Germany and China make nuclear fusion breakthroughs

Both countries are working to harness the energy that fuels our Sun

It’s easy to get nuclear fission and fusion mixed up. We can already do nuclear fission, it’s how our nuclear power plants work. Incredible amounts of energy are captured in these plants by splitting the nucleus of an atom. Unfortunately we’ve never been able to harvest energy from nuclear fusion, a process that we know takes place inside our Sun.

Being able to harness the same energy that fuels the Sun could be a game-changer. Unlike nuclear fission, which leaves us with radioactive by-products, fusion is clean. The downside is that it’s very difficult to work with because it requires absurdly high temperatures. I’m not exaggerating; we’re talking hotter than the Sun.

Major breakthroughs

Last week German Chancellor Angela Merkel flipped the switch that activated Germany’s nuclear fusion machine, the Wendelstein 7-X (W7X) stellarator. The test was successful and marks a major milestone on the path to using nuclear fusion for our own energy needs. The stellarator heated hydrogen gas to 80 million degrees Celsius. Think about that. 80 million degrees Celsius. This allowed them to create a cloud of hydrogen plasma that they maintained for a quarter of a second.

Image © Bernd Wuestneck

China surprised the world last week with their own major announcement, claiming that their nuclear fusion machine had also been activated successfully. Their machine, the Experimental Advanced Superconducting Tokamak (EAST), heated hydrogen to around 50 million degrees Celsius. That’s quite a bit cooler than Germany’s recent result, but we’re still talking millions of degrees Celsius. What’s particularly impressive about China’s test is that they claim to have maintained the plasma for 102 seconds.

China's EAST. Image © Chinese Academy of Sciences

Going forward

It blows my mind to think that, in research facilities on Earth, scientists are creating temperatures that are hotter than the sun. Temperature is only one part of the tests, the other being the time that the plasma has been held for. Germany’s plasma was only sustained for a quarter of a second but China held theirs for over a minute. Eventually we will need to collect heat energy and particles from the plasma, so we need it maintained for as long as possible.

The goal for these nuclear fusion reactions is around 100 million degrees Celsius and for as long as possible. Germany is getting close with the temperature and China has demonstrated it’s possible that plasma can be held for a considerable time. Now both countries will be working on the other aspects as China look to raises their temperatures and Germany look to extend the lifespan of their plasma clouds.

These are just the initial experiments to test the machines. They work but it’s not known how successful future experiments will be. Can they end up holding hydrogen plasma for half an hour? Can we for the first time collect clean energy from reactions that mimic our Sun? It’s hard to say and it’s likely we’ll see baby steps for many years. We’re not going to be running our homes with fusion reactors any time soon. However, I’m glad that we have two nations making progress at the same time. I’m hoping their efforts will mimic the space race, where both countries competitively drive and motivate each other to succeed.