German scientists have generated the first plasma in the Wendelstein 7-X stellarator using hydrogen in the hope of bringing nuclear fusion closer to reality.
The experiment was launched after nine years of construction and testing. The researchers said their biggest concern was to ensure cooling of the complex magnets that keep the plasma inside the device floating.
"Everything went well today," said Robert Wolf, a senior scientist involved with the project. "With a system as complex as this you have to make sure everything works perfectly and there's always a risk."
The €400m (£302m) device located at the Max Planck Institute for Plasma Physics in Greifswald uses a different design to the more common tokamak, such as the one currently being built by the ITER project in France.
The stellarator nuclear fusion reactor was invented in 1950 by American physicist Lyman Spitzer. It has the same doughnut shape as a tokamak but uses a complicated system of magnetic coils instead of a current. As a result, the Wendelstein device should be able to keep plasma in place for much longer than a tokamak.
"The stellarator is much calmer," said Thomas Klinger, who heads the project. "It's far harder to build, but easier to operate."
Part of a global effort to harness nuclear fusion to generate clean energy, the Wendelstein facility will test the extreme conditions such devices will be subjected to if they are ever to generate power.
The device was first fired up in December using helium, which is easier to heat and has the advantage of ‘cleaning’ any minute dirt particles left behind during the construction of the device.
While critics have said the pursuit of nuclear fusion is an expensive waste of money that could be better spent on other projects, Germany has forged ahead in funding the Greifswald project.
Chancellor Angela Merkel, who holds a doctorate in physics, personally pressed the button at Wednesday's launch.
"As an industrial nation we want to show that an affordable, safe, reliable and sustainable power supply is possible, without any loss of economic competitiveness," she said. "The advantages of fusion energy are obvious."
Advocates acknowledge that the technology is probably many decades away, but argue that - once achieved - it could replace fossil fuels and conventional nuclear fission reactors.