Nuclear fusion is the process by which atomic nuclei fuse together to form heavier nuclei, releasing enormous amounts of energy in the process. The universe itself is largely powered by nuclear fusion, as this is the process that powers the stars. Without nuclear fusion, stars could not exist. What is nuclear fusion and will humanity ever be able to use it to produce energy?
How Nuclear Fusion Works
Nuclear fusion can only occur at very extreme temperatures and pressures. The temperature at which nuclear fusion can occur is 100 million degrees Celsius. This is why nuclear fusion usually only occurs in the cores of stars. High temperatures are needed to keep atomic nuclei moving at high speed so that they can stick together on impact, while higher pressures ensure that the nuclei remain in a relatively small area so that fusion can occur. For example, the pressure and temperature in the Sun’s core are so high that individual hydrogen nuclei fuse together. The nucleus of hydrogen is one proton, and in the core of every star, these protons collide with each other and merge. One of the protons on impact will decay into a neutron, resulting in the formation of what is called deuterium, which is simply hydrogen nuclei that also contain a neutron. When two deuterium nuclei fuse together, they produce helium, which has two protons and two neutrons. Interestingly, not all deuterium turns into helium. For example, the Sun converts about 620 million metric tons of hydrogen into 616 million metric tons of helium every second. This four million difference is released as energy in the form of an alpha particle and electromagnetic radiation.
Nuclear fusion leads to a process known as nucleosynthesis, in which every element, down to iron, is produced in the cores of the most massive stars. While hydrogen fusion is what powers stars, each star contains only a limited amount of hydrogen. As hydrogen turns into helium, the star will begin to turn helium into even heavier elements such as oxygen, carbon and nitrogen. The mass of the star will determine which elements will form. The higher the mass of a star, the higher the temperature and pressure in its core. As a rule, stars with a large mass continue the process of fusion until the formation of iron. The fusion of elements lighter than iron will produce a huge amount of energy, but the fusion of iron requires more energy than is released. Thus, iron is an energy absorber, not an energy emitter. Once iron is formed in the core of a star, it quickly runs out of energy and collapses under its own gravity, eventually exploding as a supernova.
Fusion vs Fission: What’s the difference?
Both fusion and fission have similar names, but they are two completely different ways of producing energy. Fusion is the process by which individual nuclei fuse together and release energy. Meanwhile, fission is a process in which unstable radioactive elements break apart with the release of energy. While fusion usually deals with light elements such as hydrogen and helium, fission uses radioactive materials such as uranium and plutonium. Moreover, fission produces radioactive waste as a by-product, while hydrogen fusion produces only helium as a by-product. Synthesis is also a much more energetic process than fission.
Will humans ever use fusion to generate energy?
Humanity is still heavily dependent on the use of fossil fuels for its energy needs. Fossil fuel production has skyrocketed in the last century as the world’s population has grown exponentially. Although the use of fossil fuels has boosted the economies of some countries and provided mankind with access to vast amounts of energy, using them as an energy source has obvious disadvantages. Things like climate change, global conflicts and the possible depletion of fossil fuels are all problems associated with their use. While renewable energy sources are on the rise, none of them are close enough to replace fossil fuels as humanity’s primary source of energy. However, what if there was a pure form of energy that could supply us with an unlimited amount of energy almost forever? Look no further than nuclear fusion.
Nuclear fusion offers humanity a potential solution to all of its energy needs and problems. For example, the Sun produces more energy from nuclear fusion every second than humanity could produce in tens of thousands of years. Hydrogen is also a very common element on Earth and only small amounts would be needed to produce massive amounts of energy. The only by-product of nuclear fusion is helium, which is an inert gas that can be captured and used in other industrial processes. There is no nuclear waste and no greenhouse gases. Fusion energy would also be extraordinarily cheap, as there would be too much energy to use. Although mankind has managed to produce nuclear fusion in laboratories, scientists have not yet developed a thermonuclear plant capable of generating energy. Rather, fusion laboratories absorb more energy than they produce, but this may change in the near future. Scientists are constantly breaking records for the amount of energy produced in fusion reactors, and it may only be a matter of time before we have a full fledged fusion reactor capable of producing energy.