This book describes selected problems in contemporary spectroscopy in the context of quantum mechanics and statistical physics. It focuses on elementary radiative processes involving atomic particles (atoms, molecules, ions), which include radiative transitions between discrete atomic states, the photoionization of atoms, photorecombination of electrons and ions, bremsstrahlung, photodissociation of molecules, and photoattachment of electrons to atoms. In addition to these processes, the transport of resonant radiation in atomic gases and propagation of infrared radiation in molecular gases are also considered. The book subsequently addresses applied problems such as optical pumping, cooling of gases via laser resonance radiation, light-induced drift of gas atoms, photoresonant plasma, reflection of radio waves from the ionosphere, and detection of submillimeter radiation using Rydberg atoms. Lastly, topical examples in atmospheric and climate change science are presented, such as lightning channel glowing, emission of the solar photosphere, and the greenhouse phenomenon in the atmospheres of the Earth and Venus. Along with researchers, both graduate and undergraduate students in atomic, molecular and atmospheric physics will find this book a useful and timely guide.

This book offers advanced students and researchers an up-to-date quantum treatment of the interaction of atoms with electromagnetic radiation. Problems and solutions are used to develop concepts, terminology, and the principal results of the quantum theory of radiative processes in atoms. Concepts covered include: radiative transitions between discrete states in atomic systems, atomic photoprocesses involving free particles, coherent phenomena in radiative transitions, extensive treatment of line-broadening mechanisms, atoms in strong fields and theory of angular momentum.

This book describes the basic physical principles of atomic spectroscopy and the absorption and emission of radiation in astrophysical and laboratory plasmas. It summarizes the basics of electromagnetism and thermodynamics and then describes in detail the theory of atomic spectra for complex atoms, with emphasis on astrophysical applications. Both equilibrium and non-equilibrium phenomena in plasmas are considered. The interaction between radiation and matter is described, together with various types of radiation (e.g., cyclotron, synchrotron, bremsstrahlung, Compton). The basic theory of polarization is explained, as is the theory of radiative transfer for astrophysical applications. Atomic Spectroscopy and Radiative Processes bridges the gap between basic books on atomic spectroscopy and the very specialized publications for the advanced researcher: it will provide under- and postgraduates with a clear in-depth description of theoretical aspects, supported by practical examples of applications.

Radiative Processes in Astrophysics: This clear, straightforward, and fundamental introduction is designed to present-from a physicist's point of view-radiation processes and their applications to astrophysical phenomena and space science. It covers such topics as radiative transfer theory, relativistic covariance and kinematics, bremsstrahlung radiation, synchrotron radiation, Compton scattering, some plasma effects, and radiative transitions in atoms. Discussion begins with first principles, physically motivating and deriving all results rather than merely presenting finished formulae. However, a reasonably good physics background (introductory quantum mechanics, intermediate electromagnetic theory, special relativity, and some statistical mechanics) is required. Much of this prerequisite material is provided by brief reviews, making the book a self-contained reference for workers in the field as well as the ideal text for senior or first-year graduate students of astronomy, astrophysics, and related physics courses. Radiative Processes in Astrophysics also contains about 75 problems, with solutions, illustrating applications of the material and methods for calculating results. This important and integral section emphasizes physical intuition by presenting important results that are used throughout the main text; it is here that most of the practical astrophysical applications become apparent.

Atomic and Molecular Processes focuses on radiative and collisional processes involving atoms or molecules, including photoionization, elastic and inelastic scattering of electrons, energy loss by slow electrons, excitation, ionization, detachment, charge transfer, elastic scattering, and chemical reactions. The selection first offers information on forbidden and allowed transitions, including forbidden transitions in diatomic molecular spectra; forbidden transitions in crystals; calculations of atomic line strengths; and measurements of atomic transition probabilities. The book also ponders on photoionization processes, photodetachment, and high temperature shock waves. The manuscript elaborates on electronic and ionic recombination, elastic scattering of electrons, and the motions of slow electrons in gases. The book also evaluates the theory of excitation and ionization by electron impact; measurement of collisional excitation and ionization cross sections; and spectral line broadening in plasmas. The selection is a dependable reference for readers interested in atomic and molecular processes.

Sir David Bates celebrated his seventieth birthday on the 18th November 1986. To mark this event a conference was held in the David Bates building at The Queen's University of Belfast on the 17th and 18th November 1986. At this conference ex-students and colleagues of Sir David, who are acknowledged world experts in their field of research, gave in depth reviews of a particular area of atomic and molecular physics. This book on the conference presents a unique account of recent studies in atomic and molecular processes in a wide range of research fields. This volume is dedicated to Sir David by his friends as a token of their affection and respect. It is hoped that it will provide a useful summary of current research in atomic and molecular physics and that it will also show the great contribution which Sir David made to atomic and molecular physics. This conference was supported by the USAF European Office of Aerospace Research and Development who we wish to thank for their generous support. Arthur E. Kingston v CONTENTS Interstellar Cloud Chemistry Revisited 1 D.R. Bates Photo-ionisation of Atomic Oxygen . . . . . . . . . • • . • • • 29 M.J. Seaton The Formation of Complex Interstellar Molecules • • • • • . . .