Great Country Academician

Xianlin campus, in the industrial building.

It was the second time he came here, and this time Xu Chuan took a special look at the office situation in the building.

In the past two months, under the leadership of Academician Peng Hongxi, the recruitment of personnel and the work of project research have been fully launched.

Along the way, he saw several different groups of researchers gathered in different places to discuss something.

Of course, he didn't look closely.

As a general manager, he only needs to control the direction of the project and solve the most difficult problems.

As for those other problems, someone still has to work.

He is just a person, not a god. It is impossible to do everything in a super project like controllable nuclear fusion.

All the way to Peng Hongxi's office, Xu Chuan knocked on the open door.

Inside, Peng Hongxi was sitting at his desk dealing with work. When he heard the knock on the door, he looked up, and then a smile appeared on his face.

Putting down the pen in his hand, he stood up with a smile and greeted: "Academician Xu is here. Congratulations, you have broken another record and achieved the title of academician of the two academies in one day."

Xu Chuan smiled and said, "Old lady Peng, you are too polite. In front of you, I am just a junior."

Peng Hongxi said with a smile: "Those who are masters come first, your knowledge and abilities have already far surpassed us old men."

After exchanging pleasantries, Xu Chuan got to the point, and said, "Let's not talk about that, I don't think I will have much time to come this time, and there are many other things to be busy, and Mr. Peng must have a lot of things on his hands."

"What about the previous plasma turbulence control model? Take me to have a look. If there is no problem, I have to apply to the above supercomputer for verification. There are still many things to do in the future."

Peng Hongxi nodded, got up and said: "Come with me, the model optimization has been done almost, but I don't know if it has met your requirements."

Xu Chuan: "Look at it first, and then change it if it doesn't work."

"For controllable nuclear fusion, the control of plasma turbulence in the chamber is a major event. There is no rush, and it must be ensured that nothing goes wrong."

Following Peng Hongxi, the two arrived at the seventh floor.

"Zhou Ji, Xia Guang, you two come over here."

Peng Hongxi called out to the crowd who were busy in front of the computer in the office, and soon two middle-aged men stood up and walked over quickly.

Immediately, he, Xu Chuan, introduced: "In the office on the seventh floor are the researchers on mathematical and physical models that you specially arranged to recruit. They are all here, a total of twelve people."

"In the past two months, they have been cooperating with the professor of plasma to optimize the model."

"Zhou Ji and Xia Guanghe are currently in charge, one in charge and one in charge."

"Director Zhou Jizhou was originally an elite from the Chinese Academy of Sciences, mainly in plasma modeling."

"Xia Guang graduated from the University of Science and Technology of China, and he has been working in the field of fluid mechanics at the Sichuan Aeronautics and Space Administration."

"Both have more than ten years of working experience in fluid mechanics and modeling."

After briefly introducing Xu Chuan, Peng Hongxi turned to look at Zhou Ji and Xia Guang, and continued, "This is the general manager of our controllable nuclear fusion project, Academician Xu Chuan and Xu."

Hearing this, Zhou Ji stepped forward with a smile, and said, "Academician Xu is famous, I have heard about it for a long time, I have always wanted to meet, and today I finally got the chance."

On the side, Xia Guang's personality was a little more restrained, he just came up with a smile and shook hands to say hello.

Xu Chuan shook hands with the two with a smile, and said hello: "You have worked hard during this time, take me to see the optimized model."

Zhou Ji nodded and said, "Okay, let's find a conference room, it's not very good for demonstrations here."

In the meeting room, Xia Guang inserted the USB flash drive in his hand into the computer and connected it to the projection device.

Xu Chuan inspected the work they had done these days.

【Apply chain rule--optimize √】

[Neural network differentiation of space-time coordinates - optimization √]

[Multi-field turbulence model constraints--optimization √]

[Characterization of electric field fluctuations at the edge of turbulent flow--optimization √]

【.】

The item-by-item optimization catalog is presented in Xu Chuan's eyes, not only marking the completion of optimization, but also including the performance results tested after optimization and the comparison with the previous data.

Although the supercomputing center of Nantah University cannot fully run the entire mathematical model, it is not a problem to conduct individual optimization tests on certain modules in the model.

