A star on earth

Tuesday 29 August 2017
In southern France, 35 nations are collaborating to build the world's largest tokamak, a magnetic fusion device that has been designed to prove the feasibility of fusion as a large-scale and carbon-free source of energy based on the same principle that po

Where there is a will, as was the case of putting a man on the moon, there is a way.

ANU physicists are helping lead a global effort to make a star on Earth, otherwise known as a nuclear fusion facility that could produce inexhaustible clean power. Will Wright reports.

Energy pundits see nuclear fusion as the Holy Grail. Nuclear fusion occurs in nature – powering the Sun and all the stars in the Universe – and is considered to be the ultimate source of all renewable power.

Where there is a will, as was the case of putting a man on the moon, there is a way.

If reproduced and harnessed on Earth, nuclear fusion has the potential to provide sustainable, safe, zero-emission, baseload power to electricity grids, without the long-lived radioactive by-products of fission power or the potential to be weaponised.

Many nations believe nuclear fusion has the potential to be a major power source for future generations. Some countries are jointly funding the construction of the ITER (International Thermonuclear Experimental Reactor) in France that will come online in the late 2020s. It is designed to prove the scientific and technical feasibility of nuclear fusion and will produce 500 megawatts of thermal power.

Australia also has skin in the game, becoming the first non-member state to enter a formal collaborative agreement with ITER in September 2016. As part of the Australian effort, physicists at ANU are developing theory and interpretive models for current and next-generation fusion experiments. They are also conducting fusion materials research and plasma diagnostic development to better understand how containment materials behave in the extreme environment of a fusion reactor, and characterise the plasma edge.

So what will ITER look like and how will it work?

Associate Professor Matthew Hole from the ANU Research School of Physics and Engineering says ITER will cover 42 hectares and house a gigantic donut-shaped magnetic vessel called a tokamak which can confine the energy processes that power a star.

“Once it’s built, scientists will pump hydrogen isotopes into the tokamak and then inject it with extreme power such as radio waves, microwaves and particle beams, so that the hydrogen starts to fuse at the extreme temperatures required to produce helium – in the order of 150 million degrees Celsius,” Hole says.

“In the process, neutrons will be released that carry huge amounts of energy. A neutron is a neutral subatomic particle, so it can escape from the magnetic field and its kinetic energy can be converted into electricity by heating the thermal blanket and driving a generator.”

Sounds simple, right?

Hole says tokamak plasma is actually a "fiendishly hard beast to tame" and likens the fusion energy challenge to putting a man on the moon in 1969.

“The temperatures inside the tokamak are 10 times hotter than the centre of the Sun – keeping the plasma ignited and most of the energetic-charged exhaust particles confined is perhaps the ultimate complex physical systems challenge.”  

Hole is the only ITER Science Fellow outside member nations the European Union, Japan, US, Russia, South Korea, China and India.

He leads an ANU research group in plasma theory and modelling and is also Chair of the Australian ITER Forum, a network of more than 180 scientists and engineers in Australia that advocate for fusion power development and ongoing Australian engagement in ITER.   

Making fusion power a commercial reality entails many research and technological challenges, Hole says.

“Even if a fraction of energetic-charged exhaust particles escape, they can cause serious damage to the walls,” he says.

It would be optimistic to expect nuclear fusion to make a sizable contribution to electricity grids globally before the end of this century, but Hole believes the feat could be achieved with strong political will.

“With an increase in funding internationally by a factor of 10 – from about $US30 billion to about $US300 billion – we could see fusion power feeding into the grid within 15 years,” he says.

“Where there is a will, as was the case of putting a man on the moon, there is a way. After all, ITER is Latin for ‘the way’.”

This story, written by Will Wright, originally appeared in ANUreporter.

Updated:  24 September 2017/Responsible Officer:  Director, Energy Change Institute/Page Contact:  Webmaster