Scholar’s Advanced Technological System

With that sketch, Chief Engineer Wang left the STAR Astronomy Institute and returned the same day to the Nuclear Industry Group headquarters in Shangjing, where he contacted experts working in the direction of magnetic fluid power generation at the Engineering Institute to discuss the feasibility of applying magnetic fluid power generation technology to controllable fusion devices.

However, despite the departure of the team, the Nuclear Industry Group's working group remained on the side of Jinling and was in constant communication with researchers at the STAR Institute of Mirrors on technical issues.

Meanwhile, the experiments with the STAR device have not stopped.

With adequate funding guarantees, the Institute was almost luxurious enough to conduct experiments every three days to observe the complex physical properties of plasma in star imitators, with hydrogen and helium being the subject of separate studies.

Even, in order to collect valuable data, the Ark even ordered the injection of 1 mg of precious deuterium mixture into the reaction chamber and conducted a pilot ignition at risk of damaging the first wall material.

In fact, the experiment did cause some damage to the STAR unit, but it is good that the damage is still within repairable range. Even so, however, the entire unit must not be suspended for one month.

Of course, although it is costly, the returns are also quite substantial.

Not only did they test the feasibility of fusion reaction ignition with this technical approach, but they also obtained a lithium sheet that had been bombarded by a beam of neutrons carrying 14 MeV of energy.

Especially the latter, whose scientific value cannot be translated with money.

They're probably the only ones in the country that can do this kind of luxury experiment.

At this moment, this hard-won lithium metal sheet is lying quietly in specially treated anaerobic glass, viewed under a scanning electroscope by staff in protective clothing.

In the lab outside the quarantine room, researchers, such as the Ark in front of the computer, saw data and pictures taken from the scanning mirror on the screen.

As they had expected, the original metal surface was now 100 holes of sores.

Through infrared spectrometer detection, traces of residual helium and tritium elements can even be observed in that curved pore.

Happily, this suggests that the beam of neutrons carrying 14MeV of energy did react with 63Li, who successfully recovered some of the tritium elements in the experiment.

As for the helpless...

They faced too many problems, and the three words and two words were simply incomplete.

Looking at the images on the computer screen, Professor Li Changxia sighed lightly.

“I bet this thing breaks when you touch it gently. ”

“Without a bet, even if it hadn't been bombarded by a bunch of neutrons, it wouldn't talk about how sturdy it is.” Staring at the hard-won data on the computer screen, the ark said casually.

Sheng Xianfu shook his head: “It's not just about radiation damage, but the tritium growth ratio is really too low. And the most critical issue is not recycling itself. Neutron bundles carry too much energy, often not reacting with the 63Li on the surface, but running around inside the cladding material, leaving even the tritium that we need inside the material, and simply not releasing it. ”

A neutron carrying 14MEV energy is like a shell, and in front of it all the metal bonds are as tough as toys.

Moreover, the neutron penetrating the first wall is not only as simple as punching a hole in the first wall, it creates a cavity inside the first wall material like a blowing balloon, eventually causing swelling, brittling, and even the surface material to fall off of the first wall material as a whole, causing serious accidents.

This is also one of the main reasons why the fission reactor cladding material cannot be obtained directly from the fusion reactor.

Both materials are exactly two orders of magnitude short of radiation damage standards.

So far, their research has entered an unknown realm, which also means that there is no longer any experience of the former. What to do next and how to solve these problems all depends on their own thinking.

After a moment of reflection, Professor Li Changxia tried to suggest, "How about using molybdenum instead of structural materials? ”

“Molybdenum doesn't work," he dismissed instantly, the canoe shook its head, "Molybdenum has good heat resistance, but becomes radioactive under neutron irradiation. ”

Another researcher went on to suggest, "Where's tungsten? The heat resistance of tungsten is good, the transformation product is hafnium, there is no radioactivity problem! ”

No more ark talk this time, Professor Li Changxia shook his head, “Old life talking about the question. The heat resistance of tungsten is fine, but the plasticity is poor. Thermal stress can lead to cracking of the surface of the material… When I was studying at the DIII-D lab, there was a report topic dedicated to this issue. In short, it is impossible to use tungsten. ”

The lab was silenced again.

At this point, he kept staring at the ark of the data on the screen and suddenly opened his mouth.

“If we can't get the neutron bundles in, why don't we consider putting them in there? ”

“Put it there?” Sheng Xianfu shook his head with a smile. “How else do we recover the neutrons from the reaction? ”

Neutrons produced in the recovery of DT fusion reactions are a key part of the overall nuclear fusion reactor technology. After all, tritium resources are more than tens of thousands of times more expensive than deuterium, and the cost of a gram is as high as $30,000 (17 years data).

Failure to recover the neutrons generated by the reaction will not only result in significant energy losses, but will also result in reactor "shutdown” due to the loss of tritium.

Ideally, in fusion reactors, whether tritium or neutron, should be preserved as an intermediate product, with only helium and heat being the waste produced.

So, it's impossible to let go of a neutron, and say whatever you want to leave it behind.

Hearing Sheng Xianfu's counterquestion, Ark smiled slightly and continued.

