GREIFSWALD, Germany — Scientists in Germany have switched on an experiment they hope will advance the quest for nuclear fusion, considered a clean and safe form of nuclear power.

German Chancellor Angela Merkel, a physicist herself, pushed the button Wednesday to inject a tiny amount of hydrogen into the Wendelstein 7-X device at the Max Planck Institute for Plasma Physics in Greifswald.

A massive microwave array then heated up the hydrogen, turning it into a super-hot gas known as plasma similar to that found in the sun.

The Greifswald device won’t generate energy but instead test a technology that may be used to hold plasma in place in future reactors.