The lasers fuelling hopes of unlimited, clean nuclear energy

A major engineering milestone in the quest for nuclear fusion holds the promise of a future without energy fears

Science Editor

A milestone has been reached in the 60-year struggle to harness the nuclear reactions that power the Sun in an experiment that could lead to a way of producing an unlimited source of clean and sustainable energy in the form of nuclear fusion.

Scientists in California said on Wednesday night that they have for the first time managed to release more energy from their nuclear fusion experiment than they put into it, which marks a critical threshold in eventually achieving the goal of a self-sustaining nuclear-fusion reaction.

Nuclear fusion uses a fuel source derived from water and produces none of the more dangerous and long-lasting isotopes, such as enriched uranium and plutonium, that result from conventional nuclear power plants, which rely on the fission or splitting of atoms rather than their fusion.

Researchers involved in the Nuclear Ignition Facility (NIF) at the Lawrence Livermore National Laboratory said that they have used 192 laser beams to compress a tiny fuel pellet less than half the diameter of a human hair in such a way that it triggered the net release of energy by nuclear fusion.

The fuel, composed of the two hydrogen isotopes tritium and deuterium derived from water, was compressed together under enormous pressures and temperatures for less than a billionth of a second, but this was enough to see more energy coming out of the experiment than went into it.

“We are fusing deuterium and tritium, which are isotopes of water, in a way that gets them to run together at high enough speed to overcome their natural electrical repulsion to each other,” said Omar Hurricane of the Livermore laboratory. 

“We are finally, by harnessing these reactions, getting more energy out of these reactions than we are putting into the deuterium-tritium fuel... We took a step back from what we tried before and in the process took a leap forward,” said Dr Hurricane, who led the NIF study published in the journal Nature.

There are currently two parallel approaches to nuclear fusion. One uses laser energy to compress fuel pellets -- like the NIF experiment -- and aims to keep the fuel in place by a process known as inertial confinement.

The JET experiment uses a 'tokamak' (pictured) that confines plasma using a magnetic field in the shape of a torus. Image credit: JET

The other approach is to build a complex magnetic “bottle” to hold the hot, electrically charged plasma of the fuel in place. This magnetic confinement is the strategy of the Joint European Torus (JET) experiment in Culham, Oxfordshire, and the international ITER nuclear fusion plant under construction at Cadarache in southern France.

Both approaches aim to gain more energy than is put into the system, and ultimately to a critical stage called “ignition” when the reaction becomes self-sustaining, which would mean that fusion could be exploited practically in power plants as an unlimited source of clean energy.

The breakthrough at NIF was made possible by altering the laser pulses focusing on the fuel pellet in such a way that it led to the even compression of the capsule holding the deuterium and tritium, said Debbie Callahan, one of the researchers involved.

“We had to compress the capsule by 35 times. This is like saying that if you started with a basketball it would be like compressing it down to the size of a pea, but keeping the perfect spherical shape, which is very challenging,” Dr Callahan said.

Professor Steve Cowley, director of the Culham Centre for Fusion Energy, said that the two approaches to nuclear fusion are beginning to make significant headway after decades of painstakingly slow research. 

“We have waited 60 years to get close to controlled fusion, and we are now close in both magnetic and inertial-confinement research. We must keep at it,” Professor Cowley said.

“The engineering milestone is when the whole plant produces more energy than it consumes – ITER, the successor to JET, will be the first experiment to do this. ITER is going slowly but progress is happening,” he said.

Start your day with The Independent, sign up for daily news emails
Arts and Entertainment
The Doctor and Clara have their first real heart to heart since he regenerated in 'Deep Breath'
TV
Life and Style
Apple showed no sign of losing its talent for product launches with the new, slightly larger iPhone 6 making headlines
techSecurity breaches and overhyped start-ups dominated a year in which very little changed (save the size of your phone)
Arts and Entertainment
Jamie Oliver
filmTV chef Jamie Oliver turned down role in The Hobbit
News
The official police photograph of Dustin Diamond taken after he was arrested in Wisconsin
peopleDownfall of the TV star charged with bar stabbing
PROMOTED VIDEO
Arts and Entertainment
Jeremy Clarkson, left, and Richard Hammond upset the locals in South America
tvReview: Top Gear team flee Patagonia as Christmas special reaches its climax in the style of Butch and Sundance
News
people
Sport
Ashley Barnes of Burnley scores their second goal
footballMan City vs Burnley match report
Arts and Entertainment
Peter Mayhew as Chewbacca alongside Harrison Ford's Han Solo in 'Star Wars'
film
News
i100
Arts and Entertainment
Man of action: Christian Bale stars in Exodus: Gods and Kings
film
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
Arts and Entertainment
Tracy Emin's 1998 piece 'My Bed' on display at Christie's
artOne expert claims she did not
News
Ernesto Che Guevara and Fidel Castro, right, met at Havana Golf Club in 1962 to mock the game
newsFidel Castro ridiculed the game – but now investment in leisure resort projects is welcome
News
Hackers revealed Oscar-winning actress Lawrence was paid less than her male co-stars in American Hustle
people
Arts and Entertainment
Clueless? Locked-door mysteries are the ultimate manifestation of the cerebral detective story
booksAs a new collection of the genre’s best is published, its editor explains the rules of engagement
Sport
Robin van Persie is blocked by Hugo Lloris
footballTottenham vs Manchester United match report
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Business Manager