“Leaving them alone does not mean letting them go. Theoretically, no matter how we design the structure of the first wall, we cannot avoid the disruption of metal bonds by neutron beams. However, biased metals have too poor self-healing capabilities, and there are even more intractable problems of distortion. ”

“So why don't we set the first wall to a material that allows neutrons to pass through and self-repair, and then recycle the neutrons with liquid 63 lithium behind the first wall. As for the other side of 63 lithium, it is coated with a layer of beryllium metal for reflecting through the lithium layer of the liquid without reacting neutrons. ”

This design is equivalent to clamping liquid lithium between the first wall and beryllium.

Sheng Xianfu thought down for a while and thought that this approach seemed feasible, but always felt that there were problems everywhere.

For a while, he picked out the two most obvious questions he could think of.

“But where do you find the kind of material that allows neutrons to pass and is more self-repairing? Even after moving the lithium material to the first wall material, we are unable to address the damage to the structural material caused by neutron radiation. And, as you said, how do we get tritium back into the reactor after the first wall? ”

Hearing the two problems, the ark smiled slightly and said: “The second problem is actually not difficult to solve. At the working temperature of the liquid lithium, both tritium and helium are present in gaseous form, and the two are insoluble with each other. ”

“All we need to do is exert a weak upward force on the entire liquid lithium neutron recovery system to move the tritium produced over the entire system. ”

“Then we just need to recycle the emitted 'gas' above the entire system. ”

Tritium produced with helium as an exhaust gas is reinjected into the reaction chamber for heating ionization. And as for how to get the helium out of the reactor, that's how the filter works.

As for whether to use a water-cooled filter or a tungsten copper filter or some other filter, it's better to look at the specific needs and make your choice. This part of the technology, while critical, is not an insurmountable challenge.

Speaking of which, Ark Zhuotong went on to say, "As for your first question, you can't find this material in the alloy. So why don't we just throw the whole metal away! ”

At the moment of hearing this phrase, not only was Sheng Xianfu asking the question, but everyone in the lab, including Professor Li Changxia, was stunned.

Throw away metal material?

This…

Isn't that a bit avant-garde?

“Structural materials without metal?” Professor Li Changxia looks at the ark in surprise, "what's the use? ”

Is it ceramic?

Though there are institutes that have tried this and it works well, fatally, the thermal conductivity of ceramics is terrible.

If it is not possible to remove the heat generated from the reactor, problems will eventually arise.

“With carbon," paused for a moment, the ark said in a positive tone, "or more accurately, with carbon fiber composites! ”

This was not an abrupt idea for an ark, which he had been thinking about for a long time, even at the earliest when he had a chat with Professor Kreber at the Spiral 7-X Institute.

The carbon core is relatively stable, does not react easily with neutrons, and can act as a buffer against the neutron beam, so that when the neutron beam is in contact with the liquid lithium layer, most neutron beams do not break it directly through.

And that part of the energy that is reduced by the carbon fiber layer is released in the form of thermal energy, which, by virtue of its own good thermal conductivity, can easily derive the heat generated inside the reactor.

Heat resistance is perfectly fine.

Carbon fiber materials can withstand high temperatures above 3000 degrees when not in contact with air and oxidizing agents, comparable to the melting point of tungsten, perfectly suited to the needs of first wall materials!

At a glance at the people in the lab, the ark opens and says: "The low-activated metal material was completely removed from the first wall and replaced with carbon fiber as the first wall material and the main structural material, lithium filled with liquid in the middle layer, and the outer layer was covered with beryllium, reflecting neutrons. The shield layer is coated with paraffin and water and a mixture of boron carbide and is coated with nuclear cement. In this way, we have every hope of solving the problem of tritium retention! ”

As for the choice of carbon fiber composites and how to solve the problem of self-repair of carbon fiber composites, this subject will be studied by the Institute of Materials of the Jinling Institute of Higher Studies.

Although the problem is serious, there is hope that the Ark will be resolved!

Professor Li Changxia couldn't help but say: “This is too..."

What he's trying to say is that it's a lot to think about.

But only halfway through the sentence was interrupted by Sheng Xianfu.

“No, I don't know… that's really promising! ”

Interrupting Professor Li's words, Sheng Xianfu constantly rubbed his chin with his index finger, and his eyes became brighter and brighter.

“I have read the literature that replacing some austenitic and tungsten steel structures with carbon fiber is an equally well-liked technology route in the field of international controllable fusion! ”

“But this is the first time I've heard of replacing metallic materials completely with carbon fiber composites as the main body of structural materials and putting a decelerated beam of neutrons on the outside of the cladding material to react with liquid lithium and then recovering tritium from liquid lithium through handling. ”

The difficulty is likely to be considerable, and it is not just a matter of carbon fibre composites themselves. On temperature control, for example. The carbon fiber material of the first wall operates at about 3,000 degrees, while the boiling point of the lithium metal is only 1,340 degrees.

If heat cannot be removed in a timely manner, there is a risk of gasification of the liquid lithium throughout the Liquid Lithium Neutron Recovery System. Lightly, it is involved in the reactor along with the tritium mixture produced by the reaction, and the heavy weight may even blow up the entire reactor...

There is also the problem of volume change caused by liquid lithium coagulation when stopping the stack...

But, as the Ark has said, this line of thinking seems feasible.

At least, it's worth a try!

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(Went out yesterday to pick up material, only one more T.T. today)