Great Country Academician

A letter sent from Jinling to the capital touched the hearts of many people this early autumn.

However, the author of the letter did not pay attention to this at the moment.

The development of chips is indeed important, but that is not his area of ​​research.

He can do some basic theoretical work and even conduct further research on basic materials for carbon-based chips or quantum chips, but the core of the chip process is still processing.

Ultra-high-precision processing at the nanometer level, whether it is photolithography machines, photoresists or EDA software, is not within the scope of his research.

Therefore, even though he had done some theoretical research on quantum computers, Xu Chuan did not rush into this unfamiliar field.

And he now has a lot of work on hand, and there is no time left for him to study chips.

Whether it is the miniaturized controllable nuclear fusion technology or the aerospace engine that is already on the right track, or the construction of the large strong particle collider that is just about to start up, he needs to invest time and energy to deal with related work.

At the end of August and the beginning of September, the 2022 school year ushered in a group of new students.

On the NTU campus, people come and go.

Groups of young faces stepped into the campus with hope in their eyes, and they also held high expectations for university life and the future.

In the orientation venue, sitting under a temporary awning, the major departments responsible for receiving new undergraduates were busy handling the reception work in an orderly manner, while chatting and boasting.

"I heard that the admission score of our mathematics department has been raised to what extent this year?"

Seeing the freshmen carrying bags following the footsteps of their seniors towards the School of Mathematics, a junior undergraduate from the Department of Applied Mathematics asked boredly.

On the side, a sophomore who was standing next to him after receiving a new student nodded and said with a smile: "Although the admission scores are different in different provinces, overall they are almost 20 points higher than last year."

After a pause, he added: "Especially for the Mathematics and Applied Mathematics major taught by Academician Xu, this year's score has been raised to 700 points, which is ten points higher than the Mathematics Department of Peking University."

"Awesome! Single-handedly driving the development of the entire math college, PKing Peking University, tsk tsk, that's awesome." The junior shook his head and sighed.

"Aren't you talking nonsense? A Novel double prize winner and the number one person in mathematics. Does Peking University have it? Peking University doesn't have anything."

The student who just entered the sophomore year smiled and compared it, and then said: "Speaking of which, his students have all won the Fields Medal. It is estimated that many freshmen in this class are here for that big shot. of."

"It's just a pity that he has too few classes. Every class is like a war. He can't get a seat."

Speaking of this, the junior students around me complained: "I am speechless when I talk about this. It's okay for undergraduates to compete for seats. Those postgraduate and doctoral students will come over to compete for seats as soon as they hear that he has started classes. What are they doing? Hey, they’re also coming to grab university courses!”

"However, Academician Xu's lectures are really good. There are many issues that other professors explain in a complete mess, but he can explain them clearly to you in just a few sentences."

On the side, a sophomore student said with a smile: "When it comes to grabbing classes, that's not all. Not to mention those from our school, there are people from Hehai, Dongda, and Southeast who take the subway to come here."

"As for speaking well, isn't that normal? You have to be competent and good-looking, and you have to be handsome."

When freshmen were admitted in the fall, Xu Chuan was also arranging and preparing for his teaching work in the second half of the year in the office of the teaching building.

Although this is not a big deal to him, and just talking about it can benefit those newbies a lot, he has never despised this work because of its simplicity.

Not only because of the inheritance of knowledge, but also because in the teaching process, he can reorganize the knowledge he has learned and researched from the most basic areas.

He enjoyed the process and was happy to do it.

"Algebraic geometry, topology, differential equations, functions."

After writing down a few general directions in the planning book, Xu Chuan thought about it and added number theory to it.

Although his research direction and focus are not in the field of number theory, there is a conjecture in the field of number theory that he cannot ignore.

The importance of the Riemann Hypothesis is not only due to the thousands of propositions and papers related to it, but also because it is an important bridge between unifying algebra and geometry.

In addition, at the International Congress of Mathematicians, he also discovered something more interesting.

