The ion-acoustic solitons are investigated in three-component plasmas, whose constituents are electrons, positrons, and singly charged ions. It is found that the presence of the positron component in such a multispecies plasma can result in reduction of the ion-acoustic soliton amplitudes.

Dusty plasmas in a gas discharge often feature a stable void, i.e., a dust-free region inside the dust cloud. This occurs under conditions relevant to both plasma processing discharges and plasma crystal experiments. The void results from a balance of the electrostatic and ion drag forces on a dust particle. The ion drag force is driven by a flow of ions outward from an ionization source and toward the surrounding dust cloud, which has a negative space charge. In equilibrium the force balance for dust particles requires that the boundary with the dust cloud be sharp, provided that the particles are cold and monodispersive. Numerical solutions of the one-dimensional nonlinear fluid equations are carried out including dust charging and dust-neutral collisions, but not ion-neutral collisions. The regions of parameter space that allow stable void equilibria are identified. There is a minimum ionization rate that can sustain a void. Spatial profiles of plasma parameters in the void are reported. In the absence of ion-neutral collisions, the ion flow enters the dust cloud's edge at Mach number M=1. Phase diagrams for expanding or contracting voids reveal a stationary point corresponding to a single stable equilibrium void size, provided the ionization rate is constant. Large voids contract and small voids expand until they attain this stationary void size. On the other hand, if the ionization rate is not constant, the void size can oscillate. Results are compared to recent laboratory and microgravity experiments.

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PrefaceThe physics of complex plasma systems containing a colloid "macroscopic" particle component ("dust") is a rapidly emerging area at the forefront of the physics and chemistry of plasmas and gas discharges, space physics and astrophysics, and materials science and engineering. Complex plasma systems with nano-and microscopic particle inclusions is now a hot topic for many research areas. Such plasma systems present an excellent example of complex systems because of the many and varied constituents, and the space and time scales involved, with extensive interaction between them.In our decision to write this book, we were mostly motivated to introduce, in a systematic and easy-to-follow manner, our understanding of the fundamental physics and industrial applications of complex plasma systems. The recent progress in the field has been so remarkable that several novel directions and paradigms in complex plasma research have emerged. Therefore, we have decided to focus on the most important (as we see them) current topics, and new paradigms in the research on and applications of complex plasma systems. We also review the role of "dust" in laboratory plasmas and discuss various challenging applications of the nanoand micrometer-sized particles in high-tech industries. We systematically present the current state of research and the physical insights, including the advanced theoretical models and results of extensive computer simulations, complemented with the laboratory experiments specifically designed to elucidate the fundamental physics of complex plasmas. This book provides a broad perspective and opens up future development of this rapidly expanding field to interested researchers normally working in various areas. Even though the main attention in this book is given to the conditions relevant to the laboratory gas discharges and industrial plasma reactors, most of the fundamental concepts discussed here are also ... Vlll Physics and Applzcations of Complex Plasmasapplicable to space and astrophysical plasmas. A specialized and comprehensive description of the most recent theoretical, experimental, and modeling efforts to understand the unique properties of complex plasma systems, including the stability, dynamics, and self-organization of colloid particles and their associations, is given. Special attention is paid to the physical concepts and most recent technological advances in various industrial applications of the micrometer-and nano-sized particles. The first chapter introduces complex plasmas as a new and unusual state of matter with fascinating physical properties. Chapters 2 and 3 present the fundamentals of the theory of interactions of the colloid particles with ionized gases and experimental methods of production and diagnostics of complex plasmas. Topics important to the physics of strongly and weakly coupled particle-plasma. systems are discussed in the following three chapters. In Chapter 4, key attention is paid to the particle dynamic phenomena, as well as particle arrangement and stability ...

A plasma becomes quantum when the quantum nature of its particles significantly affects its macroscopic properties. To answer the question of when the collective quantum plasma effects are important, a proper description of such effects is necessary. We consider here the most common methods of description of quantum plasma, along with the related assumptions and applicability limits. In particular, we analyze in detail the hydrodynamic description of quantum plasma, as well as discuss some kinetic features of analytic properties of linear dielectric response function in quantum plasma. We point out the most important, in our view, fundamental problems occurring already in the linear approximation and requiring further investigation.