Great Country Academician

Chapter 550:

The so-called controlled nuclear fusion, at the end of the day, is actually nothing more than a reaction in which two or more lighter nuclei agglomerate into one or more heavier nuclei and other particles.

During the long period of time when humans have been studying controllable nuclear fusion technology, although its mainstream direction is deuterium-tritium fusion, it does not mean that there are no other research directions.

Deuterium tritium, deuterium helium three, helium three/helium three, deuterium deuterium, hydrogen boron, etc. are all research directions.

The mainstream is deuterium-tritium fusion, just because this route is the easiest in theory.

In fact, in addition to these, carbon, oxygen, silicon, iron, gold, silver and other elements currently discovered by humans can, in theory, be fused.

It's just that with the iron element as the boundary, the light elements before the iron element fuse to release energy.

When it comes to iron, and elements after iron, fusion requires the absorption of energy.

This is why stars in the universe can only fuse into iron elements, and subsequent heavy elements, such as gold, require supernova explosions to form.

After iron and heavy elements after iron reach a certain mass, they will shrink violently under the action of gravity, releasing huge gravitational potential energy, forming a supernova explosion, and then forming various heavy elements.

Of course, the fusion of heavy elements is currently not something that human civilization can control.

Not to mention the fusion of heavy elements, it is the fusion of helium-3/helium-3. If magnetic confinement technology needs to be used to control it, the temperature of the plasma turbulence needs to be raised to more than one billion degrees. This is far beyond the current technological capabilities. Did it.

Therefore, there are actually not many options for miniaturized and controllable nuclear fusion technology.

In the office, listening to Liang Qu's inquiry, Xu Chuan smiled and said, "Among the fusion raw materials you mentioned, there are only two choices. You should know."

Hearing this, Liang Qu thought for a moment and then nodded, saying: "Helium-3/helium-trifusion can be ruled out first. The temperature required for pure helium-trifusion is too high, and the current technology cannot control it at all."

"The requirements for deuterium-deuterium fusion are also not low. Although theoretically the temperature requirements for pure deuterium fusion are not high, the cross-section of this fusion reaction is very small, and the products are mainly tiny neutrons, which is not suitable for reducing the size of the fusion reactor. requirements.”

"As for the rest, there are only the last two."

Xu Chuan smiled and nodded, saying: "Yes, the only remaining options are deuterium-helium fusion and hydrogen-boron fusion."

Hearing this, Liang Qu thought for a while and said: "If we want to simply put aside the influence of neutrons, hydrogen-boron fusion would be more suitable. From the perspective of fusion formulas and principles, hydrogen-boron fusion does not produce neutrons, and Although the products of deuterium-helium ternary fusion are mainly protons, there are still a small number of tiny neutrons produced."

Xu Chuan shook his head and said: "Compared to hydrogen-boron fusion, I prefer deuterium-helium fusion."

Hearing this, Liang Qu looked over curiously and asked, "How do you say it?"

Xu Chuan pondered for a moment and then said: "Although hydrogen-boron fusion is an ideal neutron-free fusion reaction, many technical difficulties need to be overcome to achieve it."

"And the stronger repulsion between hydrogen and boron-11 nuclei requires higher temperatures and pressures, which are theoretically higher than deuterium-helium ternary fusion."

"In addition, hydrogen-boron fusion does not produce neutrons at all. Your theory is based on inertial confinement fusion."

"Based on inertial constraint, after configuring the proportion of hydrogen and boron raw materials, there will indeed be no neutrons produced. But the method we use is magnetic confinement."

"On the basis of magnetic confinement, when hydrogen boron plasma operates in the reactor chamber, collisions and fusion reactions will also occur between hydrogen nuclei, thereby producing a small amount of neutrons."

"This is actually the same as deuterium-helium ternary fusion. The small amount of tiny neutrons produced in deuterium-helium ternary fusion also comes from the collision of deuterium and deuterium."

"So from a neutron perspective, there is not much difference between hydrogen-boron fusion and deuterium-helium ternary fusion."

Liang Qu thought for a while and said, "If we use deuterium-helium fusion, how to deal with the small amount of neutrinos produced during the fusion process?"

"These are neutrons produced by fusion reactions, which carry strong energy and cause great damage to equipment and materials."

Xu Chuan: "I don't have a good solution for this at the moment. Let's look at it based on experimental data later."

