Plasma

In recent years the significant progress in satellite-based observations of plasma states and associated electromagnetic phenomena in space has resulted in the accumulation of much evidence of various plasma instabilities. Today plasma instabilities are believed to be responsible for electromagnetic radiation as well as for many of the macroscopic dynamics of plasmas in space. Most students who begin to study plasma physics are intrigued by the unstable nature of plasmas compared with other states of matter; however, they often become frustrated because there are so many in­ stabilities. Such frustration explains in part why there is no textbook which treats this subject exclusively. A description of plasma instabilities in a systematic way is nontrivial and takes a pertinacious effort. This book is an attempt to provide a basic introduction on the subject and covers most of the important instabilities. However, the author must apologize for any omission of references to contributions of individuals who deserve more credit. The reader is assumed to have a general knowledge of plasma physics obtainable in an undergraduate course. The book is intended to be used as a reference text on the subject of plasma instabilities at the under­ graduate level as well as for a text in a special course in graduate school. Because the book is part of a series on physics and chemistry in space, emphasis is placed on plasma instabilities relevant in space plasmas.

A variety of nonlinear effects occur in a plasma. First, there are the wave­ steepening effects which can occur in any fluid in which the propagation speed depends upon the wave-amplitude. In a dispersive medium this can lead to classes of nonlinear waves which may have stationary solutions like solitons and shocks. Because the plasma also acts like an inherently nonlinear dielectric resonant interactions among waves lead to exchange of energy among them. Further, an electromagnetic wave interacting with a plasma may parametrically excite other waves in the plasma. A large-amplitude Langmuir wave undergoes a modulational instability which arises through local depressions in plasma density and the corresponding increases in the energy density of the wave electric field. Whereas a field collapse occurs in two and three dimensions, in a one-dimensional case, spatially localized stationary field structures called Langmuir solitons can result. Many other plasma waves like upper-hybrid waves, lower-hybrid waves etc.

This book is focused on the recent achievements in optimization and understanding of non-equilibrium plasma for gas conversion via plasma modeling and experimental work.

Authors: Wong, Chiow San, Mongkolnavin, Rattachat
SpringerBriefs in Applied Sciences and Technology