Chapter 401 The Finishing Touch!

A year later, on the third day of the first lunar month, Xu Chuan returned to the Qixia Controlled Nuclear Fusion Engineering Base.

The problem of magnetic surface tearing during the fusion of deuterium and tritium raw materials and the selection of the first wall material, the two biggest problems in the deuterium and tritium fusion ignition experimental stage, have been revealed and thought.

As soon as this is resolved, the construction of the demonstration reactor can begin.

Striking while the iron is hot, without knowing the progress of controllable nuclear fusion in Western countries, all he can do is try to speed up his own pace.

In the third year of junior high school, it was not only him who returned to work, but also Zhao Guanggui's team who developed the first-wall carbon composite materials, as well as the researchers and engineers who came back after the annual vacation.

Qixia Institute of Controlled Nuclear Fusion Engineering, Computational Materials Research Laboratory.

Xu Chuan found Zhao Guanggui, who was leading a team that was working hard to develop new carbon composite materials.

"How is the situation?" After finding Zhao Guanggui, Xu Chuan asked.

Naturally, he was asking about the development of new carbon composite materials made using zirconium oxide instead of hafnium oxide as a catalyst. After all, this is the key to hopefully solving the first wall problem.

Zhao Guanggui shook his head and said: "It's not ideal. Although the chemical properties of hafnium oxide and zirconium oxide are very similar, they are not the same substance after all."

"On the last day of the year, although we successfully produced a carbon composite material using zirconia as a catalyst, the test results were not very good."

"Whether it is in terms of high temperature resistance or radiation resistance, it is inferior to carbon composite materials made using hafnium oxide as a catalyst, and the parameters cannot meet the requirements of the first wall."

Xu Chuan asked: "Does the problem occur in that special and unique arrangement of carbon nanotubes and hafnium crystal structures?"

Zhao Guanggui nodded and sighed: "Well, after using zirconium oxide instead of hafnium oxide as the catalyst, although carbon composite materials can also be produced, the uniquely ordered carbon nanotube-hafnium crystal structure has not appeared."

"Your previous speculation is correct. From this point of view, that special crystal structure is the key to greatly improving the high temperature resistance and radiation resistance of hafnium oxide carbon composite materials."

After thinking for a moment, Xu Chuan said, "Take me to see the experimental data."

"Okay." Zhao Guanggui nodded, took Xu Chuan to another laboratory, and turned on a computer.

On the display screen, a piece of data was called up.

Zhao Guanggui stepped aside and said respectfully: "This is the test data. Time is tight. There are still some radiation resistance tests that have not been completed. It is estimated that it will take about three days to obtain complete data."

Xu Chuan didn't care and said, "It's okay, I'll take a look first."

Sometimes, understanding the properties of a material does not necessarily require all the test data.

Compared with other things, he only needs to look at the scanning electron microscope imaging images and related data of this new material.

Zirconia fails to hook up with carbon atoms as expected, and the formation of a specially ordered carbon nanotube-hafnium crystal structure is the main reason for the failure of material development.

If you can find this reason and solve it, that's almost it.

Putting his palm on the mouse, Xu Chuan swiped the information and his eyes fell on the scanning electron microscope test results.

Judging from the imaging images, the carbon composite materials produced by using zirconium oxide instead of hafnium oxide as the catalyst and enhancer do not have the specially ordered carbon nanotube-hafnium crystal structure.

The carbon nanotubes in the material are piled up in a disorderly manner. From the crystal structure, they are no different from ordinary sheets formed by pressing carbon nanotube powder.

In other words, zirconium oxide does not play a catalytic role in the material and does not eutecticize with the carbon nanotube material to form carbon nanotube zirconium crystals.

While looking through the test data, Xu Chuan asked Zhao Guanggui beside him: "Have you ever speculated on the cause?"

Zhao Guanggui said with a wry smile: "Yes, there is, but we can't analyze any results in a short period of time."

"Theoretically, zirconium and hafnium are both lanthanide shrinkage elements with very similar chemical properties and the same outer electron arrangement. There should not be a situation where hafnium can form a crystal structure but zirconium cannot."

It is difficult to analyze a material and understand its formation reasons and processes from the perspectives of physics, chemistry, and materials science.

What's more, they don't even know why hafnium oxide acts as a catalyst to form a unique carbon nanotube-hafnium crystal structure in carbon composite materials.

In this case, it is too difficult to find out why zirconium oxide cannot be used as a catalyst to symbiotically produce a carbon nanotube-zirconium crystal structure.

Xu Chuan touched his chin and said, "Send this test data to me, and I'll go back and take a look first."

