Nuclear fusion: the future of energy production

Most of the energy entering the Earth's biosphere comes from fusion occurring in the Sun. On 28 June this year the six largest global economic powers agreed to jointly fund the next step towards harnessing the same process on Earth to provide cheap and plentiful energy for society. Australia, despite its role in the founding of fusion science and its ever-present interest in our environmental well-being, was not part of this agreement. Fusion power research is working to provide a virtually limitless, industrially useful and environmentally harmless energy source with zero greenhouse gas emissions and no threat of nuclear weapons proliferation. The only exhaust gas is helium, which is naturally lost to space and cannot represent a long-term atmospheric contaminant on Earth. For fusion researchers, the promise of cheap, safe energy is one that 30 years of intensive research has yet to achieve. The problem is simple: how do you push minuscule nuclei close enough together so they fuse and release energy? Only the Sun's gravity does this - the gravity on Earth is too weak. Scientists cannot manipulate the force of gravity to mimic the Sun, and therefore they must find another way to make nuclei merge. For very short times the nuclei can be pushed together by intense lasers. Sustained reactions involve accelerating the nuclei so fast that they merge in a collision. This means heating the fuel mixture to extremely high temperatures. The easiest fusion reaction uses deuterium (D) and tritium (T) ions for fuel