An Indispensable Truth: How Fusion Power Can Save the Planet
Francis F. Chen, Springer, 2011, 433 pages, ISBN 978-1-4419-7819-6, $50 hardcover
This book was written to convince us that large controlled fusion based electrical power plants are not only possible but are indispensable. Part I reviews the evidence for global warming, the use and lifetime of fossil fuels as our primary source of power, what Chen calls “backbone power,” a variety of renewable power sources, and nuclear fission reactors. It continues with technical descriptions of some of the newer devices, such as very tall windmills and quantum dot solar cells. Chen concludes that none of these power sources are feasible as a long term source of backbone power and that we must develop and use controlled fusion.
Part II is about fusion power starting with the fundamental physics of nuclear fusion and going on to describe how a hot, dense deuterium-tritium plasma might be coerced or coaxed into becoming a contained, stable source of fusion energy. Chen concludes with a discussion of what a practical controlled fusion based power plant might look like. Throughout, the author strives to present all this material in a non-mathematical format and at a level that a well-educated non-scientist can understand. To this end the book contains many drawings and figures to explain the complex interactions between plasmas and magnetic fields that exist inside fusion devices like stellarators and tokamaks. I suspect that those readers who have no familiarity with the basic physics of electric and magnetic fields will struggle a bit with this material but in principle it should be accessible to them.
Although the real strength of this book is in the second part, and the author suggests that some readers might wish to skip the 170 pages that comprise Part I, this section contains a wealth of information about climate change and energy sources that will be of interest to many readers. I would only caution that in his zeal to convince us of the need to pursue research on fusion power, Chen sometimes includes sweeping generalizations and negative conclusions about the long term use of any power source except fusion along with some off the cuff remarks that are sometimes inaccurate and distracting. With regard to renewable energy sources Chen focuses too much on the negative aspects of each source and tends to conclude that since they all have limitations none of them is useful as a reliable source of backbone power. He chooses to ignore the possibility of combining these sources into a comprehensive power producing and utilization scheme which would include sources of more reliable power such as natural gas or nuclear fission along with increased energy conservation. However, in some cases Chen’s own careful and objective descriptions of power sources such as solar cells provide good arguments to contradict his own negative conclusions.
Part II, Chapters 4-11, deals primarily with the physics of magnetically contained, hot, dense plasmas, and here the book offers an excellent opportunity for the non-expert to understand what has been achieved so far and what is still left to be done if controlled nuclear fusion is to become an important source of energy in the future. Chapters 4 and 5 cover the basic nuclear and plasma physics of controlled fusion. The nuclear physics of fission and fusion processes is described, including what is needed to induce fission and fusion reactions and the amount of energy released from these reactions. Chen describes what a plasma is and how magnetic fields can be used to confine the energetic components of a plasma. The basic concept of a toroidal magnetic bottle is introduced along with an explanation as to why a simple toroidal coil will not produce a magnetic field configuration that can stably contain a plasma. The stellarator configuration is introduced along with a discussion of the temperature, confinement time and density parameters for a plasma that must be achieved to realize controlled fusion. The last part of this chapter introduces the problem of plasma instabilities.
Chapters 6 and 7 focus on the most advanced magnetic confinement configuration, the Tokamak, and describes in great detail with many excellent figures the behavior of a plasma in a Tokamak along with ways to heat a plasma to temperatures sufficient to produce a self sustaining fusion reaction, i.e. ignition. These chapters describe much of what is understood and not understood about plasmas confined in a Tokamak that approaches the conditions required for ignition, particularly the unexpected stabilities and instabilities, not all which are currently understood theoretically.
Chapter 8 reviews the impressive progress that has been achieved towards producing a confined plasma with the parameters required for a sustained, useful, controlled fusion reaction. Yet Chen also points out that there are several important characteristics of plasma behavior such as disruptions that may pose serious problems. The chapter concludes with a description of the International Thermonuclear Experimental Reactor (ITER) tokamak project which was (as of the writing of this book) scheduled to start operation with a deuterium-tritium plasma in 2020. Chen makes it clear that this is definitely an experimental project with no guarantee that it will it demonstrate that a fusion reactor can really be built but he believes that the amount of progress made to date bodes well for the future. Assuming that ITER achieves ignition, Chapter 9 describes the considerable engineering challenges that lie ahead in building an economically useful fusion reactor. Chapter 10 entitled “Fusion Concepts for the Future” briefly describes other possible ways to make a fusion reactor including inertial confinement.
Although Chen is an unabashed advocate for an all out effort to try to develop a fusion reactor, he presents what appears to this non-expert to be a valuable, mostly balanced, and mostly objective assessment of this issue. He states, “There are problems in the technology of fusion so serious that we do not know if they can be solved. But the payoff is so great that we have to try.”
California State University, Los Angeles
These contributions have not been peer-refereed. They represent solely the view(s) of the author(s) and not necessarily the view of APS.