Electron Cyclotron Resonance Ion Sources and ECR Plasmas

Let me say from the start that opening this book on electron cyclotron resonance ion sources (ECRIS) and ECR plasmas is a real pleasure. The book is written by a well known recognized expert in the field, an inquisitive experimentalist with a solid theoretical background. During the many years that Geller has worked in the field, he has clearly accumulated a lot of experience, so that his expert eye allows him to give us a superb overall survey. The book always gives an attractive historical perspective, which shows how the subject developed and gives the opportunity for novices to profit from former trials and errors, the `things' that take time in a growing field. The book aways gives the final word to experiment. The content of the first half of this book covers several aspects of fundamental basic plasma physics, such as wave - plasma interaction (particularly in the EC range), ionization phenomena, confinement of plasma and diffusion in a magnetic field, wave launchers and coupling structures. It is a clever and knowledgeable introduction to the aim of the book, namely the second part, which describes the different ECRIS sources and sheds light on their historical development and on the plasma characteristics of such sources. Thinking about the multidisciplinary interest this book should raise, let us take overdense discharges as an example. The production of discharges at densities above the O-mode cut-off of electron cyclotron waves is an important practical result of ECRIS research, although our understanding of the mechanisms at work has not been fully clear for a long time. Detailed hints are given in this book, suggesting the successive conversion of O- to X- and then to electron Bernstein waves, citing overdense heating ray-tracing calculations of a toroidal magnetic fusion plasma, proposed more than two decades ago. But clear experimental proof of the existence of overdense heating in a toroidal plasma following the above-predicted wave conversion mechanism appeared only last year. This example of cross-disciplinary fertilization indicates the strong interest this book should raise among the different research fields sharing the use of EC waves. This book is up-to-date, the author is well aware of the field and the presentation is clear and attractive. The numerous figures illustrating the text are well designed and meet the high level of pedagogical and communication aims of the book. The obvious purpose of reading this book is to learn about ECRIS and it will be highly appreciated by specialists and newcomers alike, but the book will also be of interest in other fields of plasma physics, for example in magnetic fusion. Overdense heating, which may be on the verge of becoming an experimental tool in toroidal magnetic confinement and which has been the basis of the functioning of ECRIS for many years, stands as a good example. This stimulating book can also be taken as a source of imagination for new experiments and in related fields. Due to its width and breadth, it should interest people in plasma physics, plasma - wave interactions, industrial and applied plasma physics, as well as electron cyclotron resonance heating in nuclear magnetic confinement machines, etc .