The significance and importance of controlled nuclear fusion reactors need not be said.

In the foreseeable future, fossil energy will be exhausted one day, according to the earth's current proven fossil energy reserves and consumption, oil can be used for about 40 years, natural gas for 80 years, and coal for 200 years.

But as fossil fuels are decreasing, the cost of extracting these energy sources will only get higher in the future, so almost all countries around the world have pinned their hopes for cheap energy on controlled nuclear fusion.

It is estimated that there are 0.03 grams of deuterium per liter of seawater, and there are 45 trillion tons of deuterium in seawater alone on Earth.

The deuterium contained in 1 liter of seawater, through nuclear fusion, can provide the equivalent of the energy released after the combustion of 300 liters of gasoline.

The nuclear fusion energy contained on the earth is about 10 million times that of the total nuclear fission energy that can be released by the elements that can be used for nuclear fission, which can be said to be an inexhaustible source of energy.

What's more, controlled nuclear fusion does not produce radioactive materials that pollute the environment, and can be carried out continuously and steadily in rarefied gases, which can be regarded as a model of safe and environmentally friendly energy.

Therefore, in a sense, controlled nuclear fusion has a much greater impetus for the energy revolution than metal batteries, but for cost, process and strategic considerations, Chen Xin is not ready to take out controlled nuclear fusion technology for the time being, unless the promotion of metal batteries in countries around the world is hindered in the future, he will sacrifice this combination of super killers.

As for now, the first thing he has to do is to build a nuclear fusion reactor with Steel.

The principle of a nuclear fusion reactor is simple and well understood.

Step 1. The mixture must be heated to the plasma state – that is, the temperature is high enough for the electrons to be free from the nucleus and the nuclei can move freely, so that the nuclei can come into direct contact, at which point a temperature of about 100,000 degrees Celsius is required.

In the second step, in order to overcome the Coulomb force, which is the repulsive force between the nuclei of the atoms that are also positively charged, the nuclei need to travel at extremely fast speeds, and the easiest way to get this speed is to continue heating. Bringing Brownian motion to a crazy level. For the nucleus to reach this operating state, a temperature of hundreds of millions of degrees Celsius is required.

Then it's simple, the nucleus of tritium and the nucleus of deuterium collide at a tremendous speed. New helium nuclei and new neutrons were produced. Unleashes a huge amount of energy. After some time. The reactor no longer needs to be heated by an external energy source, and the temperature of the fusion is sufficient for the nucleus to continue to fuse. As soon as the helium nuclei and neutrons are eliminated in time, a new mixture of tritium and deuterium is fed into the reactor. Nuclear fusion can continue, and a small part of the energy produced remains in the reaction body, maintaining the chain reaction, and most of it can be exported and used as an energy source.

It seems very simple, but there is only one question, where do you put this reactor that is hundreds of millions of degrees Celsius? So far, humans have not created any chemical structure that can withstand 10,000 degrees Celsius, let alone hundreds of millions of degrees Celsius.

That's why, 50 years after the hammer was made, humans have yet to effectively extract energy from nuclear fusion.

Well, human beings are very smart and can't solve problems with chemical structures, so let's use physical methods to experiment.

As early as 50 years ago, two theories of confinement of high-temperature reactants were developed.

One is inertial confinement, in which a mixture of a few milligrams of deuterium and tritium is loaded into a small ball about a few millimeters in diameter, and then a laser beam or particle beam is evenly injected from the outside, and the inner layer of the sphere is squeezed inward. The gas in the ball is squeezed, the pressure rises, and the temperature also rises sharply, and when the temperature reaches the required ignition temperature, the gas in the ball explodes, producing a large amount of heat energy. Such explosions occur three or four times a second, and if they continue continuously, the energy released can reach the level of millions of kilowatts. One of the founders of this theory is Wang Ganchang, a famous scientist in China.

