Nonequilibrium Transport Processes in Weakly Ionized Plasmas


Book Description

The nonlocal electron and ion transport processes in weakly ionized plasmas are studied. The goal is to consider the most general ordering when the mean free path for the charged species is arbitrary with respect to the characteristic length scale in plasma and characteristic frequency is arbitrary with respect to collision frequency. For electron component, we present a rather general method of solving the Boltzmann equation, which is based on the expansion of the total distribution function (DF) in the series of the eigenfunctions of the collision operator. The coefficients in this expansion are related to the different velocity moments of the distribution function. The expansion of the DF in terms of the eigenfunctions of the collision operator is equivalent to the expansion in the series of a parameter 3 which is a measure of spatial and temporal uniformity 3=kl;hsp sp="0.167"3=w /nrp post="par" . As this parameter increases (the mean free path becomes larger and/or the characteristic length of plasma inhomogeneity decreases and/or characteristic frequency of plasma inhomogeneity increases), the larger number of terms should be included in the expansion procedure and in the limiting collisionless case all harmonics (all moments) must be included. The obtained infinite system of equations for the expansion coefficients is solved in terms of the continued fraction representation. We have calculated transport coefficients of a weakly ionized plasma that describe the relaxation processes for the arbitrary uniformity parameter 3 . In this case the transport coefficients become integro-differential operators acting on the lower moments (density, temperature, mean velocity, and external fields). As an example we consider the anomalous absorption of the electromagnetic wave by a weakly ionized plasma or anomalous skin effect. Unlike.




Nonequilibrium Transport Processes in Weakly Ionized Plasmas


Book Description

The nonlocal electron and ion transport processes in weakly ionized plasmas are studied. The goal is to consider the most general ordering when the mean free path for the charged species is arbitrary with respect to the characteristic length scale in plasma and characteristic frequency is arbitrary with respect to collision frequency. For electron component, we present a rather general method of solving the Boltzmann equation, which is based on the expansion of the total distribution function (DF) in the series of the eigenfunctions of the collision operator. The coefficients in this expansion are related to the different velocity moments of the distribution function. The expansion of the DF in terms of the eigenfunctions of the collision operator is equivalent to the expansion in the series of a parameter 3 which is a measure of spatial and temporal uniformity 3=kl;hsp sp="0.167"3=w /nrp post="par" . As this parameter increases (the mean free path becomes larger and/or the characteristic length of plasma inhomogeneity decreases and/or characteristic frequency of plasma inhomogeneity increases), the larger number of terms should be included in the expansion procedure and in the limiting collisionless case all harmonics (all moments) must be included. The obtained infinite system of equations for the expansion coefficients is solved in terms of the continued fraction representation. We have calculated transport coefficients of a weakly ionized plasma that describe the relaxation processes for the arbitrary uniformity parameter 3 . In this case the transport coefficients become integro-differential operators acting on the lower moments (density, temperature, mean velocity, and external fields). As an example we consider the anomalous absorption of the electromagnetic wave by a weakly ionized plasma or anomalous skin effect. Unlike.




Transport Processes in Multicomponent Plasma


Book Description

Transport Processes in Multicomponent Plasma is a revised and updated version of the original Russian edition. The book examines transport phenomena in multicomponent plasma and looks at important issues such as partially ionized gases, molecular gas mixtures and methods of calculating kinetic coefficients. It makes a logical progression from simpler to more general problems, and the results presented in the book may be used to calculate the kinetic coefficients of plasma in electric and magnetic fields. The author concludes by describing several practical applications such as electrical conductivity and Hall's effect in MHD-generators. Transport Processes in Multicomponent Plasma will be of interest to advanced students and specialized researchers working in various aspects of plasma physics, including both cold plasmas for industrial research and high temperature plasmas in fusion.







Transport Phenomena in Partially Ionized Plasma


Book Description

Transport phenomena in plasmas are the relatively slow processes of particle momentum and energy transport systems in a state of mechanical equilibrium. In contrast to neutral gases, these phenomena in plasmas are greatly influenced by self-consistent fields, in particular electric fields. These can produce particle and energy fluxes, in addition to those generated by the inhomogeneity of the plasma composition and temperature. As a result, the physical effects accompanying transport phenomena in plasmas are far more numerous and complicated than those in neutral gases, and the solution of corresponding problems is more difficult. The effects, however, are usually far more interesting and sometimes surprising. This book presents a systematic survey and analysis of the main mechanisms of transport phenomena in plasma and gives examples of gradually increasing complexity to illustrate these mechanisms and the relationships between them. The author pays special attention to the analysis of experimental measurements and considers the relevant processes analytically as well as qualitatively. The majority of problems dealt with in this book are of considerable practical interest, and the phenomena described often determine the main characteristics of processes and devices. Transport Phenomena in Partially Ionized Plasma will be of interest to researchers who need to know the properties of real, specific systems, as well as to engineers and advanced students in the physics of plasmas, semiconductors, various types of gas discharges and the ionosphere.