"But theoretically speaking, the neutrons produced by deuterium-helium fusion are very small in mass, far inferior to the neutrons produced by deuterium-tritium fusion, so the conditions for its protection are definitely not as high as those of deuterium-tritium fusion."

"The lower the conditions, the less materials we use to protect them. Every less material can free up some space."

After a pause, he continued: 'And the main reason why I consider deuterium-helium ternary fusion is actually not this. The reason why I consider using it is because of the fusion products. ’

"The products of hydrogen-boron fusion are helium and energy, while the products of deuterium-helium fusion are helium and protons. High-energy protons are the main products of deuterium-helium fusion, and they also contain a large amount of energy."

"Compared to the fact that most of the energy produced by deuterium and tritium fusion is in high-energy neutrons, high-energy protons do not damage materials and equipment and can be constrained by magnetic fields. Being constrained means that we can utilize them."

"Therefore, deuterium-helium ternary fusion is far more suitable for miniaturized fusion devices than other raw materials."

"It's not just miniaturized controllable nuclear fusion technology, this is actually the direction of second-generation controllable nuclear fusion technology."

"The tritium element used in the first-generation deuterium-tritium fusion has very little stock on the earth. It relies on lithium metal for tritium self-sustainment, but the stock of lithium metal is also limited on the earth."

"If deuterium-helium fusion technology can be completed on the basis of miniaturized and controllable nuclear fusion, the subsequent development of lunar projects will also benefit from it."

Deuterium-helium fusion was chosen as the primary direction for miniaturized controllable nuclear fusion technology, and the development of the moon was also one of the reasons.

As he said in the Nobel Lecture in 2018, only civilizations that yearn for the universe and the sea of ​​stars will have sufficient potential and future.

Hearing what Xu Chuan said, Liang Qu thought thoughtfully for a while, and then said: "If this is the case, then our next work is not only to complete the ignition operation of the stellarator to generate electricity, but also to verify that the stellarator can also achieve In addition to controllable nuclear fusion technology, the only thing left is to conduct experiments using deuterium and helium 3 as raw materials."

Xu Chuan nodded and said: "Yes, the next key work of the Energy Research Institute will be these two parts."

"I need you to collect more data on deuterium-helium triple fusion to determine whether it can be successful and how destructive the small number of neutrinos born is."

Hearing this, Liang Qu took a deep breath and nodded seriously: "I understand, then the next direction is these two pieces."

Xu Chuan smiled and said, "Then I'll leave it to you. Thank you for your hard work."

Liang Qu grinned and said: "No matter how hard it is, the hardest and most difficult part has been solved by you, Academician Xu. All we have to do is move forward based on the ideas you provided."

After a pause, he continued: "That's it for today. I'll arrange and adjust the work plan."

Xu Chuan smiled and said: "Well, I will complete the design and construction of the permanent magnet stellarator as soon as possible. After this part of the work is completed, I will probably devote the remaining time to the research of aerospace engines. ”

"The development of miniaturized and controllable nuclear fusion technology is left to you and the Energy Research Institute."

Liang Qu took a deep breath again, nodded solemnly, and responded: "Academician Xu, please rest assured that the Energy Research Institute will definitely complete its work."

Liang Qu left, Xu Chuan smiled and shook his head, gathered the manuscript paper on the table back, and continued his design.

Miniaturized controllable nuclear fusion technology is important, but this does not allow him to devote all his time to it.

For the development of aerospace and the exploration of manned moon landing projects, miniaturized controllable nuclear fusion technology is only part of it.

Human beings cannot walk on one leg. That is not called walking, that is called jumping.

And if you jump too much, you will easily fall.

In contrast, the design of the aerospace engine is also worthy of his time investment.

No matter which one of these two technologies appears alone, it will not cause much change in aerospace technology, but if they appear together, they will directly subvert the entire aerospace field.

Even, directly subverting the structure of the entire world.

After all, the rule of this world is that no matter how technology develops, only those with big fists can grasp the truth.

After leaving the development of miniaturized and controllable nuclear fusion technology to the Energy Research Institute, Xu Chuan stopped taking care of it.

The technology of the permanent magnet stellarator in his hand took him a whole week to complete the concept. The data was immediately sent to Huaguo Fusion Energy Power Co., Ltd., which is the Dawn Demonstration Reactor Project, through the Supercomputing Center. Perform verification and subsequent adjustments.

