Daily Mail By Stephen Adams and Allan Hall In Berlin Dec. 12, 2015
- The Wendelstein 7-X machine in Germany cost €1billion to construct
- The device recreates conditions similar to those occurring inside stars
- Technology could lead to limitless supplies of clean and cheap energy
- It created one-million-degrees-centigrade plasma for tenth of a second
Its twisted construction resembles the pretzels of its native Germany. But this €1billion machine could help solve the planet’s energy problems – and make harmful fossil fuels redundant.
Scientists celebrated last week after they used the device to make a big leap towards a limitless supply of clean energy created from nothing but water.
The eventual goal is to build a reactor that uses nuclear fusion to create vast amounts of power.
And one British scientist said last night that nuclear fusion as a source of clean energy was ‘close enough to be able to taste it’.
Fusion – which happens in our nearest star, the sun – occurs when two atomic nuclei fuse, releasing enormous amounts of energy.
Unlike the fission process in today’s nuclear reactors, it creates little if any dangerous waste material. But for fusion to occur, hydrogen gas has to be super-heated to form a ‘plasma’ at 100 million degrees Centigrade.
The plasma is generated and tightly contained in a sealed container – and if the plasma touches the sides, they will melt.
Until now, most fusion containers have been a symmetrical doughnut design, called a tokamak, which ‘cages’ the plasma by using supercooled magnets and a powerful current flowing around the loop.
But now scientists have switched on a radical new machine, dubbed Wendelstein 7-X, which uses specially shaped magnets to do away with the need for the current.
The device is a type of ‘stellarator’ – meaning it recreates conditions similar to those inside stars.
On Thursday, they took a major step forward, heating one milligram of helium gas inside the 50ft-wide twisted pretzel, to create a one-million-degrees-centigrade plasma which lasted a tenth of a second.
Dr Hans-Stephan Bosch of the Max Planck Institute of Plasma Physics in Greifswald, in North-East Germany, where the device is located, said: ‘We are very satisfied – everything went according to plan.’
Professor Steven Cowley, head of the UK’s Centre for Fusion Energy at Culham, near Oxford, said the magnets had been shaped by supercomputer to keep the plasma from touching the sides while it travelled at 700 miles a second.
The UK’s own machine, JET, has already created a 250 million degrees plasma from hydrogen and produced 16 megawatts of power – proving nuclear fusion on an industrial scale is possible.
But – like other fusion machines – JET consumes huge amounts of energy, in part because a five million amp current is needed to help control the plasma.
Prof Cowley said: ‘You want a fusion reactor to be on all the time, so you’d like not to have to push a large current around 24/7.
‘Wendelstein is a natural design which does without the current. It gets the magnetic field controlling the plasma to twist, using weird-shaped magnets. It’s a different route to nuclear fusion.’
And he added that nuclear fusion as a source of unlimited energy might be only decades away.
‘We have got close enough to be able to taste it,’ he said.
The next step for the stellarator is to create and control a hydrogen plasma at much higher temperatures. A much bigger €15 billion machine called the International Thermonuclear Experimental Reactor (ITER) is now being built near Aix-en-Provence in France.
Scientists hope it will be the first to produce a self-sustaining fusion reaction, called a fusion burn. This is when energy is only needed to fire it up, rather than keep it going.
Prof Cowley said: ‘If it does burn – and all the predictions are that it will – it will be a Wright Brothers moment.’