鈥淚T HAS long been the ambition of scientists to emulate the sun.鈥� This is how, half a century ago, John Cockcroft, one of the great nuclear pioneers, began an article in this magazine on the prospects for generating useful energy from nuclear fusion. Today sceptics joke that fusion is the energy source of the future 鈥� and always will be. Commercial fusion, they gleefully point out, is as far away now as it was 50 years ago.
That鈥檚 true up to a point, but unfair. Even in the optimistic days of 1958, the founder of the UK鈥檚 Atomic Energy Research Establishment was well aware of the challenges. 鈥淲e will have many problems to face鈥� even if all goes well and we meet no road blocks we would still have the further engineering problem of designing and constructing a prototype of a practical and economic thermonuclear power station,鈥� Cockcroft wrote (New 杏吧原创, 30 January 1958, p 14).
Now an international consortium known as ITER (鈥渢he way鈥�, in Latin), is ready to start building that prototype in Cadarache, France (see 鈥淲ork starts on the world鈥檚 biggest fusion reactor鈥�). Critics will carp that there are still important questions to be asked. Why bother to build a fusion reactor when there is a perfectly good one 8 light-minutes away? Why not spend the $10 billion 鈥� likely to be an underestimate 鈥� on wind or solar power instead?
Advertisement
They are easily answered. We need as many clean energy options as we can get, and commercial fusion power is within sight. In Cockcroft鈥檚 day there were serious gaps in our knowledge of the relevant science. He himself referred to being on 鈥渁 longish road, and we cannot see the end of the road鈥�. Today we can.
鈥淲e need as many clean energy options as we can get, and fusion power is within sight鈥�
Thanks to studies carried out over the intervening decades, the science that ITER has to rely on is well established. The challenges lie in the technology, such as developing wall materials to withstand the pummelling by subatomic particles and cutting the cost of the superconducting magnets that will confine plasma that is 10 times the temperature of the sun鈥檚 core. The more that we spend now, the sooner we鈥檒l reach our goal.
The last surge in spending on fusion came during the 1970s, when oil-producing countries in the Middle East cut supplies to the west. As delegates prepare for December鈥檚 climate change conference in Copenhagen, the case for boosting funding is stronger than ever. Whatever the outcome, the risk of dangerous climate change is a real one, prompting thoughts of draconian measures to tackle it. Compared with the more exotic schemes for large-scale manipulation of the environment now coming under serious consideration 鈥� which do look 50 years away 鈥� fusion power is a racing certainty. It鈥檚 safer too. A technology that messes with our planet鈥檚 climate is what got us into trouble in the first place.