This part of the work cannot be rushed and will take a relatively long time to complete.

After all, what is involved is a controllable nuclear fusion reactor. If there are problems with the concept and reactor structure, the consequences will be disastrous.

It is not impossible for an accident to occur in a plasma operation experiment to a direct explosion of a fusion reactor.

So after finishing his work, Xu Chuan was not in a hurry. After leaving the rest of the work to the supercomputing center, he came to the Institute of Aerospace Research.

Aerospace engines are also his focus.

In the research institute, Xu Chuan found Weng Yunzong who was working.

Unlike the staff of the other three major research institutes, the head of the Aerospace Research Institute, Weng Yunzong, was transferred from the Sichuan Aerospace Research Institute.

Not only the person in charge, but also many researchers at the Aerospace Research Institute were transferred or poached from Sichuan Space Base and Jiuquan Aerospace Research Institute.

In the office, Weng Yunzong was stunned for a moment when he saw Xu Chuan walking in after knocking on the door, and then stood up to greet him with a smile on his face.

"Academician Xu, you are here."

Xu Chuan smiled and said: "I have been busy with other aspects of work recently, so I haven't come here much. Let's talk to me about the specific research situation of aerospace engines."

Weng Yunzong nodded and said with a smile: "No problem."

In response, he called his assistant to make two cups of tea, handed one cup to Xu Chuan himself, and said with a smile: "As for the design of the aerospace engine, it is going well for the time being."

"According to the ideas you provided before, Academician Xu, we have completed the general design drawings. Do you want to take a look?"

Hearing this, Xu Chuan's eyes showed curiosity and interest. He nodded quickly and asked in surprise: "Is it so fast?"

Although I know that domestic research institutions have strong ability to expand based on ideas and theories, it is still surprising that they can come up with the design of an aerospace engine so quickly.

After all, this is a brand-new engine design that is separate from the electromagnetic propulsion system. It needs to be redesigned in terms of strength, electromagnetic propulsion, thrust, structure, etc.

As for the design of aerospace engines, even if the theory has been completed, its complexity still often takes an extremely long time to solve.

Strictly speaking, I don’t know how long it will take to develop a new engine, because it requires a lot of preliminary basic research and key technology research.

If we only count from the start of the project, it is estimated to be at least ten years. If the technology is readily available, it will take about ten years to produce a product.

For example, the F119 turbofan engine installed on F-22, F-35 and other fighter jets in the United States took a full eight years from development to design.

Of course, the design of an aerospace engine is far less complex.

On the one hand, it has a theoretical basis and advancement, and can be transformed through Hall thrusters and electromagnetic thrusters.

On the other hand, it has no requirements for maneuverability, agility, high stealth, supersonic cruise and short take-off and landing capabilities, which are the requirements of a fighter aircraft.

After all, its current main purpose is the space shuttle, and the only requirement is that the thrust is large enough.

Without these stringent requirements, the design of the drawings is naturally much simpler.

However, the speed at which it can be produced in just a few months is quite surprising.

Weng Yunzong said with a smile: "On the one hand, we have poached many talents from major aerospace agencies, and on the other hand, Academician Yang Hong has given us a lot of help."

"Academician Yang Hong provided a lot of information and detailed data on the Hall propulsion unit on Tiangong, which greatly simplified our design work."

Xu Chuan nodded and said, "I'm sorry to trouble Academician Yang. Please take me to see the design drawings."

Academician Yang Hong is the chief designer of the Tiangong Space Station. He and the other party came up with the direction and design of the aerospace engine.

Weng Yunzong nodded, stood up and said, "It has indeed caused a lot of trouble to Academician Yang. He also refused the reward offered to him by the institute."

Xu Chuan said with a smile: "I have talked with Academician Yang before. If our aerospace engine is built, he hopes that it can be applied to his space station in the first batch."

Weng Yunzong suddenly said "Oh", nodded, and said with a smile: "So that's how it is."

He was still wondering before why the chief designer of the Tiangong Space Station was so concerned about their aerospace engine project. The original point was here.

To be honest, considering the current academic environment in China, it would be great to be able to exchange some things with you. Someone like Academician Yang, who provides various data and technologies for free, is just dreaming without red-headed documents.