The holy grail for researchers in power generation is nuclear fusion. It promises the clean power of conventional fission with the safety of non-nuclear technology.

One kg of fusion fuel would produce the same amount of energy as 10,000,000kg of fossil fuel. There are no chain reactions, no production of radioactive actinides and the radiotoxicity of fusion waste materials decays rapidly.

But there are still two major hurdles to overcome. One is containing the tremendous heat given off by fusion, 100 million degrees centigrade; the other is generating sufficient power for the fusion process.

One answer to the heat problem is to contain the reaction within a magnetic field so it does not touch the sides of the reactor vessel and UK scientists are developing such systems.

Now, scientists at America's Sandia National Laboratories' Z machine facility are developing an answer to the second hurdle - power needs.

In collaboration with researchers at the Institute of High Current Electronics in Tomsk, Russia, they have created a linear transformer, which features lower inductances so it is able to produce very short, 100-nanosecond, pulses.

Their system is based on a switch tightly coupled to two capacitors. It is about the size of a shoebox and is termed a brick. When bricks are tightly packed in groups of 20 and electrically connected in parallel in a circular container, the unit can transmit a current of 0.5 megamperes at 100kV.

Because these modules can be stacked, it should be possible to generate 60 megamperes and six megavolts of electrical power, enough to generate high-yield nuclear fusion within the parameters necessary to run an electrical power plant.

"This is the most significant advance in primary power generation in many decades," says Keith Matzen, director of Sandia's Pulsed Power Centre.

Since 1949, Sandia National Laboratories has developed science-based technologies that support US national security in areas such as nuclear weapons and defence systems.

Sandia National Laboratories