in the field. At the time of the first conference, results of experimental measurements of dielectronic recombination in electron ion beams were beginning to appear. These showed large discrepancies with theoretical calculations, which were attributed to the effects of rather weak electric fields on the highly-excited states that mediate the recombination process. This conjecture gave rise to widespread concern in the plasma physics community that the representation of dielectronic recombination in existing plasma models, in which it plays an important role in energy and ionization balance, might be seriously in error due to neglect of the effects of electric and magnetic fields. The subject of field effects on recombination processes was thus a major focus of the 1984 meeting.

Introduction to the Theory of Atomic Spectra is a systematic presentation of the theory of atomic spectra based on the modern system of the theory of angular momentum. Many questions which are of interest from the point of view of using spectroscopic methods for investigating various physical phenomena, including continuous spectrum radiation, excitation of atoms, and spectral line broadening, are discussed. This volume consists of 11 chapters organized into three sections. After a summary of elementary information on atomic spectra, including the hydrogen spectrum and the spectra of multi-electron atoms, the reader is methodically introduced to angular momentum, systematics of the levels of multi-electron atoms, and hyperfine structure of spectral lines. Relativistic corrections are also given consideration, with particular reference to the use of the Dirac equation to determine the stationary states of an electron in an arbitrary electromagnetic field. In addition, the book explores the Stark effect and the Zeeman effect, the interaction between atoms and an electromagnetic field, and broadening of spectral lines. The final chapter is devoted to the problem of atomic excitation by collisions. This book is intended for advanced-course university students, postgraduate students and scientists working on spectroscopy and spectral analysis, and also in the field of theoretical physics.

"Excitation of Atomic Spectra provides a survey of the elementary processes of atomic collisions responsible for the formation of atomic spectra in the laboratory and astrophysical plasmas. It presents the usefull and rather simple approximate methods for calculation of cross-sections and gives a set of fitting formulas. Extensive tables list the cross-sections and rate coefficients for excitation and ionization of atoms and ions calculated by the code ATOM. A special appendix provides the formulas for the energy and transition matrix elements in the representation most convenient for computer calculations. The theory of spectral line broadening and its application to plasma spectroscopy is given. The general approach to the problem based on the methods of density matrix and quantum kinetic equation is also outlined."--BOOK JACKET.

"Perhaps the most controversial aspect of this volume is the number (V) assigned to the conference in this series. Actually, the first conference to be held under the title "Atomic Collisions in Solids" was held at Sussex University in England in 1969 and the second at Gausdal, Norway in 1971, which would logically make the conference held at Gatlinburg, Tennessee, U.S.A. in 1973 the third (III). However, the appearance of the proceedings of the 1971 Gausdal Conference (published by Gordon and Breach) bore the number IV. The reasoning behind this was that, in. fact, two previous conferences had been largely dedicated to the same subject area. The first of these was at Aarhus, Denmark in 1965 and the second in 1967 was held in Chalk River, Canada. Hence, the number V for the 1973 meeting."--Page v

In recent years, the impact of new experimental techniques (e.g., nuclear physics methods, availability of high-intensity light sources) as well as an increasing demand for atomic collision data in other fields of physics (e.g., plasma physics, astrophysics, laser physics, surface physics, etc.) have stimulated a renewed, strong interest in atomic collision research. Due to the explosive development of the various fields, scientists often even have dif ficulty in keeping up with their own area of research; as a result, the overlap between different fields tends to remain rather limited. Instead of having access to the full knowledge accumulated in other fields, one uses only the small fraction which at the moment seems to be of immediate importance to one's own area of interest. Clearly, many fruitful and stimulating ideas are lost in this way, causing progress to be made much more slowly than it could be. Atomic col lision physics is no exception to this rule. Although it is of basic interest to many other areas, it is mostly regarded merely as a (nonetheless important) tool by which to gain additional information.