£32000 - £40000 per annum: Recruitment Genius: A Business Manager is required ...

Recruitment Genius: Operations Manager

£45000 - £55000 per annum: Recruitment Genius: This is an exciting opportunity...

Recruitment Genius: Panel & Cabinet Wireman

£20000 per annum: Recruitment Genius: Panel Wireman required for small electro...

Recruitment Genius: Electronics Test Engineer

£25000 - £27000 per annum: Recruitment Genius: An SME based in East Cheshire, ...

Day In a Page

A timely reminder of the bloody anniversary we all forgot

A timely reminder of the bloody anniversary we all forgot

Who remembers that this week we enter the 150th anniversary year of the end of the American Civil War, asks Robert Fisk
Homeless Veterans appeal: Former soldiers pay their respects to a friend who also served

Homeless Veterans appeal

Former soldiers pay their respects to a friend who also served
Downfall of Dustin 'Screech' Diamond, the 'Saved By The Bell' star charged with bar stabbing

Scarred by the bell

The downfall of the TV star charged with bar stabbing
Why 2014 was a year of technological let-downs

Why 2014 was a year of technological let-downs

Security breaches and overhyped start-ups dominated a year in which very little changed (save the size of your phone)
Cuba's golf revolution: But will the revolutionary nation take 'bourgeois' game to its heart?

Will revolutionary Cuba take 'bourgeois' golf to its heart?

Fidel Castro ridiculed the game – but now investment in leisure resort projects is welcome
The Locked Room Mysteries: As a new collection of the genre’s best is published, its editor Otto Penzler explains the rules of engagement

The Locked Room Mysteries

As a new collection of the genre’s best is published, its editor explains the rules of engagement
Amy Adams on playing painter Margaret Keane in Tim Burton's Big Eyes

How I made myself Keane

Amy Adams hadn’t wanted to take the role of artist Margaret Keane, because she’d had enough of playing victims. But then she had a daughter, and saw the painter in a new light
Ed Richards: Parting view of Ofcom chief. . . we hate jokes on the disabled

Parting view of Ofcom chief... we hate jokes on the disabled

Bad language once got TV viewers irate, inciting calls to broadcasting switchboards. But now there is a worse offender, says retiring head of the media watchdog, Ed Richards
A look back at fashion in 2014: Wear in review

Wear in review

A look back at fashion in 2014
Ian Herbert: My 10 hopes for sport in 2015. Might just one of them happen?

Ian Herbert: My 10 hopes for sport in 2015

Might just one of them happen?
War with Isis: The West needs more than a White Knight

The West needs more than a White Knight

Despite billions spent on weapons, the US has not been able to counter Isis's gruesome tactics, says Patrick Cockburn
Return to Helmand: Private Davey Graham recalls the day he was shot by the Taliban

'The day I was shot by the Taliban'

Private Davey Graham was shot five times during an ambush in 2007 - it was the first, controversial photograph to show the dangers our soldiers faced in Helmand province
Revealed: the best and worst airlines for delays

Revealed: the best and worst airlines for delays

Many flyers are failing to claim compensation to which they are entitled, a new survey has found
The stories that defined 2014: From the Scottish independence referendum to the Ice Bucket Challenge, our writers voice their opinions

The stories that defined 2014

From the Scottish independence referendum to the Ice Bucket Challenge, our writers voice their opinions
Stoke-on-Trent becomes first British city to be classified as 'disaster resilient' by the United Nations

Disaster looming? Now you know where to head...

Which British city has become the first to be awarded special 'resilience' status by the UN?