Of all the futuristic technologies scientists have sworn would change our lives forever, none is more promising, and more elusive, than fusion power. Fusion is a great choice because we know it can produce a lot more energy than most efforts we now use. We have no greater evidence than our own stars and the sun.
A star can produce billions of years worth of energy and can do it cleaner than current fission nuclear reactors. Even better we can reproduce fusion artificially. The goal now is to reproduce an economically viable fusion reactor that can produce energy on a commercial scale.
Fusion works by essential fusing atoms together into a new atom. The energy released comes from the strong and weak forces that holds the nucleus of an atom together. We know that when an atom is split in the process called fission is quite powerful. Think about the energy that can be released when two nuclei of two whole atoms are fused together. The energy yield is even greater.
At the moment the availability of fossil fuels limits mankind’s ability to pursue advanced projects such as interplanetary or even interstellar travel. Fusion is one of the possible sources of energy that scientists are looking at.
The well-publicized failures of cold fusion may have tainted the field’s reputation, but physicists have been successfully joining nuclei with hot fusion since 1932. Today, research in hot fusion could lead to a clean energy source free from the drawbacks that dog fission power plants. Fusion power plants cannot melt down; they won’t produce long-lived, highly radioactive waste; and fusion fuel cannot be easily weaponized.
At the forefront of the effort to realize fusion-based power is ITER, an international collaboration to build the world’s largest fusion reactor. At the heart of the project is a tokamak, a doughnut-shaped vessel that contains the fusion reaction. In this vessel, magnetic fields confine a plasma composed of deuterium and tritium, two isotopes of hydrogen, while particle beams, radio waves and microwaves heat it to 270 million degrees Fahrenheit, the temperature needed to sustain the fusion reaction. During the reaction, the deuterium and tritium nuclei fuse, producing helium and a neutron. In a fusion power plant, those energetic neutrons would heat a structure, called a blanket, in the tokamak and that heat would be used to turn a turbine to produce electricity.
The ITER reactor will be the largest tokamak ever made, producing 500 megawatts of power, about the same output as a coal-fired power plant. But ITER won’t generate electricity; it’s just a gigantic physics experiment, albeit one with very high potential benefits. A mere 35 thousandths of an ounce of deuterium-tritium fuel could produce energy equivalent to 2,000 gallons of heating oil. And ITER’s process is “inherently safe,” says Richard Pitts, a senior scientific officer on the project. “It can never, ever be anything like what you see in the fission world–in Chernobyl or Fukushima–and this is why it is so attractive.”
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