Physicists in Germany have used an experimental nuclear fusion device to produce hydrogen plasma in a process similar to what happens on the Sun. The test marks an important milestone on the road towards this super-futuristic source of cheap and clean nuclear energy.

Earlier today in an event attended by German Chancellor Angela Merkel (herself a PhD physicist), researchers from the Max Planck Institute in Greifswald turned on the Wendelstein 7-X stellarator, an experimental nuclear fusion reactor. (Actually, the researchers let Merkel do the honors.) This €400 million ($435 million) stellarator is being used by physicists to test the technical viability of a future fusion reactor.

“With a temperature of 80 million degrees and a lifetime of a quarter of a second, the device’s first hydrogen plasma has completely lived up to our expectations,” Hans-Stephan Bosch, whose division works on the Wendelstein 7-X, said the press release.