In pursuit of fuel's holy grail

I have just sat down to write this review under 180 watts of electric light in a room cooled by a 500-watt air conditioner at a computer consuming 200 watts - nearly a kilowatt in total. If I include transportation, manufacturing and distribution of the food and material goods I consume and so on, then, in round numbers, averaging over day and night, summer and winter, I estimate that my life is supported by about five kilowatts of power. This is about typical for a denizen of the developed world. If I now account for all the other six billion people on earth, most of whom use much less power, this implies a global power demand of about ten billion kilowatts. Over three-quarters of this power comes from the burning of fossil fuel at 100,000 times the natural replacement rate, so that our petrochemical inheritance should be spent within my children's lifetime; coal within a couple of centuries. Last year, I can be credited with enriching the carbon dioxide content of our atmosphere by a couple of tons, doing my part towards warming the atmosphere and hastening us along the path to catastrophic climate change as the developing world demands an equivalent supply of power.

These sobering and ominous facts provide the backdrop to T. Kenneth Fowler's The Fusion Quest. The author has spent a scientific lifetime fighting, initially as a foot soldier and now as a general, in the campaign to achieve environmentally safe energy self-sufficiency for the world by combining two types of hydrogen - deuterium and tritium - in nuclear fusion reactions at temperatures of hundreds of millions of degrees, confined either by enormous magnetic fields or intense bursts of light from giant lasers. This quest is an enticing one. The ideal fusion reactor consumes an effectively inexhaustible fuel and creates a relatively manageable radioactive waste, at least in comparison with the fission nuclear reactors in operation.

However, attaining this dream has proved to be extremely hard. In well over 40 years of triumphs and disappointments, the fusion programme is now at the point where it can chaperon these nuclear reactions so as to produce 10,000-kilowatt pulses of nuclear power - a milestone, but still perhaps 20 years from a network of commercial power-stations. Furthermore, this power is tainted.

Just like the wealth that is accrued by one generation through exploitation and slavery and supports philanthropy in the next, the electricity from fusion cannot quite escape the twin curses of Hiroshima and Chernobyl. It is also burdened with the memory of the overly optimistic, "can do" promises of the past. Not surprising then that governments of the major energy-consuming nations have greeted the achievement of controlled thermonuclear fusion not with rejoicing but with a failure of political nerve, especially in the United States. It is even less remarkable that Fowler's personal memoir of how fusion got to this point should end with a powerful plea to keep the faith.

This is not a popular book. It contains numbers, tables and, in a mathematical appendix of some sophistication, equations. The graduate physicist will read explanations of the Vlasov equation, drift waves, Onsager relations etc with some understanding but not, in most instances, with much familiarity. Those outside the field will have to turn elsewhere and be prepared for some hard work if they really want to appreciate the technical challenges of fusion research. Neither is this an exciting book. In contrast with much contemporary science writing, the prose is business-like and clear and does its best by a conceptually dense field. Tritium is described simply and quite accurately as an isotope of hydrogen containing two neutrons and a proton rather than whimsically as an unstable menage a trois. Furthermore, The Fusion Quest reveals little of the personalities of its cast of characters who appear mostly as names, identified by positions and credited with insights and prizes. Nowhere could we learn that Professor Nukem keeps ferrets and used to play back-up bass for Blood, Sweat and Tears. But it does exhibit, in an unforced and seemingly unselfconscious manner, what it is like to work for a lifetime in big science and how those so engaged have learned, in the second half of this century, to conduct themselves. Whether one is visiting Mars, seeking the Higgs boson or trying to save the world from its profligacy, one must combine a rigorous attention to engineering detail with a weather eye on the political and economic winds that can turn from fair to foul in weeks. I hope The Fusion Quest is read not only for its science but also by those politicians and civil servants who, without the benefit of a technical education, are charged with making some hard and long-reaching decisions on energy policy. If it is, then it cannot fail to raise the level of public discourse, and for that the rest of us will be forever in Fowler's debt.

Roger Blandford is professor of theoretical astrophysics, California Institute of Technology United States.