Nuclear fusion: JET scientists report record energy production

 Scientists of the Joint European Torus (JET), Europe's largest fusion reactor, claim to have produced more than twice the energy than the last record measurement in 1997 in a new experiment (Le Monde):

Scientists working at a European experimental facility in the UK claimed Wednesday (February 9th) that they have produced more energy from nuclear fusion than ever before. An alternative to the nuclear fission used in current power plants, nuclear fusion aims to reproduce what happens in the heart of the Sun and is considered by its supporters to be the energy of tomorrow, in particular because it produces little waste. – and much less radioactive than those from a conventional reactor – and no greenhouse gases.

A team from the Joint European Torus (JET), the world's largest fusion reactor, located near Oxford, has succeeded in generating 59 megajoules of energy from this process, more than doubling the previous record set in 1997, according to the UK Atomic Energy Authority (UKAEA). The results "are the clearest demonstration on a global scale of the potential of fusion to provide sustainable energy," the same source said in a statement.

JET's tokamak fusion reactor, a huge donut-shaped magnetic chamber, is the most efficient in the world and maintains a tiny mixture of deuterium and tritium at its core. These light atoms, isotopes of hydrogen (they have one and two additional neutrons respectively), are heated to temperatures ten times higher than at the center of the Sun in order to fuse them into heavier helium atoms. This reaction releases a large amount of energy: for an equal amount, nuclear fusion can produce four million times more energy than coal, oil or gas.

The results announced Wednesday show the possibility of sustaining fusion energy production for five seconds, not long enough for the process to be viable. But, “if we can maintain the fusion for five seconds, we can do it for five minutes, and then for five hours” with future more efficient machines, estimates Tony Donne, of the EUROfusion consortium.

The data gathered by Oxford scientists could prove valuable for the ITER fusion reactor, even more advanced than JET and under construction in the south of France. Bernard Bigot, the director general of the international ITER project, welcomed these results, believing that they were now approaching "industrial scale" of production. The French project thus involves both China and the European Union, India, Japan, South Korea, Russia and the United States.

ITER is nevertheless criticized, especially among ecologists, who see it as a “scientific mirage” and “a financial abyss”.