China hopes to realize "artificial sun"


On October 19, 2022, there was exciting good news: China's new generation of controllable nuclear fusion experimental device (HL-2M), known as the "artificial sun", has made a breakthrough in operation, creating a high temperature of 150 million degrees Celsius and a plasma current of more than 1 trillion amperes (1 million amperes), which has met the ignition requirements of nuclear fusion, and the necessary conditions for the stable operation of nuclear fusion have been met. On April 12, 2023, China's "artificial sun" set a new world record, successfully achieving stable plasma operation for 403 seconds, which is of great significance for improving the economy and feasibility of nuclear fusion energy and accelerating the realization of nuclear fusion power generation.

In order to obtain the most ideal ultimate energy source for mankind, scientists have been trying to imitate the nuclear fusion reaction on the sun for decades and build a device to provide clean energy for mankind, so the nuclear fusion experimental research device is known as the "artificial sun". China's "artificial sun", which is at the forefront of the world's research and development, will release a brilliant and dazzling light in people's expectations!

Speaking of which, people naturally wonder why it takes huge manpower, material resources and time to develop an "artificial sun" when the sun already exists?

This is because the world's existing energy sources have challenged humanity: the most commonly used fossil fuels (such as coal, oil and natural gas) have limited reserves, are in danger of being depleted in the future, and there is a certain amount of environmental pollution. Green new energy sources such as wind, solar, and hydro energy are limited by weather or geographical conditions, making it difficult to meet the long-term needs of human beings for energy. As for the many nuclear power plants that have been built in various countries around the world, they use nuclear fission reactions to generate electricity, and they require small reserves of nuclear fuel such as uranium and plutonium, and they also produce radioactivity. The "artificial sun" uses nuclear fusion reaction, one of the raw materials required for deuterium has huge reserves on the earth, almost inexhaustible, and the products of nuclear fusion reaction are environmentally friendly and not harmful, so nuclear fusion energy is considered to be the most ideal "ultimate energy" for human beings.

The "artificial sun" is a device built on the principle of nuclear fusion reaction on the sun to provide clean and cheap electricity for mankind. The "artificial sun" built in China is the fully superconducting tokamak nuclear fusion experimental device (EAST), which is a ring-shaped container that controls nuclear fusion reactions. In order to achieve a nuclear fusion reaction and create a "little sun", it is first necessary to reduce the distance between the nucleons (i.e., protons and neutrons) in the nucleus of hydrogen (in fact, the two isotopes of hydrogen, deuterium and tritium) to a range that can bring the nucleons close to the nuclear force to interact.

However, since atomic nuclei are all positively charged, there is a large electrostatic repulsive force between atomic nuclei. To bring them close to the range of nuclear force, the nuclei participating in the nuclear fusion reaction need to first obtain sufficient kinetic energy, that is, the nuclei are polarized. Large kinetic energy violently collides and compresses each other, thus forming a nuclear fusion reaction. In the military, people use the high temperature and pressure generated when an atomic bomb explodes in a nuclear fission reaction to cause a nuclear fusion reaction of deuterium and tritium to make a hydrogen bomb that is much more powerful than an atomic bomb.

Usually, the way to obtain strong kinetic energy for atomic nuclei is to use a strong current to discharge the nuclear fusion fuel deuterium and tritium (gas), which will produce high temperatures of tens or even hundreds of millions of degrees Celsius. At such a high temperature, the electrons outside the nucleus have completely separated from the nucleus, and at the same time, deuterium and tritium are separated into positively and negatively charged ions, that is, a burning plasma is formed. These high-speed, high-temperature plasmas collide with each other and bombard the ring-shaped container wall of the nuclear fusion device, thereby igniting a nuclear fusion reaction.

A strong magnetic field can make the charged ions at high temperature converge into thin columns without scattering, so that the nuclear fusion reaction can be carried out as needed, that is, the speed of the nuclear fusion reaction can be controlled. During the nuclear fusion reaction, the nuclei of deuterium and tritium fuse with each other to produce helium and neutrons. These high-energy neutrons will heat the turbine power generation system in EAST, thereby generating powerful electricity. The power generation process is safe and does not produce radioactive materials like ordinary nuclear power plants.

So, if the "artificial sun" successfully operates in the future, what changes and benefits will it bring to the world?

Scientists answered this way: First of all, the challenges and crises facing energy will be solved, the price of energy will be very low, and some projects that are difficult to carry out due to energy consumption restrictions, such as seawater desalination and desert control, can be carried out on a large scale, thus bringing about Huge progress in production and life.

Secondly, the nuclear fusion products of the "artificial sun" are helium and neutrons, which do not emit harmful gases. The greenhouse effect, haze and acid rain caused by environmental pollution will be greatly reduced or even eliminated, thereby completely improving the ecological environment.

In addition, deuterium, the raw material for nuclear fusion energy, can be obtained from abundant seawater. One liter of seawater contains 0.03 kilograms of deuterium. The energy released by these deuteriums through nuclear fusion reactions is equivalent to the heat energy released when 300 liters of gasoline are burned. The reserves of deuterium in the global ocean can reach hundreds of thousands of tons, enough for human use for billions of years, which can solve the energy problem once and for all.