Fusion power remains the ultimate energy prize
| Fusion vision: Prof Jeffrey Harris on top of the ANU's H-1NF
experimental fusion device in RSPhysSE. |
The perception of an impending world crisis in energy provoked by the oil price hikes in the 1970s was succeeded by concerns that carbon emissions would raise temperatures sufficiently to melt the ice caps and flood coastal regions. In recent years the hysteria has subsided with improvements in energy efficiency, a fall in energy prices and the moderation of estimates of future global warming. The fact remains, however, that fossil energy reserves are finite and the world's developing economies are increasing their energy usage.
Human beings have a long history of responding to challenges like this by inventing new technologies. Countries will have to develop locally-appropriate energy strategies combining higher efficiency and conservation with electric generation from solar, wind, hydro, geothermal sources and nuclear stations.
Probably the longest-term development will be required for nuclear fusion. Fusion is the ultimate energy engine of the universe, as it powers the stars and is responsible for the creation of all elements.
The most accessible fusion reaction involves the combination of two isotopes of hydrogen, the lightest element, to produce helium, the second lightest element, plus an energetic neutron which can be captured and used to heat water that powers a turbine generator. The attraction of fusion is that it uses abundant fuel - hydrogen isotopes found in water - and avoids the waste and other environmental hazards associated with nuclear fission.
There has been impressive progress in fusion research over the past 25 years. The most successful experiments so far use a doughnut-shaped chamber with a strong magnetic field to confine the hot, ionized gas (plasma) while it is heated to the 100 million degrees Centigrade required for fusion.
The production of power from such a system was demonstrated over the past three years at Princeton University in the US using a magnetic configuration called a tokamak, and there is a large tokamak project, the International Tokamak Experimental Reactor (ITER), being designed by an international team of scientists. However, it appears that ITER will result in a reactor too large and expensive to be commercially attractive. There is therefore parallel research to develop alternative ideas.
Australia is playing a role in this with a device called the H-1NF at the Research School of Physical Sciences and Engineering at the ANU. H-1NF is a magnetic device called a heliac, which is being used to investigate the physics of heating and confining the plasma. The H-1 device built by the ANU was selected by the government for additional funding of $8.7 million over five years, which will permit larger-scale experiments by Australian and foreign scientists.
The H-1NF project continues Australia's long history of research in fusion and plasma physics.
Professor Jeffrey Harris is Head of the ANU's Plasma Research Laboratory, at the Research School of Physical Sciences and Engineering