To be honest, it is quite difficult to optimize the test data of the numerical control model of plasma turbulence.

However, Zhou Ji and Xia Guang are indeed the top talents from the Chinese Academy of Sciences and the Space Administration, not only the areas that he marked that need to be optimized have been completed.

It is the places that he did not pay attention to and marked later, even if the performance can only be improved a little, he has also processed and rectified them.

After checking the relevant data, Xu Chuan nodded in satisfaction.

"From the data point of view, the optimization work is quite good. Give me a copy of the optimized model, and I will go to a supercomputer to verify it."

It has to be said that more people are more powerful.

If all these things were done by him alone, it would be impossible to finish them in less than half a year. This is still based on his familiarity with the model.

Taking the model with them, Xu Chuan and Peng Hongxi left the seventh floor.

Walking on the road, Peng Hongxi asked: "Your model should be just a phenomenological model right now? How are you going to solve the problem of precise detection of ultra-high temperature plasma in the chamber of a controllable nuclear fusion reactor?"

"If you can't accurately detect these plasma data, I'm afraid your model can't be used in the reactor."

The detection of ultra-high temperature plasma turbulence in the controllable nuclear fusion reactor is a major problem in the current controllable nuclear fusion technology.

Strictly speaking, it's really just one piece of the puzzle to control the 'ultra-high-temperature, high-pressure plasma turbulence' inside a fusion reactor chamber.

Controlling the plasma turbulence in a controlled fusion reactor is a crucial step on this path of controlled fusion research.

But it's not just one problem, it's a series of problems.

A series of issues such as the control of the strong magnetic field generated by the external superconducting coil, the establishment of a mathematical model to adjust the plasma turbulence, and the cooling system of the outer ring of the first wall are actually included.

It's just that at present, no matter whether it is inertial or magnetic confinement, or tokamak and stellarator, there is no way to solve this problem.

Hearing this question, Xu Chuan smiled and said, "This question is complicated, but it is difficult, maybe it is not difficult."

Hearing this, Peng Hongxi asked curiously, "How are you going to solve it?"

Currently, there are two common methods for measuring plasma turbulence in reactor chambers.

The first method is to measure the electromagnetic waves emitted by the plasma itself to obtain information about plasma parameters and so on. The second is probe measurement, which is one of the basic means of plasma diagnosis by putting a physical probe into the plasma to obtain the required parameters.

These two methods are the two most commonly used at present, but they all have their own defects.

The disadvantage of the first method is that the spectrum of electromagnetic waves emitted by ions is very wide, the information contained is quite messy, and the phenomenological model established can only be accurate within a limited range.

Although the second probe method can obtain information about the fine structure inside the plasma and the distribution of various parameters, the disadvantage is that it will interfere with the measured plasma.

For example, changing the flow image, forming a space charge sheath, generating impurity pollution, etc.

After all, the plasma in the fusion reactor chamber is operated at ultra-high temperature and ultra-high pressure, and any slight disturbance may cause the entire fluid operation to collapse. This in turn causes these plasmas to slam into the first wall violently.

Xu Chuan shook the hard drive in his hand with a smile, and said, "Actually, the answer to this question is already hidden in the mathematical model I built."

Hearing this, Peng Hongxi looked puzzled.

To be honest, he also knew about the model, but he didn't find anything hidden inside.

Xu Chuan smiled and said, "The mathematical model I have now is actually based on the data from the PPPL laboratory in Princeton."

"The biggest disadvantage of the phenomenology model is that it is not accurate enough, but the biggest advantage is that it is simple in logic and can be established in the absence of original data."

"And how the data of the PPPL plasma laboratory is observed, I think you should know."

Peng Hongxi thought for a while, and said: "If I remember correctly, the observation of high-temperature and high-pressure plasma by the PPPL Plasma Laboratory in Princeton uses the microwave detection method, which uses the principle of the interaction between microwaves and plasma in the electromagnetic spectrum to measure Plasma parameters."

"Are you going to use this method for measurement as well? But the data obtained by this method is also not accurate enough. Because the amount of information obtained is too large, it is difficult to analyze it accurately, and only a rough image can be obtained. data."

