We are now "a huge step closer to conquering one of the biggest scientific and engineering challenges of them all," according to the CEO of the UK Atomic Energy Authority: developing "practical" nuclear fusion, as the BBC puts it. Nuclear fusion is the energy process that powers the stars, and the same facility that set a record in 1997 for the amount of energy released in a sustained fusion reaction have outdone themselves. Researchers at Britain's Joint European Torus (JET) announced Wednesday that they managed to generate 59 megajoules of heat inside a doughnut-shaped machine and sustain it for five seconds. The 1997 record was 21.7 megajoules.
- CNN offers a primer on nuclear fusion, which is the fusing of at least two atoms into a bigger one. The process of doing so releases a whole lot of energy—zero-carbon energy—as heat. The nuclear power we use today is generated in a process known as fission: It splits the atoms, rather than fuses them, and it spits out radioactive waste. The fusing requires heat, and lots of it. The temperatures in the machine are 10 times hotter than the center of the sun; the gravitational pressure on Earth is lower, which is why the temps need to be so much higher.
- As for what was fused in this case, the Guardian reports JET has been looking at whether a sustained fusion reaction would be possible using a superheated gas of two hydrogen isotopes—deuterium (which is easy to source from sea water) and tritium (which needs to be produced)—that combine under heat and pressure to form helium gas. "The latest results suggest that it is and provide crucial confirmation for Iter, a larger fusion project being built in the south of France."