Fusion energy has potential for an inexhaustible energy resource.
A team of scientists in California announced a milestone in the decades-old quest to develop fusion energy last Wednesday. If harnessed successfully, fusion energy promises an unlimited energy source for future generations.
Unlike fossils fuels or nuclear fission, fusion opens the doors for abundant energy without radioactive waste, pollution, or greenhouse gases. The United States and other nations have invested many millions of dollars into fusion research, eager to exploit the potential that fusion energy has to offer. Fusion energy is not to be confused with the currently used nuclear fission energy, which is derived from splitting atoms.
Researchers at the federally-funded Lawrence Livermore National Laboratory revealed in the peer-reviewed journal Nature that, for the first time, an experiment yielded more energy out of nuclear fusion than was used in the fuel that created the reaction.
Led by physicist Omar Hurricane, the researchers described the achievement as significant, but said that more work is needed before nuclear fusion can be a viable energy source.
The experiment, however, did not produce self-heating nuclear fusion, otherwise known as ignition. Ignition is needed for any fusion power plant to be feasible.
The researchers used 192 lasers to ‘zap’ a small target containing a capsule approximately two millimetres in diameter filled with fusion fuel. The fuel consisted of deuterium and tritium plasma, which are two isotopes of hydrogen. At high temperatures, the nuclei of the deuterium and tritium fuse, and a neutron and something known as an ‘alpha particle’ emerges, releasing energy. These experiments created conditions up to three times the density of the sun.
Fusion power is generated by nuclear fusion processes. In fusion reactions, two light atomic nuclei fuse to form a heavier nucleus, which releases a large amount of energy. This is due to the strong nuclear force, which manifests as an increase in temperature of the reactants. This process is what powers stars, including our sun. Researchers have faced the daunting scientific and engineering challenges in trying to develop nuclear fusion for decades.
The Culham Centre for Fusion Energy, located in Britain, and the Princeton Plasma Physics Laboratory in New Jersey, United States, have taken a different approach to fusion energy. Their focus is on magnetic confinement, which entails putting plasma in a magnetic container and heating it until the nuclei fuse. Although research is promising, more work has to be done before full ignition can occur.