By Dr. Sajad Ahmad Mir
China’s “artificial sun” is not something like a star that China launches into the sky but is an experimental research device, HL-2M tokamak fusion reactor activated by the Chinese scientists which mimics the sun’s energy-generating process. The device is named as “artificial sun” because it replicates the nuclear fusion process carried out by the sun. It is installed at the Southwestern Institute of Physics (SWIP) in Chengdu, China. In other words, nuclear fusion on large scale is taking place in the sun and stars and Chinese scientists imitate the same on small scale in the fusion reactor project, HL-2M, a tokamak fusion reactor and thus gave the name of the reactor as artificial sun. The artificial sun is 11metres tall and has 8 metres of diameter and 30 tonnes of weight.
China’s HL-2M nuclear fusion reactor device previously set a record after it ran at 70 million degrees Celsius for 1,056 seconds and thereby smashed the record set by France’s Tore Supra tokamak device in 2003, where plasma in a coiling loop remained at similar temperatures for 390 seconds only. However, China’s artificial sun in May 2021 set new world record after it maintained a peak temperature of 150 million degrees Celsius for 101 seconds which is around 10 times hotter than the burning core of the actual sun in the sky.
This way such a scientific experiment laid a solid foundation towards running of fusion reactors in future. We all know that power generating nuclear reactors in a country are run by nuclear fission, a nuclear process of generating energy whereby a heavier nucleus is split into two lighter ones. Fission is easier to attain, but it produces waste. Nevertheless, based on HL-2M device, nuclear reactors in future will be run by nuclear fusion, a nuclear process of generating energy whereby two nuclei combine to form a heavy nucleus. Fusion is difficult to achieve, but it is considered a safer process with no nuclear waste. Therefore, nuclear fusion could potentially provide unlimited clean energy and relatively at very low costs. In both the nuclear processes,viz., fission or fusion, mass is converted into heat energy. In nuclear reactors, this heat energy in turn is used to generate electric energy/ power.
The main objective of the artificial sun is to create nuclear fusion reaction like in the Sun, using deuterium and tritium (isotopes of hydrogen) present in the sea water. So, the raw material for nuclear fusion reaction in the HL-2M device is well sourced with us. According to Einstein, mass can be converted into energy and vice-versa and can be scaled from his famous mass-energy equivalence relationship. For a layman, to keep it simple, Deutrium from only one litre of sea water can produce as much as energy equivalent to 300 liters of gasoline through nuclear fusion reaction. From this one can gauge the potential of artificial sun over the energy scale. For nuclear fusion to occur between two hydrogen atoms so that they fuse together to make helium and high amounts of energy (out of a part of the mass of hydrogen atoms), it needs either high temperature or high pressure (under gravity) or both. In the Sun 600 tons of hydrogen is fused per second to create helium and during this process a part of the mass of the hydrogen atoms converts into energy at extremely high pressures and under huge gravitational pressure. In the actual sun whereby both required high pressure for fusion reaction naturally exists under huge gravitational pressure of about 300000 million atmosphere and required high temperature of around 15 million degree Celsius is also naturally available in the burning core for fusion reaction. On the other hand in our planet, the earth, the required colossal pressure for fusion reaction is not possible, the earth being light in mass compared to the actual sun and thus small gravity, but required extremely high temperature as high as 100 million degree Celsius can be achieved as done by Chinese scientists in their fusion reactor project, HL-2M device/artificial sun.
Chinese scientists have been attempting to harness the power generated through nuclear fusion in the artificial sun for future generations provided it can be made extra sustainable particularly by maintaining the high temperature for a long period of time. They are trying to acquire infinite clean energy/power through nuclear fusion in the artificial sun. This way they can ease access to alternate energy source that too clean in nature and may reduce dependence on imported gasoline. Moreover, it may support their government to save trillions on imported fuel and help the country to prevent from energy/power price shocks at the international level. Nuclear fusion is likely the best way for humans to generate green energy. In contrast to nuclear fission based nuclear power reactors, nuclear fusion based reactors don’t produce any harmful radioactive waste and greenhouse gases and therefore, are extremely environment-friendly. Fusion is a very expensive process, but China’s tests could help researchers in their search for ways to reduce costs.
It is important to mention that China is part of the International Thermonuclear Experimental Reactor (ITER) facility built in Cadarache , South of France, which will become the world’s largest nuclear fusion reactor after it becomes operational. Many nuclear countries are a part of this project, including South Korea, Jepan, India, Russia and the United States. However, the China’s artificial sun will offer significant technical support to this facility and may take the lead role.
Our country must start China’s artificial sun or ITER like project without any further ado so as to compete with or outcompete rising global economies in clean energy production.
According to Barack Obama (2008) “Change will not come if we wait for some other person or some other time. We are the ones we’ve been waiting for. We are the change that we seek”
Dr. Sajad Ahmad Mir is a Sr. Lecturer Physics,BHSS Pampore, can be reached at sajadphysics@rediffmail.com