That is, the correlation function caused by the Riemann hypothesis can correspond to the pair correlation function of the eigenvalues ​​of the random Hermitian matrix.

Prime numbers may be connected to time and space, which is something Xu Chuan has never thought of before.

Perhaps in the simplest and most primitive realm of pure mathematics, the deepest mysteries of the universe are hidden.

This is not impossible.

Such as calculus.

The birth of calculus ushered in the grand era of Newton's mechanical cosmology. People were surprised to find that there was nothing in the world but the king's land. The physical world is neither mysterious nor different. Even the laws of motion of celestial bodies hidden in the deep space of the universe are subject to the laws established by humans.

Or the general theory of relativity, which is based on the application of non-Euclidean geometry (especially Riemannian geometry) and tensor analysis, has completed the establishment of the space-time view of the entire universe.

It is not impossible for mathematical theory to be translated into reality and become the most powerful tool, fueling the development of modern science and technology and the development of other fields.

Up to now, all major branches of mathematics are quietly providing exquisite applications for cutting-edge science.

Mathematics research, which was once shelved and kept in a corner, is becoming a sharp weapon in people's hands, overcoming obstacles on the way to explore the material world, and providing people with more and more sources of ideological motivation and creation.

Unfortunately, there is a branch that has accompanied mankind on the arduous journey of truth exploration for more than two thousand years, but it is still admiring itself in its closed theoretical kingdom.

It is the oldest and most loyal partner of mathematicians, the ‘number theory’ that never abandons it.

This largest branch of mathematics has accumulated countless profound theoretical achievements, but today's science and technology can benefit from very few achievements in number theory. It is not an exaggeration to say that it is the tip of the iceberg hidden underwater.

Perhaps one day, when the iceberg melts, the fruits of number theory can benefit every future generation.

And this hope of breaking the ice is probably the Riemann Hypothesis at the top of the mountains.

This is also the reason why Xu Chuan added number theory to his daily teaching.

In the process of researching "space and time", he increasingly felt that one of the biggest mysteries of space and time in the universe might be hidden in the purest mathematics.

After making a simple plan for the teaching work in the new semester, Xu Chuan stood up, rubbed his eyes, stretched, and shouted toward the door.

Outside the door, Tang Ran, who was doing his own work, quickly came over. Xu Chuan handed over the course plan in his hand and said, "This is the plan for the second half of this year. You can make a simple arrangement and report it to the Academic Affairs Office." .”

Tang Ran took the paper, glanced at it, nodded, and said, "Okay, Professor. Is there anything else?"

Xu Chuan thought for a moment and said: "Help me collect papers related to number theory in the four major mathematics journals, mainly in three aspects: analytic number theory, algebraic number theory and geometric number theory."

Tang Ran: "No problem, I'll arrange someone to do it here. Is there any other work?"

"No, let's go."

After handing over the work in his hands to his assistant, Xu Chuan sat down again and continued to sort out the work in his hands.

At this moment, the mobile phone on the desk vibrated.

He casually touched his cell phone from the table and glanced at the incoming call notification. It was Liang Qu from Xinghai Research Institute and Energy Research Institute. Xu Chuan did not hesitate. He lightly slid his finger on the screen and answered the call. .

"Hello?"

"professor.!!!"

On the phone, Liang Qu's voice had some uneasy trembling, and he didn't say a word for a while.

Sensing something was wrong, Xu Chuan immediately asked without thinking, "What's wrong? What happened?"

On the other side of the phone, Liang Qu took a deep breath, swallowed the air hard and said, "Professor, regarding the miniaturization of the stellarator, we may be able to do it!"

Hearing these words, Xu Chuan was also stunned.

There was silence on both ends of the phone for a while before he came back to his senses.

Taking a deep breath, Xu Chuan quickly said: "I'll go over right away and we'll talk about it later."

As soon as he finished speaking, he hung up the call, found Zheng Hai's phone number, and dialed it.

"Wait for me downstairs in my office as quickly as possible."

On the opposite side, Zheng Hai felt something was wrong in the voice and quickly replied: "I'll be right over."