The other is magnetic confinement, because the nucleus is positively charged, then as long as my magnetic field is strong enough, you can't run out, I build a circular magnetic field, then you can only follow the direction of the magnetic field lines, along the spiral movement, out of my range, and a little distance outside the annular magnetic field, I can build a large heat exchange device (at this time, the energy of the reactant can only be transmitted to the heat exchanger in the form of thermal radiation), and then use the method that human beings are already familiar with, to convert the heat energy into electrical energy.

Although the principle is simple, the power that can be achieved by existing laser beams or particle beams is still dozens or even hundreds of times short of what is needed, and various other technical problems make inertial confinement nuclear fusion out of reach.

Therefore, at present, the research of controlled nuclear fusion in countries around the world is mainly focused on the field of magnetic confinement.

In order to achieve magnetic confinement, a device that can generate a sufficiently strong annular magnetic field is required, and this device is called a "tokmak device" - TOKAMAK, which is an abbreviation in Russian for the prefix "toroid", "vacuum", "magnetic", and "coil".

As early as 1954, the world's first tokamak was built at the Kurchatov Institute of Atomic Energy in the former Soviet Union.

The progress seems to be very smooth, but it is not, because in order to be able to put it into practical use, the energy of the input device must be much smaller than the output energy, which we call the energy gain factor - Q value.

It was not until 1970 that the former Soviet Union obtained the actual energy output for the first time on the tokamak device that had been improved many times, but it was only measured with the most advanced equipment at that time, and the Q value was about 1 billionth.

Don't underestimate this part in a billion, which made the world see hope, so the whole world was inspired by this to build its own large tokamak installations, Europe built the Union Ring-JET, and the Soviet Union built the T20 (which later shrunk to T15, and the coil was smaller). But on superconductivity), Japan's JT-60 and America's TFTR (short for Tokamak Fusion Reactor).

Time and again, these tokamaks have set new records for energy gain factor (Q) values.

In 1991, the United Ring of Europe achieved the first deuterium-tritium operation in the history of nuclear fusion, using a 6:1 deuterium-tritium fuel mixture, and the controlled nuclear fusion reaction lasted for 2 seconds, obtaining an output power of 01,700 kilowatts and a Q value of 0.12.

In 1993, the United States used 1:1 fuel of deuterium and tritium on the TFTR, and the fusion energy released by the two reals was 03,000 kilowatts and 5,600 kilowatts, respectively, and the Q value reached 0.28.

In September 1997, the United European ring set a world record of 12,900 kilowatts. The Q value reaches 0.60. Lasted 2 seconds. Only 39 days later, the output power was increased to 16,100 kilowatts, and the Q value reached 0.65.

Three months later, the deuterium-deuterium reaction was successfully carried out on the Japanese JT-60. Convert to deuterium-tritium reaction. The Q value can reach 1. Afterward. The Q value exceeded 1.25 again. This is the first time that a Q value is greater than 1, and although the deuterium-deuterium reaction is not practical, the tokamak can theoretically actually produce energy.

In this environment. China is no exception, with several real tokamak installations built in the 70s – Gyre-1 (HL-1) and CT-6, followed by HT-6 and HT-6B, as well as the rebuilt HL1M and Gyro-2.

There is a saying that China's research on tokamak devices began with the donation of equipment from Russia, which is not true, and the construction of HT6/HL1 predates the HT-7 system donated by Russia.

Before HT-7, several of China's devices were ordinary tokamak devices, and the HT-7 donated by Russia was China's first "superconducting tokamak" device.

So what is an "ultra-tokamak device"?

In retrospect, the core of the tokamak device is the magnetic field, and to generate the magnetic field, a coil is used, and an electric force is required. The closer the tokamak device is to the practical use, the stronger the magnetic field, the greater the current to the wire, at this time, the resistance in the wire appears, the resistance makes the efficiency of the coil decrease, and at the same time limits the current through the guò, can not produce enough magnetic field, the tokamak seems to have come to an end.

Fortunately, the development of superconducting technology makes the tokamak peak loop, as long as the coil is made into a superconductor, the problem of high current and loss can be solved theoretically, so the tokamak device using the superconducting coil was born, which is the supertokamak.

So far, four countries in the world have their own large trans-tokamak installations: France's Tore-Supra, Russia's T-15, Japan's JT-60U, and China's EAST.

