이름 or 단체명
Nepean High School
[Group 3] 7. 에너지 8. 일자리와 경제 성장 9. 혁신과 인프라
Artificial Sun / The new revolutionary energy source
SDGs : Energy
Artificial Sun, also known as the tokamak is the new, revolutionary energy source that is very efficient and safe. Artificial Sun is the future of our energy, that will make the earth healthy. -
Fossil fuels are running out on earth, yet 81% of the worldwide population is using fossil fuel as their main source of energy. This is not a sustainable source of energy to power the earth. As a result, scientists have been developing devices that could collect energy from wind, sun, and water. These are sustainable and safe ways of collecting energy but they have low efficiency. Therefore, scientists have come up with the innovative idea of creating an artificial sun, ITER—powered by nuclear fusion—to make clean, safe, sustainable, and most importantly, efficient energy.
ITER is on track to be the world’s largest artificial sun, a project in which seven major countries jointly construct and operate a large-scale superconducting nuclear fusion laboratory to explore a safe and sustainable new mode of harnessing energy. Artificial suns that already exist can be seen as prototypes for ITER because ITER is a device that both creates ultra-high fusion plasma and has the ability to test whether or not this can be used to make electricity. ITER is currently built in Saint-Paul-lès-Durance, which is located in southern France. The major parts of ITER are produced in different countries, and are shipped to France. It is defined as one of the world’s biggest artificial suns because the main parts of ITER can weigh between 500 and 5000 tonnes. To move the gigantic parts, they use ships and the components usually enter France through the Marseilles Fos port. There, they have an exclusive road that stretches 104km for ITER. Scientists started to design ITER in 2007, finished the design in July of 2008, and all the parts for building have arrived in France in June 2020. Their goal is to finish building it by 2025 and be able to prove sustainable energy production in the 2040’s.
ITER, the project to make the biggest artificial sun, is based off of a device called an experimental superconducting HL-2M Tokamak. The Tokamak began its construction in 2006, and was just recently tested on December 4th, 2020. It is considered the world’s first fusion reactor. The Tokamak aims to provide a sustainable and reliable man-made source of energy in a time where the world’s natural resources are being depleted. The Tokamak runs by the same principle underlying solar energy. It uses powerful magnetic fields directed at a confined plasma core in the shape of a torus to safely move and direct particles. The magnetic fields are generated by a series of coiled structures that surround the torus core. The first magnetic field is called the poloidal field created by the outer pollodial coils and the second magnetic field is called toroidal which is created by the toroidal field coils. The science behind the Tokamak is based on the principle of nuclear fusion. Nuclear fusion occurs when two or more atomic nuclei are bombarded with enough energy that they combine to form other atomic nuclei and subatomic particles. This process naturally occurs in the core of the sun where the gravitational pull of the sun causes hydrogen gas to be under high pressure. The result is nuclear fusion, where four hydrogen nuclei combine to form helium as energy is released in the form of light. The Tokamak takes advantage of oppositely charged electrons travelling at extremely high velocities within the fusion plasma at very high temperatures. The magnetic field imparted by the coiled structures confine the plasma particles to the torus, while several auxiliary heating methods increase the plasma particles under conditions that permit fusion to occur, similar to the natural sun. To achieve a similar reaction to solar fusion on Earth, these specific conditions must be achieved. There must first be extremely high temperatures that allow high-velocity collisions to occur. Since there is not enough pressure here on Earth to facilitate nuclear fusion, scientists compensate for this by increasing the temperature at the site of activity. This is why the core torus contains extremely hot plasma that can reach temperatures as high as 150 million centigrades. Then, there must be enough plasma particle density, which is a necessary condition to increase the probability for these collisions to occur, and there must be a Finally, specific confinement time of the plasma within a defined volume, which will keep the plasma in place and prevent it from expanding. With these conditions, electrons separate from the nuclei and transform it into plasma - an ionized state of matter resembling gas. The plasma contains charged particles (positive nuclei and negative electrons) which allow for an environment where particles of light can fuse and provide energy. The structure surrounding the torus is designed to absorb the uncharged neutrons from the fusion plasma and transfer the kinetic energy into heat. As with conventional energy power plants, the heat is used to produce steam and eventually electrical energy by generators and turbines.