"Go to Xinghai Research Institute."

Downstairs, a black Hongqi car drove over. As soon as the car stopped, Xu Chuan opened the door and got in.

"good."

Zheng Hai nodded, started the car and drove towards Qixia Mountain. The drive of less than half an hour passed quickly, and the vehicle stopped steadily at the entrance of the institute.

After getting out of the car, Xu Chuan walked straight into the building and towards the core laboratory without stopping.

In the core laboratory, researchers in white coats were still busy at their jobs, but the atmosphere in the entire laboratory was extremely exciting, with bright smiles on everyone's faces.

On the huge data monitoring screen, the Huaxing Fusion Device, which has completed a complete operation, is slowly shutting down. The high-temperature plasma in the chamber is gradually dissipating, and the temperature has also cooled down.

"what's the situation?"

After quickly walking into the laboratory and glancing at the data on the monitor, Xu Chuan quickly found Liang Qu who was full of excitement and asked.

"We did it! We did it!"

Liang Qu responded excitedly, with trembling and excitement in his voice: "Using the idea of ​​the permanent magnet stellarator that you proposed before, and under the influence of nonlinear optimization algorithms, through supercomputing we can calculate the external field coil and The parameters of the magnet set were simulated and adjusted to optimize the predetermined objective function as closely as possible.”

"Then we used the analytical model and the simple elliptical stellarator to complete the verification of the FOCUS program, confirm and debug the modular coils of the improved stellarator from different angles, and repair the error field generated by the permanent magnet spiral coil."

A series of explanations came out of Liang Qu's mouth quickly. Perhaps because he was too excited, the explanations at this time were a bit confusing. Fortunately, this was the most familiar field, and Xu Chuan could barely understand the other party's method.

However, for further confirmation, he asked Liang Qu for a planning document and read it carefully.

He was more interested in how they did it than in the success itself.

As mentioned before, the overly complex coil system of the stellarator is a serious challenge restricting its development.

The complex structure will aggravate the loss and loss rate of high-temperature plasma inside the reactor chamber, causing serious neoclassical transport problems.

This is not only a problem for the stellarator to achieve controllable nuclear fusion technology, but also a major problem on the miniaturization route.

In order to find a suitable three-dimensional coil to achieve a carefully optimized plasma configuration, he previously built a permanent magnet stellarator. Experiments proved that this idea is effective. In subsequent fusion research, the Huaxing fusion device successfully reduced New classic transport and complete a simulated power generation.

But this is not enough, because as the size of the reactor shrinks, the neoclassical transport will increase, and they need to further find ways to reduce the loss of high-energy particles.

Quickly flipping through the documents in his hand, Xu Chuan had a look of surprise on his face, understanding what they were doing.

Based on the permanent magnet stellarator, the Energy Research Institute uses supercomputing to calculate the required magnetic field perturbation using the magnetohydrodynamics (MHD) perturbation balance program GPEC based on the physical properties of the plasma that need to be controlled, and then uses FOCUS Go straight to the search for a suitable RMP coil that produces the desired magnetic perturbation.

By using the gradient of the objective function and the Hessian matrix to guide the optimization process, the optimization speed and convergence performance of this approach are significantly improved.

In addition, they also designed a set of quasi-symmetrical configuration coils inside the magnet winding of the stellarator through the R.MP coil design method.

This can further enhance the advantages of the permanent magnet stellarator, improve the sensitivity analysis of the error field caused by the plasma deflection inside the chamber, achieve rapid and concise positioning, and then adjust it through the magnetic field.

I have to say, this is an ingenious method.

It perfectly cooperates with the modified modular permanent magnet unit of the permanent magnet stellarator to achieve local fine-tuning of the magnetic field inside the reactor chamber, which can keep the high-temperature plasma in the chamber on a stable line and avoid them Large losses in the banana zone and collision zone reduce the new classic transport of the stellarator.

In this way, the size of the permanent magnet stellarator can theoretically be further reduced!