From flat-panel televisions to thermonuclear fusion for energy production, plasmas currently have numerous and wide applications in sciences and industry. A diversity of plasma diagnostics is available to physicists and engineers to measure and control plasma parameters. Among them, the Langmuir probe is the most inexpensive and most popular instrument and method. The Langmuir probe is a small electrode which is submerged in plasma in order to measure the probe current-voltage characteristic. The same characteristic is processed further to derive the electron and ion concentration, the electron distribution function, and the plasma potential at the probe location. Langmuir probe diagnostics afford rapid measurements of the electron distribution function and plasma potential at a good time resolution, 10-8 seconds in a wide range of plasma densities 10+3 - 10+14 cm-3, and the electron energy from the room temperature to hundreds of electron-volts - qualities which are essential for researchers. In view of these facts, Langmuir probe diagnostics are applied very frequently to measuring plasma parameters. This book will be useful in teaching plasma diagnostics to undergraduate and graduate students in plasma physics courses. And it will also serve as a practical reference manual for physicists and engineers working in the growing area of plasma physics. The reader of this book will learn what kind of plasma parameters the Langmuir probe can measure, how to develop the probe diagnostics for specific cases, and how the probe data obtained should be processed to deduce reliable plasma parameters. In this book, the reader can find not only the basic physics information important to understanding the principles of probe operation, but also how the "real" probe disturbs plasma, and how it is possible to reconstruct undisturbed plasma parameters with available probe data.

This unified introduction provides the tools and techniques needed to analyze plasmas and connects plasma phenomena to other fields of study. Combining mathematical rigor with qualitative explanations, and linking theory to practice with example problems, this is a perfect textbook for senior undergraduate and graduate students taking one-semester introductory plasma physics courses. For the first time, material is presented in the context of unifying principles, illustrated using organizational charts, and structured in a successive progression from single particle motion, to kinetic theory and average values, through to collective phenomena of waves in plasma. This provides students with a stronger understanding of the topics covered, their interconnections, and when different types of plasma models are applicable. Furthermore, mathematical derivations are rigorous, yet concise, so physical understanding is not lost in lengthy mathematical treatments. Worked examples illustrate practical applications of theory and students can test their new knowledge with 90 end-of-chapter problems.

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 102. Space plasma measurements are conducted in a hostile, remote environment. The art and science of measurements gathered in space depend therefore on unique instrument designs and fabrication methods to an extent perhaps unprecedented in experimental physics. In-situ measurement of space plasmas constitutes an expensive, unforgiving, and highly visible form of scientific endeavor.

The electric probe has long been used as a fundamental diagnostic tool for measuring the local properties of a plasma. Since Langmuir first developed the electric-probe technique in 1924, probes have been used to measure electron densities and temperatures in a wide variety of gaseous ionized media, such as electric discharges, afterglows, ionizing shock waves, flames, MHD, and plasma-jet flows, reentry vehicle flow fields, and atmospheric and space plasmas. The first systematic account of modern theories of electriC-probe behavior was given by Chen (1965), who also provided practical information on experimental techniques. A subsequent survey by Swift and Schwar (1970), which was representative of results contained in the literature through 1969, included additional information on some of the modern theories and on practical details of probe utilization. The purpose of this volume is to supplement the previously mentioned two works by providing an account of a large body of the up-to-date informa tion available on electric probes, particularly in the areas of transitional and continuum-flow phenomena, and by offering, for all domains of probe appli cation, a critical appraisal of the more significant probe theories and experi mental investigations in the literature.

TO THE SECOND EDITION In the nine years since this book was first written, rapid progress has been made scientifically in nuclear fusion, space physics, and nonlinear plasma theory. At the same time, the energy shortage on the one hand and the exploration of Jupiter and Saturn on the other have increased the national awareness of the important applications of plasma physics to energy production and to the understanding of our space environment. In magnetic confinement fusion, this period has seen the attainment 13 of a Lawson number nTE of 2 x 10 cm -3 sec in the Alcator tokamaks at MIT; neutral-beam heating of the PL T tokamak at Princeton to KTi = 6. 5 keV; increase of average ß to 3%-5% in tokamaks at Oak Ridge and General Atomic; and the stabilization of mirror-confined plasmas at Livermore, together with injection of ion current to near field-reversal conditions in the 2XIIß device. Invention of the tandem mirror has given magnetic confinement a new and exciting dimension. New ideas have emerged, such as the compact torus, surface-field devices, and the EßT mirror-torus hybrid, and some old ideas, such as the stellarator and the reversed-field pinch, have been revived. Radiofrequency heat ing has become a new star with its promise of dc current drive. Perhaps most importantly, great progress has been made in the understanding of the MHD behavior of toroidal plasmas: tearing modes, magnetic Vll Vlll islands, and disruptions.

Throughout most of the twentieth century, electric propulsion was considered the technology of the future. Now, the future has arrived. This important new book explains the fundamentals of electric propulsion for spacecraft and describes in detail the physics and characteristics of the two major electric thrusters in use today, ion and Hall thrusters. The authors provide an introduction to plasma physics in order to allow readers to understand the models and derivations used in determining electric thruster performance. They then go on to present detailed explanations of: Thruster principles Ion thruster plasma generators and accelerator grids Hollow cathodes Hall thrusters Ion and Hall thruster plumes Flight ion and Hall thrusters Based largely on research and development performed at the Jet Propulsion Laboratory (JPL) and complemented with scores of tables, figures, homework problems, and references, Fundamentals of Electric Propulsion: Ion and Hall Thrusters is an indispensable textbook for advanced undergraduate and graduate students who are preparing to enter the aerospace industry. It also serves as an equally valuable resource for professional engineers already at work in the field.