A new experimental fusion reactor built by the Max Planck Institute of Plasma Physics in Germany received a brief test run on February 3, bringing the promise of clean and sustainable fusion-generated power one step closer to reality.

This new reactor, called the Wendelstein 7-X, is a doughnut-shaped, 425-ton device, made up of a series of winding magnetic segments. The reactor was test-fired using helium last December, since helium is easier to convert to plasma than hydrogen (the intended fuel for a fusion reaction), and helium plasma can clean the interior of the plasma chamber of any dust left over from the unit’s construction.

This test firing of the reactor was initiated during an inaugural ceremony for the device, with German Chancellor Angela Merkel activating the device itself. The Wendelstein 7-X, using a 2 megawatt microwave pulse, heated a sample of hydrogen gas to 80 million degrees, converting it into a plasma for a quarter of a second, briefly simulating the conditions found within the Sun.

The Wendelstein 7-X isn’t meant to be a fusion reactor that will generate power at economical levels, but rather is a proof-of-concept device, intended to generate fusion reactions via hydrogen plasma for up to 30 minutes at a time, testing the potential rigors that future fusion power plants would have to be able to endure to maintain continuous operation.

This test run of the reactor didn’t generate a fusion reaction, but was intended to test the unit’s ability to generate hydrogen plasma. Dr. Hans-Stephan Bosch, head of the project’s operations division, says that they will ramp up to generating actual fusion reactions over time: “In a later phase of W-X, starting in 2019, we will use deuterium and we will get fusion reactions, but not enough to get more energy out than we are putting in.”