With the exception of EAST, the other four can only be called "quasi-super-tokamaks", and their horizontal coils are superconducting, while vertical coils are conventional, so they are still troubled by resistance. In addition, all three of them had circular coil cross-sections, and in order to increase the volume of the reactants, EAST made the first attempt to make a non-circular cross-section. In addition, the German Spiral Stone-7 is under construction, which is larger than the EAST, but the technical level is about the same.

Due to the huge costs required for the research of controlled nuclear fusion projects, it is difficult for any single country to bear them independently, so since 1985, the Soviet Union, the United States, Japan and the European Community jointly funded the establishment of the world's first experimental fusion reactor (ITER). (Note: ITER is no longer a tokamak device, but a test reactor, which is a big step forward)

The initial plan was to build a real yàn reactor in 2010 with a power output of 1,500 megawatts at a cost of US$10 billion.

Unexpectedly, because of the different ideas of various countries, and the collapse of the Soviet Union, coupled with the limitations of technical means, there was no result until 2000, during which the United States withdrew halfway, and ITER was in danger of stillbirth.

It was not until 2003 that the energy crisis intensified, and countries paid attention to it again, first China announced that it had joined the ITER program, and Europe, Japan and Russia were naturally happy, and then the United States announced its return plan. Immediately afterward, South Korea and India also announced their accession.

In 2005, ITER was officially established, located in Cadarashin, France, the basic design remains unchanged, and strives to be fully completed before 2015, with a cost of 12 billion US dollars, 40% of the European Union, 10% of France, China, Japan and the United States, and the rest want to be shared by others, but South Korea and India do not do it, and strive to let Russia also contribute 10%, and they will contribute 5%, and finally the United States, Japan, Russia, China, South Korea, and India will each contribute about 9%.

ITER means "road" in Latin, which shows how much hope people have for this thing. In all likelihood, she is the "way" for mankind to solve the energy problem.

If ITER succeeds, the next step will be to design and build a demonstration commercial reactor using ITER's technology, at which point it will not be far from true commercial fusion power generation. However, in the construction of ITER, there are still a large number of technical problems to be solved, and a prototype needs to be referenced, on this basis, the advanced superconducting tokamak device of various countries has become the blueprint for the design of ITER.

Of course, ITER's research is far from a tokamak device, and it still has many challenges to overcome.

Here we have to talk about the Q value (the ratio of output power to input power) problem, at present, all countries in the world can generally achieve the Q value of more than 1.5, but there are still two problems, which have not been solved by all countries at present.

The first is to provide the energy required for high temperatures without interruption. A Q value of 1.5 means that 100 tons of TNT-equivalent energy is required to produce 150 tons of TNT-equivalent energy, and it is continuous!

Second, even if you can supply power continuously, you put in 1 electricity, and it produces 1.5 heat and radiation, etc. And if you convert it into electricity, if the conversion rate is less than 66%, it is still a loss. At present, there is no breakthrough in this technology in the world.

Therefore, for people, the principle and scheme of controlled nuclear fusion are available, and the most difficult thing is in engineering technology, and this is precisely what steel is best at.

This is one of the reasons why Chen Xin is confident that he will build the world's first commercially operational reactor.

For example, in order to obtain a strong magnetic field, countries around the world generally use superconducting coils to confine high-temperature plasma, but the existing superconducting materials can only be maintained at more than minus 100 degrees Celsius to show superconductivity, and they must soak the magnet system in liquid helium, which not only increases the construction cost of fusion reactors, but also greatly limits the miniaturization of fusion reactors.

In addition, such as high-frequency current ignition and high-power laser ignition, these require a new generation of material process support.

But it doesn't matter for steel promium, which can now combine thallium, barium, calcium, copper, oxygen and other elements to create a superconductor at room temperature with a critical temperature of 340 K, that is, in more than 99% of the earth, this material can achieve superconductivity in the bare state.

As for the high-frequency, high-power lasers required for the ignition of nuclear fusion reactions, that is a piece of cake. (To be continued......)