Nonequilibrium Effects in Ion and Electron Transport


Book Description

This volume presents the contributions of the participants in the Sixth International Swarm Seminar, held August 2-5, 1989, at the Webb Institute in Glen Cove, New York. The Swarm Seminars are traditionally held as relatively small satellite conferences of the International Conference on the Physics of Electronic and Atomic Collisions (ICPEAC) which occurs every two years. The 1989 ICPEAC took place in New York City prior to the Swarm Seminar. The focus of the Swarm Seminars has been on basic research relevant to understanding the transport of charged particles, mainly electrons and ions, in weakly ionized gases. This is a field that tends to bridge the gap between studies of fundamental binary atomic and molecular collision processes and studies of electrical breakdown or discharge phenomena in gases. Topics included in the 1989 seminar ranged the gamut from direct determinations of charged-particle collision cross sections to use of cross sections and swarm parameters to model the behavior of electrical gas discharges. Although the range of subjects covered was in many respects similar to that of previous seminars, there was an emphasis on certain selected themes that tended to give this seminar a distinctly different flavor. There was, for example, considerable discussion on the meaning of "equilibrium" and the conditions under which nonequilibrium effects become important in the transport of electrons through a gas.




Transport Processes in Plasmas: Classical transport


Book Description

Existing textbooks on plasma physics usually contain only a minor contribution devoted to plasma transport. The aim of Transport Processes in Plasmas'' is to provide a comprehensive and unified presentation of the transport theory in plasmas. This subject is of great importance in general statistical and plasma physics; moreover, it constitutes a keystone in the thermonuclear fusion programme as well as in astro- and geophysics. The subject is presented here by unified concepts, methods and notations. The contents are strongly embedded in a general framework of theoretical physics, appealing to modern Hamiltonian mechanics, kinetic theory, non-equilibrium thermodynamics, etc. The necessary concepts from these disciplines are briefly but completely explained, making the two volumes a self-contained text. Plasma transport theory can be characterised as a truly interdisciplinary activity, and several chapters are included containing the important concepts of these peripheral fields, briefly and completely. Many new features are introduced in those two volumes.




Physics of Non-equilibrium Plasmas


Book Description

This book deals with the physics of low temperature plasmas of atomic and molecular gases. Several diagnostic methods for nonequilibrium plasma are described. The relevant elementary processes governing the kinetics and transport of atomic and chemically active molecular plasmas are discussed and numerical models of plasmas aimed at systematically solving MHD-equations are also presented. Intended for use by scientists and engineers active in various fields of low-temperature plasma physics, this book is also suitable for teachers and students at pre- and postgraduate level. In chapter 1 general problems of the elementary physics of plasma are considered and the principal ideas relating to plasma properties are given. In chapter 2 the principles which form the basis of atomic and molecular spectra radiated by a plasma are briefly described. Chapter 3 reviews experimental material associated with the peculiarities of molecular excitation processes in nonequilibrium low-temperature plasma. In chapter 4 a number of problems related to the technique and methods of spectroscopy are considered. Chapter 5 presents experimental material gained from studying the peculiarities of molecular excitation spectra from low-pressure gas discharges and describes diagnostics for nonequilibrium chemically active plasma. In chapter 6 the problems of mathematical modeling of equilibrium plasma in arcs, microwave and optical discharges are analyzed. In chapter 7, a theoretical description of nonequilibrium plasma in electrical arcs, microwave and radio-frequency discharges based on two-temperature approximation of the plasma parameters is offered. Chapter 8 presents a detailed case-study on the transport and excitation of a magnetized plasma of intermediate electron density. Several diagnostic techniques and models introduced in earlier chapters are used to obtain information on plasma properties.




Nonequilibrium Effects in Ion and Electron Transport


Book Description

This volume presents the contributions of the participants in the Sixth International Swarm Seminar, held August 2-5, 1989, at the Webb Institute in Glen Cove, New York. The Swarm Seminars are traditionally held as relatively small satellite conferences of the International Conference on the Physics of Electronic and Atomic Collisions (ICPEAC) which occurs every two years. The 1989 ICPEAC took place in New York City prior to the Swarm Seminar. The focus of the Swarm Seminars has been on basic research relevant to understanding the transport of charged particles, mainly electrons and ions, in weakly ionized gases. This is a field that tends to bridge the gap between studies of fundamental binary atomic and molecular collision processes and studies of electrical breakdown or discharge phenomena in gases. Topics included in the 1989 seminar ranged the gamut from direct determinations of charged-particle collision cross sections to use of cross sections and swarm parameters to model the behavior of electrical gas discharges. Although the range of subjects covered was in many respects similar to that of previous seminars, there was an emphasis on certain selected themes that tended to give this seminar a distinctly different flavor. There was, for example, considerable discussion on the meaning of "equilibrium" and the conditions under which nonequilibrium effects become important in the transport of electrons through a gas.