Has nuclear fusion energy just become reality?

German Chancellor Angela Merkel visit the site of the new Wendelstein 7-X nuclear fusion experiment. Photo / Getty

Scientists have taken the world a step closer to creating clean, safe energy through nuclear fusion -- a possibility described by a Kiwi physicist as the holy grail of future energy production.

Scientists from the Max Planck Institute for Plasma Physics in Greifswald, Germany, have demonstrated that it is possible to superheat hydrogen atoms to form a plasma of 80 million degrees Celsius using a machine called the Wendelstein 7-X stellarator.

The plasma forms the basis for nuclear fusion, in which hydrogen atoms collide and their nuclei fuse to form helium atoms -- a process which lets off energy and is similar to what happens in our sun.

For decades, researchers have been attempting to develop a power plant favourable to the climate and environment that derives energy from the fusion of atomic nuclei, just as the sun and the stars do.

But research has been hampered by some extremely challenging obstacles -- particularly the practical hurdles of creating and maintaining fusion fire to create the fuel -- and critics have frequently dismissed efforts as a waste of money.

As fusion fire is typically thought to ignite at temperatures of more than 100 million degrees, the fuel -- a thin hydrogen plasma -- must not come into contact with the cold walls of the vessel it's created in.

On Wednesday, nine years of research by the German researchers culminated in a successful experiment using the Wendelstein 7-X stellarator.

After turning the machine on, it produced plasma that lasted just a fraction of a second before cooling down again.

Distinguished Professor Peter Schwerdtfeger, the director of Massey University's Centre for Theoretical Chemistry and Physics, hailed the experiment a "significant advancement" in the field of physics and a step forward into a more sustainable future for energy production.

"This is exciting because it could imply that in the coming decades we could be able to produce large amounts of energy in a safer way, pretty much anywhere on Earth and with little to no harmful products such as CO2," he said.

"Some people describe nuclear fusion as the holy grail of future energy production."

Professor Schwerdtfeger said there were at least 10 to 20 years of research ahead to make nuclear fusion power the main source for energy production, and many obstacles have to be overcome, but it will be important for New Zealand if population growth and energy consumption exceeds the nation's capabilities.

His own research group is collaborating with the Osaka Laser Group in Japan to design new high-energy lasers important in fusion reactions.

Confined by magnetic fields, the plasma created by fusion fire floats virtually free from contact within the interior of the vacuum chamber it is created in. So far two different designs have prevailed -- the stellarator and another called the Tokamak -- and both are being investigated at the global Institute for Particle Physics.

At present, only a Tokamak is thought to be capable of producing energy-supplying plasma and this is the international test reactor ITER, which is being constructed in Cadarache, France.

The Wendelstein 7-X, the world's largest stellarator-type fusion device, will not produce energy but should demonstrate that stellarators are also suitable as a power plant.

The machine is expected to soon put the quality of the plasma confinement on a par with that of a Tokamak for the first time.

And with discharges lasting 30 minutes, the stellarator should demonstrate its fundamental advantage -- the ability to operate continuously.

In contrast, Tokamaks can only operate in pulses without auxiliary equipment.