Nuclear fusion, the term frequently encountered in the news for the past few days. The technology has been under the radar of physicists and engineers for a long time. Scientists have been trying to mimic the process of nuclear fusion under controlled conditions in the laboratory. Finally, there has been a major breakthrough in the area of controlled nuclear fusion. Very good news for mankind! Let’s understand how and why.
Humans, being the biggest consumers of energy on the planet, are on the constant hunt for affordable and clean energy sources. We have almost extinguished fossil-based fuels, thus exploring alternative sources of energy such as the Sun, wind, tides, biofuels, etc. All these sources have proven to be quite promising and efficient but demand very specific high-tech infrastructural facilities. Thus, the hunt for clean energy goes on. Of all the alternative sources of energy, there have been great advances in solar energy, but it has its own limitations and challenges. Nonetheless, the Sun is the ultimate source of energy for all life forms on Earth.
That being said, where does the Sun get its energy from? The answer is ‘Nuclear Fusion’ Not only the Sun but even the stars in our solar system derive their energy through the process of nuclear fusion.
What is nuclear fusion?
Nuclear fusion is a reaction in which neutrons of two light elements fuse under high pressure and at very high temperatures to make a heavier element, releasing a significant amount of energy during the process. The energy comes from the excess mass that is left over after the fusion of the two neutrons. The basis is the equation E=mc2, which demonstrates that mass and energy are interconvertible. In the nuclear fusion that occurs in the Sun hydrogen atoms fuse to make helium. Scientists have been trying to induce nuclear fusion using the two isotopes of hydrogen, deuterium and tritium. During the reaction, the deuterium nucleus fuses with the tritium nucleus, as a result, there is the formation of one helium nucleus, one free neutron, and energy. But the reaction requires very high pressure and temperature as high as 100 billion degrees Celsius.
Finally, a breakthrough!
After almost 50-60 years of pursuing nuclear fusion technology, scientists have been able to carry out fusion reactions in controlled laboratory conditions and produced energy as one of the resultant products. The experiment was done at National Ignition Facility at the Lawrence Livermore National Laboratory (LLNL) in California. It is said to be one of the biggest breakthroughs of our times that could revolutionise the energy sector. In this ground-breaking experiment, the scientists carried out a nuclear fusion reaction in a small peppercorn-sized capsule. The high temperature was achieved using a 192-beam laser that compressed and heated the hydrogen fuel. The temperature achieved was more than 100 billion degrees Celsius. The energy input was 2.05 megajoules and the output was 3.15 megajoules. Although the amount of energy produced is small, the technology has great scope in the future.
Why is nuclear fusion better than nuclear fission?
Fission is another nuclear process that is kind of the opposite of fusion, as in, it results in the breaking down of a heavier atom into lighter atoms. Fission releases energy as an end result of the process, but it also results in large amounts of long-lived radioactive waste which stays in the environment for a long time and is detrimental to humans as well as biodiversity. Nuclear weapons are based on the principle of nuclear fission. Nuclear fission plants have also been established for the production of electricity, but it poses the main challenge of radioactive material disposal. On the contrary, nuclear fusion does not release a significant amount of radioactive material. It only produces small quantities of short-lived radioactive waste that does not stay in the environment for a long time and is therefore considered relatively safe.
Nuclear fusion for a sustainable future
The achievement in the field of nuclear fusion is indeed great news for the energy sector. It offers several advantages over other energy sources being completely carbon-free, sustainable, and unlimited. Nonetheless, the project is still in its budding stage and there is a long way to go before nuclear fusion powers our homes.