One step closer toward nuclear fusion
Nuclear fusion entails fusing atoms together to generate energy—a process similar to that in the Sun—as opposed to nuclear fission, where atoms are split, which entails worries over safety and long-term waste.
After spending a billion euros ($1.1 billion) and nine years' construction work, physicists working on a German project called the "stellarator" said they had briefly generated a super-heated helium plasma inside a vessel—a key point in the experimental process.
"We're very satisfied. Everything went according to plan," said Hans-Stephan Bosch at the Max Planck Institute for Plasma Physics in Greifswald.
The idea is to heat atoms to temperatures of more than 100 million degrees Celsius (180 million degrees Fahrenheit) so that their nuclei fuse.
The fusion would take place in a special vacuum chamber where the atoms, in a hot ionised gas called a plasma, are held floating in place by superconducting magnets so that they do not touch the vessel's cold sides.
The German experiment, using a machine called Wendelstein 7-X, was aimed at seeing whether it was possible to heat helium atoms with a microwave laser and to briefly contain the plasma within the vessel.
The first plasma in the 16-metre-wide (52-foot-wide) machine, from one milligram of helium gas heated by a 1.8-megawatt laser pulse, lasted one-tenth of a second and reached a temperature of around one million Celsius, the institute said. ■