The artificial sun has a lot of advantages and it is revolutionary for many different reasons. Burning fossil fuels are extremely toxic because they contribute to the increasing levels of greenhouse gases in the atmosphere, namely to the increasing levels of carbon dioxide in the past half century. Conversely, the artificial sun is carbon-free, meaning it does not rely on the production of greenhouse gases as a byproduct of its reaction. Additionally, current nuclear energy resources rely on the splitting of atoms, and this generates nuclear wastes. Moreover, solar panels are not efficient on cloudy days since they have to absorb sunlight in order to produce energy. Also they have a really low energy efficiency because they are made in a way that it loses a lot of energy when changing light energy to the energy that we can use. The Artificial sun could produce the same amount of energy with a glass of sea water as a barrel of oil. The artificial sun uses lithium, and helium-2 as it’s fuel, which it could be easily found in sea water. This makes artificial sun a great source of energy since seawater is plentiful and a renewable source of energy. With the nuclear plants, if the fuel is in, we have to wait until it all burns out. So if not monitored carefully, accidents like the Fukushima nuclear disaster. With the artificial sun, it is very safe because we are the ones that put in the fuel, so if something happens we can just shut it off right away. Also nuclear plants, which split atoms, make nuclear waste as a by-product that is very dangerous. The by-product of artificial sun is water and helium, therefore it’s much more safe. Thus, though the artificial sun is very expensive to make and it is uncertain that it could produce energy properly, countries are cooperating to create it because it is a safe, long lasting, and eco-friendly source of energy.
Although the energy potential of the tokamak is incomparable to any other energy sources that we use, there are still many challenges facing this technology. Perhaps the most evident challenge with the tokamak is how expensive it is and how much funding is required for its ongoing research and construction. Another major challenge is ensuring that all the tokamaks pass safety tests, especially as the technology continues to grow and becomes even stronger. The tokamak generates large amounts of energy, and although the walls of the tokamak are designed to absorb the energy and convert it into heat, extra safety precautions must be ensured to prevent accidents and protect people from danger. Along with the incredible amount of energy that the tokamak produces, it is all converted into heat. In fact, the plasma can reach temperatures of up to 150 million centigrades. This heat has the ability to damage the surrounding infrastructure. Similarly the high-velocity plasma particles can cause damage to surrounding buildings as well as human tissue if not properly contained. These safety precautions are crucial considerations to take since the tokamak is an extremely high-energy technology. Apart from the safety aspect of the tokamak, there are also some technological challenges that scientists and physicists are still attempting to resolve. Although the tokamak is generally regarded as waste-free, this isn’t necessarily true. Streams of energetic neutrons will bombard the walls of the tokamak from which 98% will end up being radioactive waste. The remaining 2% will actually be intercepted for testing of tritium production in lithium.
The HL-2M Tokamak began its construction in 2006, and by 2020 has been officially tested and activated its completed nuclear fusion reactor. China projected plans that include establishing commercial production of fusion energy by the year 2050, while ITER aims to finish their project by 2025. This will have an enormous impact on China’s energy and national economy. Its impact will reach the rest of the world as well because the artificial sun is predicted to lead the global demand for sustainable energy and clean development. Improvements needed for the optimization and safety of the device, as well as the numerous tests will prove to be quite costly and risky in the next several years before the artificial sun becomes commercially available. One issue in particular with the Tokamak is the general instability that comes with the confinement of plasma. The plasma can face ‘disruptions’ caused by the plasma that undergoes displacement and general instability. Plasma instability is an issue that is being addressed by careful design of the Tokamak, and will prove to be a challenge in the upcoming year as the design for the Tokamak is perfected. Another issue going forward inherent in nuclear fusion reaction is the issue of overheating, particularly in this case, plasma overheating. Scientists are working on solutions to manage the plasma heat by controlling the supply of electrical pulses supplied to the electrical conductor—the plasma. However, there are limitations to the pulses and so the Tokamak can only operate for short periods of time, or scientists must find another way of heating and current drive. The artificial sun has an exciting future in renewable energy, but until then there are still several areas of improvement.
The tokamak harnesses the power of natural fusion and by using powerful magnetic fields to confine hot plasma in a torus. This technology generates large amounts of heat which is used to produce steam and eventually electricity. The artificial sun holds promise for a more sustainable and green future. As natural resources are being depleted and climate change drastically changes the face of the Earth, a greener solution is urgently needed—and the artificial sun optimistically offers that.