German scientists testing experimental fusion device

3 Feb 2016

Greifswald device image via Max Planck Institute

Researchers at the much-acclaimed Max Plank Institute in Germany are hoping to contribute to efforts to build a working fusion reactor with something they are calling the Greifswald device.

While even the mere mention of harnessing affordable, consistent nuclear fusion energy is still seen as a pipe dream reserved for science fiction, this team of scientists believe its experimental fusion device will, at least, contribute to developments in the coming decades.

Named after the area in which the institute is based, the Greifswald device aims to provide an alternative to the much-more-common tokamak research model that uses electromagnetism to confine plasma – necessary for the production of nuclear fusion energy – within a donut-like torus shape.

According to, the institute team’s model will look at the one developed by American physicist Lyman Spitzer back in 1950 called the stellerator, which creates the same results as a tokamak generator, but uses a system of magnetic coils instead.

In August 2015, the latest poster child of the nuclear fusion development world was seen to be a tokamak reactor design called ARC, which has itself begun appearing once again in the news.

The believed benefits of the device – alternatively known as the Wendelstein 7-X (W7-X) stellerator – should allow for the plasma to be kept in place much longer than a tokamak due to its greater stability.

Hard to make, easy to run

However, the head of the project, Thomas Klinger, says that its particularly complex building process might dissuade people from using it as a future nuclear fusion reactor, but added that it would be much simpler to operate once it had begun operations.

Also, it should be noted, the Greifswald device won’t be a generator of energy itself but will be a test bed for the extremes of any future prototype reactors at temperatures of around 1m degrees Celsius.

In response to the researchers’ developments, a physicist not involved with the study, Prof David Anderson of the University of Wisconsin, said: “The impressive results obtained in the start-up of the machine were remarkable.

“This is usually a difficult and arduous process. The speed with which W7-X became operational is a testament to the care and quality of the fabrication of the device and makes a very positive statement about the stellarator concept itself. W7-X is a truly remarkable achievement and the worldwide fusion community looks forward to many exciting results.”

Colm Gorey was a senior journalist with Silicon Republic