Fusion breakthrough offers hope for clean energy source

Nuclear scientists using a bank of lasers the size of three football fields have generated a huge amount of energy from fusion, possibly offering hope for a clean energy source.

The array of almost 200 laser beams was focused on a tiny spot to create a mega blast of energy - eight times more than ever before.

Although the energy lasted for just 100 trillionths of a second, it took scientists closer to the ultimate in fusion ignition, the moment they create more energy than they are using.

"A historic advance for inertial confinement fusion research," said Kim Budil, director of the Lawrence Livermore National Laboratory, which operates the National Ignition Facility in California where the experiment took place.

Nuclear fusion is seen by some experts as energy of the future, particularly as it produces little waste and no greenhouse gases.

It differs from fission, a technique currently used in nuclear power plants, where the bonds of heavy atomic nuclei are broken to release energy.

In the fusion process, two light atomic nuclei are "married" to create a heavy one, while in this latest experiment scientists used two isotopes of hydrogen, giving rise to helium. This is the process that is at work in stars, including our sun.

But Jeremy Chittenden, a co-director for research at Imperial College London, cautioned: "Turning this concept into a renewable source of electrical power will probably be a long process and will involve overcoming significant technical challenges."