His attainments in materials are not comparable to ordinary materials researchers like Zhao Guanggui. Theoretically, it is no problem for zirconium to replace hafnium and symbiosis with carbon nanotubes to form a unique crystal structure.

But now that there is a problem, it means there is a problem there.

He planned to go back with these data to study and see if he could find the problem through calculation of material mathematics.

Although the Chuanhai Institute of Materials has a material calculation model, the model is ultimately dead and incomplete and cannot take into account all aspects.

So he was going to study it himself.

With the data in hand, Xu Chuan returned to the office.

For him, mathematics is not only an independent subject, but also a powerful scientific research tool that assists other subjects.

Although many times, especially in materials science, the results obtained through mathematical calculations cannot directly provide answers, the relevant analysis can serve as a reference and help him avoid many detours when developing new materials.

Especially now, he does not need to analyze it from beginning to end, it is enough to only deal with specific links.

Staring at the data and pictures on the computer, Xu Chuan fell into deep thought.

Although computational materials are his area of ​​expertise, it is still quite difficult to pinpoint the problem of zirconia’s inability to coexist with carbon nanotubes.

After thinking for a while, he picked up the ballpoint pen from the table

[GPAW pseudopotential: 1s22s22p6Zr3s23p64s23d104p65s24d2]

[e convergence: Ve=∫dru(R)ψ+0.05eV/(R)ψ(R)AB]

[eV particle convergence: p(R)=<Φ|ψ+(R)ψ(R)|Φ10-6eV]

For computational materials science, if we want to achieve chemical accuracy through electronic scale calculation methods, they are generally based on wave functions.

However, due to computational constraints, any non-bulk material properties such as interfaces must be carried out using alternative methods, such as constructing a thermodynamic phase diagram. Considering the extremely complex potential energy surface, the dynamics is basically unsolvable.

In Xu Chuan's view, the new field of computational materials is actually very interesting.

Whether it is combined with test data, by establishing a mathematical model and then through numerical calculation, the simulation reproduces the actual process;

Or through computational simulation, we can predict, design or modify the material structure and performance directly through theoretical models and numerical calculations for specific materials, specific physical mechanisms or reaction mechanisms.

These are all areas with very broad prospects.

However, it is still an area waiting to be explored by the scientific community.

As the days progressed like this, Xu Chuan locked himself in the office and used mathematical tools to theoretically improve the symbiosis of zirconium oxide additives, while Zhao Guanggui continued to conduct experiments.

Others are also busy at their jobs in an orderly manner.

Time passed by on the twelfth day of the first lunar month. On the last day of the twelfth day of the year, Xu Chuan finally completed the last step of calculation.

Looking at the calculations filling the computer screen, a smile gradually appeared on his lips.

What was the problem? Through calculation, he found it!

After checking the data and confirming that there were no problems, he reached for the phone. Just as he was about to call Zhao Guanggui and ask him to come over, Zhao Guanggui appeared in the office.

"Academician Xu, the neutron irradiation test results of the carbon composite material synthesized using hafnium oxide as a catalyst in Daya Bay have come out."

With a stack of information, Zhao Guanggui walked up to Xu Chuan and reported the neutron irradiation results of hafnium oxide carbon composite materials.

Xu Chuan asked with a smile: "What was the result?"

Zhao Guanggui sighed and said: "It's very bad. The low-energy neutron beam causes high damage to the sample material. At the 3MeV level neutron energy level, at a distance of 1.5 μm, the dpa reaches 3.01, which is lower than Austrian steel. "

"In the test temperature range from room temperature to 300°C, the section shrinkage after irradiation is 73% to 80%."

DPA is a method to measure the degree of radiation damage to a material. It represents the ratio of the number of times atoms on the crystal lattice are bombarded from their original positions by particles to the number of atoms on the crystal lattice.

3.01dpa means that each atom in the material is moved from its original position an average of 3.01 times.

It may not sound like much, but for the first wall material, this is already quite high data, not to mention that in subsequent cross-section tests, the shrinkage rate reached more than 70%.

These data all mean that after the carbon nanotube hafnium crystal structure is damaged by neutron irradiation, the performance of the carbon composite material is drastically reduced.

Hearing the news, Xu Chuan was not too surprised.

Years ago, he made speculation through his own simulation calculations and determined that hafnium oxide carbon composite materials were probably not feasible.

Now the results came out, just as he had expected.

Smiling, Xu Chuan said, "How is the research on zirconia carbon composite materials going?"

Zhao Guanggui shook his head and sighed: "There hasn't been much progress yet, so I'm disappointed."

