The world’s largest stellarator Wendelstein 7-X reached 20 million degrees Celsius back in 2018. But analysis shows it should handle much more. The next round of experiments starts next year.
Image by Pete Linforth from Pixabay
@kralizec and subscribe to my Youtube channel at Kralizec Gaming Youtube ChannelThe popular German stellarator Wendelstein 7-X is quite successful and gathers experience as an incredible hi-tech fusion technology that is an alternative to “ancient” tokamaks. Since first achieving plasma in 2015 it is marching forward. The stellarator’s team recently confirmed that thanks to new advances they will reach temperatures that will surpass the Sun’s core temperature – 15.7 million degrees Celsius by at least two times.
Stellarators are fusion reactions that rely purely on the magnetic fields of external coils to keep plasma stable. This causes them to have unusual, almost bizarre shapes. Designing them is so complex it has to be done by supercomputers. Wendelstein 7-X is the largest functional stellarator in the world. It uses an array of superconductive magnetic coils that produce magnetic fields that keep its plasma safe.
In 2018, Wendelstein 7-X reached a record plasma temperature of 20,000,000° Celsius – more than the temperature is at the core of the Sun. Since then, it has gone through upgrades that will allow us to surpass this temperature considerably. The key was to overcome specific temperature losses called neoclassical transport. These losses take place when heated up particles collide and get pushed out of the magnetic cage. These types of heat losses happen much more often to stellarators than traditional tokamaks.
Thus, the Wendelstein 7-X’s team thoroughly tinkered with the magnetic fields until they got everything into perfect balance. Novimir Pablant from the Princeton Plasma Physics Laboratory (PPPL) and his colleagues recently analyzed the record experiments from 2018 and found the “min-maxed” stellarator truly has reduced heat losses including neoclassical transport.
The analysis also confirmed that Wendelstein 7-X should definitely hold the plasma that will be heated up to double the Sun’s core temperature. The stellarator will get its chance next year when new experiments await it. This time they will have a completely new water-cooled system allowing them to perform longer experiments.