Xu Chuan smiled and said: "That's right, the data obtained from the detection of the deuterium-tritium plasma in the reactor chamber is indeed huge and difficult to analyze."

"But why do you have to look at the deuterium-tritium plasma itself?"

Hearing this, Peng Hongxi was taken aback for a moment, didn't he observe the plasma itself? What do you observe?

Xu Chuan smiled and said, "Observe the data of 'impurities'!"

After a pause, he continued to explain: "At present, the mainstream of our research on controllable nuclear fusion is DT controllable nuclear fusion. We are also taking this path now, and the raw material of DT fusion is deuterium and tritium. The fusion product It's a helium atom + a neutron."

"The neutrons will be reused for the tritium breeding reaction, and the helium atoms will be taken away by the divertor."

"In this case, why can't we add some helium atoms to the two raw materials, deuterium and tritium, as the original 'impurity'?"

"These helium impurities mixed into the raw material will run in the reactor chamber along with the deuterium-tritium raw material. Of course, it will finally enter the divertor and be sent away with the helium ash."

"But in operation, it produces electromagnetic radiation and microwave data that are quite different from deuterium-tritium plasmas."

"Compared with the information generated by the huge deuterium-tritium raw material itself, the amount of information generated by helium impurities is undoubtedly much smaller, but by observing the data of helium impurities, the plasma turbulence in the entire fusion reactor can be deduced. "

"In this way, the data we obtain is relatively accurate."

Xu Chuan explained, Peng Hongxi thought for a while, and suddenly understood, with a look of excitement in his eyes, he took the topic and continued:

"The most important thing is that helium itself is the product of deuterium-tritium fusion, and it will not participate in deuterium-tritium fusion, because if helium atoms are to be fused, the temperature must reach at least one billion degrees."

"In this way, it will not interfere with the fusion reaction of deuterium-tritium plasma, because the temperature of deuterium-tritium fusion cannot reach this height."

"And because it can monitor the movement of the entire plasma turbulence almost all the way along with the addition of fuel and the removal of the divertor."

"The only disadvantage is that it is very troublesome to accurately analyze the amount of information transmitted by these helium atoms. It is not like the information of deuterium-tritium plasma that can be processed by phenomenology."

"But it's not too difficult for you."

"Because you've solved the NS equations, the ability to even have a mathematical model of the plasma turbulence in the reactor chamber for predictive control."

"As for the amount of calculation, it is a matter of supercomputing. As long as the performance of supercomputing is sufficient, then these troubles can be solved!"

After talking to himself, Peng Hongxi raised his head and looked at Xu Chuan, his eyes sparkling with excitement.

To be honest, it is not the first time that it is proposed to collect the electromagnetic waves of impurities by adding impurities in deuterium-tritium fuel to accurately judge the state of plasma turbulence.

But before, no one could do it.

Without him, because it can't be calculated at all.

Even if someone can make a mathematical model of it, it is impossible to control the movement of plasma turbulence for a long time.

Because the fluid system is chaotic and extremely sensitive to the initial value, you cannot give an accurate initial value for the flow in reality, and small disturbances are inevitable, and these will be amplified to produce unpredictable results.

In the past, the motion of plasma turbulence can be said to be a completely chaotic system, and no one knows how it will evolve over time.

The reason why it is feasible now is because the person in front of him has already settled the theoretical basis.

He solved the NS equation, and used the result to make a mathematical model in a targeted manner. With this foundation, the calculation can be completed by this method.

This is the advantage of theory first.

This top-level cutting-edge theoretical breakthrough and the technological development driven by it can be described as vividly reflected at this moment.

More importantly, this is only a part, and it can even be said to be a drop in the bucket. More advances in the field of fluid mechanics will appear over time.

Various fields related to fluid mechanics, including aerospace, aerodynamics, weapon equipment, etc., will usher in a leap forward with the deciphering of NS equations.

Just like the one who made the country hold the sword tightly, this one also has the ability to drive a field or even a country forward.

After staring at Xu Chuan for a while, Peng Hongxi suddenly sighed softly: "How lucky is the country to have you!"