Radiative Processes in Astrophysics


Book Description

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 Radiative Processes


Book Description

Atomic Radiative Processes provides a unified treatment of the theory of atomic radiative processes. Fourier transforms are used to obtain solutions of time-dependent Schrödinger equations, and coupled differential equations are transformed to coupled linear equations that in most cases can be readily solved. This book consists of nine chapters and begins with an overview of some of the properties of the classical field and its interaction with particles, focusing on those aspects needed for a better understanding of quantum theory. The Hamiltonian formalism is used to quantize the field, and the density of states of the radiation field is considered. The following chapters focus on a few Fourier transform techniques and their application to such areas as coherence properties of the field and amplitude and intensity correlations; the theory of angular momentum; the properties of irreducible tensors; quantization of the radiation field; and photon states. The interaction of a two-level atom with single modes of the radiation field is also discussed, along with spontaneous emission and decay processes; the evolution of coupled atomic states; the frequency distribution of emitted radiation; and radiative excitation and fluorescence. This monograph is intended for students and researchers in pure and applied physics.




An Introduction to the Atomic and Radiation Physics of Plasmas


Book Description

Plasmas comprise more than 99% of the observable universe. They are important in many technologies and are key potential sources for fusion power. Atomic and radiation physics is critical for the diagnosis, observation and simulation of astrophysical and laboratory plasmas, and plasma physicists working in a range of areas from astrophysics, magnetic fusion, and inertial fusion utilise atomic and radiation physics to interpret measurements. This text develops the physics of emission, absorption and interaction of light in astrophysics and in laboratory plasmas from first principles using the physics of various fields of study including quantum mechanics, electricity and magnetism, and statistical physics. Linking undergraduate level atomic and radiation physics with the advanced material required for postgraduate study and research, this text adopts a highly pedagogical approach and includes numerous exercises within each chapter for students to reinforce their understanding of the key concepts.




Radiative Processes in Atomic Physics


Book Description

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.




Radiative Processes in High Energy Astrophysics


Book Description

This book grew out of the author’s notes from his course on Radiative Processes in High Energy Astrophysics. The course provides fundamental definitions of radiative processes and serves as a brief introduction to Bremsstrahlung and black body emission, relativistic beaming, synchrotron emission and absorption, Compton scattering, synchrotron self-compton emission, pair creation and emission. The final chapter discusses the observed features of Active Galactic Nuclei and their interpretation based on the radiative processes presented in the book. Written in an informal style, this book will guide students through their first encounter with high-energy astrophysics.




Atomic and Molecular Radiative Processes


Book Description

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.




Radiation Trapping in Atomic Vapours


Book Description

Radiation can be absorbed and re-emitted many times in atomic vapors before it reaches the boundaries of the container encasing the vapor. This effect is known as radiation trapping. It plays an important role practically everywhere atomic vapors occur, whether in spectroscopy, gas lasers, atomic line filters, the determination of atomic lifetimes, measurements of atomic interaction potentials, or electric discharge lamps. This book is the first to assemble all of the information necessary to handle practical problems related to radiation trapping, and it emphasizes both physical insights and mathematical methods. The introduction reviews resonance radiation and collision processes in atomic vapors. This is followed by detailed explanations of the physical effects and mathematical methods for various types of problems (e.g., with or without saturation, particle diffusion, reflecting cell walls). The last part of the book describes the applications of these methods to a variety of practical problems, such as cross-section measurements and the design of discharge lamps.




The Atmosphere and Climate of Mars


Book Description

This volume reviews all aspects of Mars atmospheric science from the surface to space, and from now and into the past.




Atomic Spectroscopy and Radiative Processes


Book Description

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.




Physical Processes in Radiation Biology


Book Description

Physical Processes in Radiation Biology covers the proceedings of an International Symposium on Physical Processes in Radiation Biology, held at the Kellogg Center for Continuing Education, Michigan State University on May 6-8, 1963, sponsored by the U.S. Atomic Energy Commission. The symposium aims to address the core problems of radiation biology concerning the absorption, distribution, and utilization of high energy packets in biological systems. This book is composed of 21 chapters, and begins with an introduction to the absorption, excitation, and transfer processes in molecular solids. The subsequent chapters discuss the nature of exciton processes; the mechanisms of charge transport in biological materials; the interactions of fast and slow electrons with model systems; the importance of liquid structures in determining the development of radiation damage; and the nature of the metastable species formed. The concluding chapters explore the importance of charge migration in energy transfer processes in different biological systems and the significance of higher excited levels in charge migration and energy transfer. These chapters also describe the nature of the hydration of electrons and protons in aqueous systems. This book will be of great value to radiation biologists, biophysicists, physical chemists, and physicists.