Xu Chuan smiled, clicked twice on the mouse with his right hand, then stood up and walked to the printer.

After waiting for a while, the file from the printer was output. He picked up the information, handed it over, and said with a smile: "It doesn't matter, don't feel any pressure. This is a difficult job in itself, and there is no such thing as a short time." The progress is normal.”

"Look at this first."

Zhao Guanggui took the printing paper with some doubts and looked at it.

After seeing what was above clearly, his pupils shrank sharply.

"You found the problem?!"

Looking at the calculations and conclusions on the document, Zhao Guanggui couldn't suppress the shock in his heart and blurted out a question.

Xu Chuan smiled and nodded, saying: "Theoretically, yes, but the details will depend on the experimental conditions."

After a pause, he continued: "The specific experiments will be left to you. If possible, I hope you can lead someone to make these materials within five days, and then complete the test within a week."

"Because the slow neutron irradiation experiment at Daya Bay starts every month, today is the 14th of the solar calendar. If we miss it, we have to wait for another round, which will take too long."

The inspection of the first wall material is actually a very troublesome thing.

First of all, the ordinary physical properties, such as thermal conductivity, high temperature resistance, radiation resistance, etc., can be done in Qixia.

After confirming that these basic properties have passed, the material will be sent to Daya Bay for slow neutron irradiation testing.

If the slow neutron irradiation test results at Daya Bay are good, he will consider conducting a real deuterium-tritium fusion high-energy neutron irradiation test on it in the Dawn Fusion Device.

After all, under the current situation, every time Dawn conducts a real deuterium-tritium fusion ignition operation, it will cause some irreversible damage to the device.

To repair these damages, it will take a lot of manpower, material resources and funds every time, and it will take at least half a month. If it is longer, it may take a month.

Every time the Dawn Fusion Device is shut down for maintenance, it is prolonging the battle line of the "Controlled Nuclear Fusion Competition".

Hearing this, Zhao Guanggui straightened his body, and replied with a serious face, almost saluting: "Don't worry, I will do my best!"

Xu Chuan smiled and nodded, saying: "Okay, I'll leave it to you."

The computational materials laboratory is very efficient.

In other words, after Xu Chuan found out why zirconium oxide cannot form a carbon nanotube·hafnium crystal structure like hafnium oxide, the experiment progressed quite smoothly.

With Zhao Guanggui and his team sleeping on the floor and sleeping on recliners in the laboratory for 24 hours, in just three days, the first batch of carbon composite materials samples made with zirconium oxide as a catalyst were successfully manufactured.

The materials were sent to different equipment one by one, and various tests were carried out quickly. When the data from the scanning electron microscope appeared, Zhao Guanggui found Xu Chuan at the first time, with a look of excitement and excitement on his face.

"Professor, the SEM data of the new material is out!"

"Carbon nanotubes and zirconium atoms, similar crystal structures, have been formed!"

"We have hope!"

Panting, Zhao Guanggui, who ran all the way, used several sentences intermittently, and finished his expression incoherently.

Xu Chuan stood up and took the test data from him.

On the SEM image, the special crystal structure of zirconium and carbon nanotubes was extremely conspicuous.

As for some other test data, although many values ​​have some errors and discrepancies with the results simulated by him through computational materials science methods, such as the high temperature resistance range is reduced to 3,100 degrees, which is nearly 400 degrees lower than the carbon composite material catalyzed by hafnium oxide.

But the high temperature resistance of 3,100 degrees is enough for the first wall material.

As far as the test results are concerned, these samples are basically consistent with his previous calculation results.

Now, the final touch is missing!

Theoretically, the carbon composite material using zirconium instead of hafnium as a catalyst can fully meet the performance of neutron radiation resistance.

Of course, the specific situation depends on the experimental results.

But at least, his calculations have never been wrong!

This time, there is great hope!

After reading the test data in his hand, Xu Chuan smiled and praised: "Not bad, thank you for your hard work. I will arrange for someone to rush the materials to Daya Bay for the first round of slow neutron irradiation experiments."

"As for now."

After a pause, his eyes fell on Zhao Guanggui, who had dark circles under his eyes and was a little unsteady on his feet, and then said: "Thank you for your hard work. Go back and rest early. The rest of the work can be done slowly."

It must be said that more than half of the members of the Materials Research Laboratory are middle-aged professors in their forties like Zhao Guanggui.

They are in the prime of their lives, energetic and experienced.

But no matter how prime they are, they are lucky not to collapse in the laboratory after staying up late for ten days and a half months.