Chapter 337 The Country Is so Lucky to Have You

Xianlin Campus, in the industrial building.

The second time he came here, this time Xu Chuan specifically observed the office conditions in the building.

Two months have passed, and under the leadership of Academician Peng Hongxi, staff recruitment and project research have been fully launched.

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

Of course, he didn't take a closer look.

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

As for those other issues, someone still has to do it.

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

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

Inside, Peng Hongxi was sitting at his desk, handling work. He raised his head when he heard the knock on the door, 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 both academies in one day."

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

Peng Hongxi said with a smile: "Those who know first come first. Your knowledge and ability are far beyond those of us old men."

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

"What about the previous plasma turbulence control model? Take me to see it. If there are no problems, I have to apply for a supercomputer to verify it. There are still a lot of things to do in the future."

Peng Hongxi nodded, stood up and said, "Follow me. The model optimization is almost done, but I don't know if it has met your requirements."

Xu Chuan: "Let's take a look first. If it doesn't work, we can change it later."

"For controllable nuclear fusion, the control of plasma turbulence in the chamber is a major matter. There is no need to rush, and everything must be ensured."

Following Peng Hongxi, the two of them reached the seventh floor.

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

Peng Hongxi shouted to the people in the office who were busy in front of the computers, and soon two middle-aged men stood up and walked over quickly.

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

"In the past two months, they have been working with plasma professors to optimize the model."

"Zhou Ji and Xia Guanghe are the two people currently in charge. They are upright and correct."

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

"Xia Guangze graduated from Hua Science and Technology University and had been working in fluid mechanics at the Sichuan Aeronautics and Space Administration."

"Both of them 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 then said: "This is the general person in charge of our controllable nuclear fusion project, Academician Xu Chuanxu."

Hearing this, Zhou Ji stepped forward with a smile and said, "I have heard of Academician Xu's fame for a long time and have always wanted to meet him. Today I finally got the chance."

On the side, Xia Guang's character was a little more reserved. He just smiled and came up to shake hands and say hello.

Xu Chuan smiled, shook hands with the two of them, and said hello: "Thank you for your hard work during this period. Please take me to see the optimized model."

Zhou Ji nodded and said, "Okay, let's find a conference room. It's not easy to demonstrate here."

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

Xu Chuan was testing the work they had completed these days.

[Application of chain rules--Optimization√]

[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√]

【.】

An item-by-item optimization catalog appeared in Xu Chuan's eyes, which not only marked the completion of optimization, but also included the performance effects tested after optimization and comparison with previous data.

Although NTU's supercomputing center cannot completely run the entire mathematical model, there is still no problem in conducting individual optimization tests on certain modules in the model.

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

However, Zhou Ji and Xia Guang are worthy of being top talents from the Chinese Academy of Sciences and the Space Administration. Not only have they completed all the areas that he marked that need optimization.

It was the areas that he didn't pay attention to and mark out later, even if it could only improve the performance a little, he still dealt with and rectified them.

After testing the relevant data, Xu Chuan nodded with satisfaction.

"Judging from the data, the optimization work has been done quite well. Give me a copy of the optimized model, and I will go find a supercomputer to verify it."

It has to be said that more people means more power.

If he were to do all these things by himself, he wouldn't be able to finish them in more 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 is probably just a phenomenological model at present, right? How do you plan to solve the problem of accurate detection of ultra-high temperature plasma in the controllable nuclear fusion reactor chamber?"

"If you can't accurately detect the data of these plasmas, I'm afraid your model won't be able to be used in reactors."

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

Strictly speaking, it is actually just part of the problem of controlling ultra-high temperature and high pressure plasma turbulence in the fusion reactor chamber.

On this path of controllable nuclear fusion research, controlling plasma turbulence in controllable nuclear fusion reactors is a crucial step.

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.

But at present, no one path can solve this problem, whether it is inertial constraint, magnetic constraint, or tokamak and stellarator.

Hearing this question, Xu Chuan smiled and said: "This question can be said to be complicated or complicated, but if it is said to be difficult, it may not be 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 the reactor chamber.

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

These two methods are currently the two most commonly used, but they both have their own shortcomings.

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

Although the second probe method can obtain information about the detailed structure inside the plasma and the distribution of various parameters, its 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 operates at ultra-high temperature and ultra-high pressure, and any slight disturbance may cause the collapse of the entire fluid operation. This in turn causes these ions to violently crash into the first wall.

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

Hearing this, Peng Hongxi looked confused.

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

Xu Chuan smiled and said: "The mathematical model I have at hand is actually based on the previous data from the Princeton PPPL Laboratory."

"The biggest shortcoming of the phenomenological model is that it is not accurate enough, but the biggest advantage is that the logic is simple and it can be established when the original data is scarce."

"I think you should know how the data from the PPPL Plasma Laboratory was observed."

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

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

Xu Chuan smiled and said: "Yes, the data obtained by detecting deuterium and tritium plasma in the reactor chamber is indeed huge and difficult to analyze."

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

Hearing this, Peng Hongxi was stunned for a moment. Didn't he observe the plasma itself? What to observe?

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

After a pause, he continued to explain: "Currently, the mainstream of the controllable nuclear fusion we are studying is DT controlled nuclear fusion. We are also taking this path now. The raw material for DT fusion is deuterium and tritium, the product of fusion. It’s helium atoms + neutrons.”

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

"In this case, why can't we mix some helium atoms into the two raw materials deuterium and tritium as original 'impurities'?"

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

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

"Compared with the information generated by the huge deuterium and tritium raw materials themselves, 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 will be relatively accurate."

Xu Chuan explained. Peng Hongxi thought for a moment and suddenly understood. With a hint of excitement in his eyes, he took over the topic and continued:

"The most important thing is that helium itself is a product of deuterium-tritium fusion and 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 is accompanied by the addition of fuel and the removal of the divertor, it can almost monitor the movement of the entire plasma turbulence throughout the process."

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

"But for you, this is not a difficult task."

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

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

After muttering 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 the state of plasma turbulence can be accurately judged by adding impurities to deuterium-tritium fuel to collect electromagnetic waves of impurities.

But in the past, no one could do it.

There is no other reason, because it cannot be calculated at all.

Even if someone can make a mathematical model for 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 initial values, you cannot give accurate initial values ​​for the flow in reality, and small disturbances are inevitable, which will be amplified, resulting in unpredictable results.

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

The reason why it is feasible now is that the person in front of you has already figured out the theoretical foundation.

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

This is the benefit of theory first.

This kind of top-level frontier theoretical breakthrough has driven the development of science and technology, which is vividly reflected at this moment.

More importantly, this is only a part, or even a drop in the bucket. More progress in the field of fluid mechanics will appear over time.

Various fields involving fluid mechanics, including aerospace, pneumatics, weapons and equipment, will usher in a leap forward with the deciphering of the NS equation.

Just like the one who made the country hold the sword tightly in his hand, 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: "The country is so lucky to have you!"