Nuclear Fusion Feat Moves Us One 'Huge Step' Forward

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."

• Iter is slated to begin burning deuterium-tritium fuel in 2035. The idea is that it will generate more heat than is required to maintain that level of heat. But demonstrating such a scenario is possible is key, and that's one reason why Wednesday's announcement is so noteworthy. As the Financial Times explains, "In half a century of experiments around the world scientists have failed to generate more energy from a fusion reaction than the power-intensive system consumes."
• So how much is 59 megajoules of energy? Enough to get about 60 tea kettles to boiling, per the BBC. If that sounds underwhelming, the Guardian talks to a nuclear materials researcher at Imperial College London who puts it like so: "Five seconds doesn’t sound like much, but if you can burn it for five seconds, presumably you could keep it stable and keep it burning for many minutes, hours, or days, which is what you are going to need for a proper fusion power plant. It’s the proof of that concept that they have achieved."
• Here's how the head of the JET lab puts it: "We've demonstrated that we can create a mini star inside of our machine and hold it there for five seconds and get high performance, which really takes us into a new realm."
• If you want to know more about the doughnut-shaped machine, called a tokamak, and how it works, the Financial Times provides a diagram here.

(More discoveries stories.)