Fundamentals of Plasma Physics and Controlled Fusion

Abstract

Professor Kenro Miyamoto, already well known for his textbook Plasma Physics for Nuclear Fusion (MIT Press, Cambridge, MA, 1976; revised edition 1989), has now published a new book entitled Fundamentals of Plasma Physics and Controlled Fusion (Iwanami Book Service Center, Tokyo, 1997). To a large extent, the new book is a somewhat shortened and well reorganized version of its predecessor. The style, concise and matter of fact, clearly shows the origin of the text in lectures given by the author to graduate students. As announced by the title, the book is divided into two parts: the first part (about 250 pages) is a general introduction to the physics of plasmas, while the second, somewhat shorter, part (about 150 pages), is devoted to a description of the most important experimental approaches to achieving controlled thermonuclear fusion. Even in the first part, moreover, the choice of subjects is consistently oriented towards the needs of fusion research. Thus, the introduction to the behaviour of charged particles (particle motion, collisions, etc.) and to the collective description of plasmas is quite short, although the reader will get a flavour of all the most important topics and will find a number of examples chosen for their relevance to fusion applications (only the presentation of the Vlasov equation, in the second section of Chapter 4, might be criticized as so concise as to be almost misleading, since the difference between microscopic and macroscopic fields is not even mentioned). Considerably more space is devoted to the magnetohydrodynamic (MHD) description of equilibrium and stability. This part includes the solution of the Grad-Shafranov equation for circular tokamaks, a brief discussion of Pfirsch-Schlüter, neoclassical and anomalous diffusion, and two relatively long chapters on the most important ideal and resistive MHD instabilities of toroidal plasmas; drift and ion temperature gradient driven instabilities are also briefly presented. The general part concludes with a few chapters on waves, again covering a broad spectrum of topics in a very condensed form: cold plasma waves, Landau and cyclotron absorption, quasi-linear theory, power flow and ray tracing in non-uniform plasmas, the main radiofrequency heating scenarios (ion cyclotron, lower hybrid and electron cyclotron) and the most common velocity space instabilities.The second part describes tokamaks, reversed field pinches, stellarators and open ended systems, and ends with a short chapter on inertial fusion. Although more descriptive in nature, this part offers a succinct introduction to relatively advanced topics, particularly for the tokamak: MHD stability and density limits, non-inductive current drive, bootstrap current, improved confinement regimes and scaling laws of the confinement. Reference to the first, general part, allows an introduction to and explanation of many of the formulas in current use for the interpretation of experimental results. A nice feature of this part is also the concise but very readable introduction to the history of fusion research.The level of the presentation corresponds well to what one would expect in a course for postgraduate students: most topics are discussed rather briefly, but always quantitatively, the mathematics being mostly worked out in full. As should be clear from the description of the content, there is a strong bias towards concrete applications, at the expense of general principles: this goes so far that the derivation of the energy principle for ideal MHD instabilities and of the dielectric tensor of the hot plasma are relegated to appendices, in spite of the fact that the mathematics involved is by no means more complex than that of the applications discussed in the main text. The equations of magnetohydrodynamics are derived in Chapter 5 not as a particular closure of the hierarchy of moments of the Vlasov equation, but using a phenomenological approach. The space devoted to comments and explanations is kept to a minimum, and discussions of the limits of validity of the theoretical models used (Vlasov equation, MHD, cold plasma, etc.) are almost absent: this price had to be paid to condense so many topics in less than 400 pages. The text is nevertheless always clear and easy to follow. The new book will therefore be appreciated both by students entering fusion research and by many senior physicists, for example experimentalists with an interest in the theoretical aspects of their work, wishing to gain a rapid but not too superficial overview of the whole field. It can also be useful for teachers of plasma physics as a source of relevant examples on particular topics worked out in detail. For all the plasma physicists who do not already possess the previous volume by Prof. Miyamoto, it is a useful addition to their library.