Into Unscientific Chapter 647

Chapter 647 Yu Min's configuration comes out! (superior)

 At this moment.

Looking at Yu Min, who looked curious about the baby in front of him, Xu Yun couldn't help but be slightly startled.

 After a while.

His little heart seemed to have been tugged hard. A wave of heat instantly rushed from his neck to behind his ears, and his breathing stopped for a moment.

 Mom? !

 What the **** did I hear?

 Mentioned earlier.

Atomic bombs are a bit of a keyboard warrior thing. As long as there are sufficient nuclear materials, an atomic bomb can actually be built through a lot of experiments and trial and error.

Although the cost of this kind of trial and error will be high, the logic itself is flawless—that is, it can be built out of resources.

 But the hydrogen bomb is different.

 Any test of the hydrogen bomb before its configuration is determined is in vain, and the theoretical breakthrough of the configuration relies heavily on the flash of inspiration of a very few talented scientists.

 The most typical representatives are Taylor and Ulam, two big guys on the other side of the sea, who are also recognized as the fathers of the hydrogen bomb on the other side of the sea.

 The 1950s.

Just when all nuclear physicists were at a loss for the configuration of a hydrogen bomb, Taylor and Ulam jointly published a paper. They believed that the X-rays produced by nuclear explosions may be the key to detonating a hydrogen bomb.

 Because to meet the conditions for fusion, in addition to the extremely high temperature generated by nuclear explosions, high-density fusion materials are also needed.

 Because normally, the shock wave of a nuclear explosion will blow all nearby materials to pieces, making it impossible to form the environment required for fusion.

ˆ Tai-U thinks.

If X-rays can be released before the shock wave after a nuclear explosion. Although this time difference is as small as nanoseconds, these few nanoseconds are enough to use the energy of X-rays to trigger fusion through a cleverly designed configuration before the hydrogen bomb material is blown apart. .

This is the famous T-U configuration principle, and this is also the last paper published publicly by the two fathers of the hydrogen bomb.

Since then, they have not published any theories or data about the hydrogen bomb. The configuration of the hydrogen bomb has been classified as a top secret among the top secrets across the sea, and it will remain so even in 2023.

But on the other hand.

Although the specific hydrogen bomb configuration is highly confidential, the relevant theoretical principles of the hydrogen bomb can still be traced.

For example, the base reaction of a hydrogen bomb is inseparable from three thermonuclear reaction types, namely deuterium-deuterium fusion, deuterium-tritium fusion and tritium-tritium fusion.

This is just like if you make boiled cabbage, you will definitely need materials or equipment such as a chicken and cabbage boiler. It is the most basic issue and cannot be kept secret.

 The problem is that just knowing these three types does not make much sense at all. It is valuable only to determine a specific answer.

 Because both deuterium and tritium are extremely precious materials, and it is too difficult to prepare them at this time.

Deuterium needs to be extracted from seawater, which is very expensive. The preparation of tritium can only rely on nuclear reactors. The technology is difficult and the yield is low. In a sense, the value is far more than the same amount of gold.

The method used across the sea is to build a factory to purify deuterium from seawater, then use the extracted deuterium to artificially transmute tritium in the reactor, and then make a tritium target and a tritium beam accelerator for target shooting experiments to measure the reaction cross section of the light nuclear reaction.

This is the most natural step, but for today's poor rabbits and almost zero industrial base, the country cannot even guarantee the most basic power supply. How can such a system be built?

Although a nuclear reactor was built in China last year, its actual mission is to act as a backup for the atomic bomb. If a uranium bomb cannot be produced, the reactor will provide plutonium to develop a plutonium bomb.

 So in the original history, this nuclear reactor would not be officially operational until seven years later.

As for the temporary transfer of jobs to deal with tritium, maybe it can be done in eight or ten years, but the day lilies will be cold by then.

Therefore, the rabbits are destined to be unable to replicate the system across the sea. Their only way is to first determine which is more important, deuterium or tritium, and then choose a direction without being reckless.

This is like buying a graphics card. 4070ti, 4080, and 4090 are all pretty good. The best way is to buy them all and try them out one by one.

 The problem is that you don't have that much budget now, so you can only read various reviews to determine which card has the best value for money before buying it.

Originally, according to Xu Yun's previous agreement with the capital writer, he would tell Da Da about the matter when the time was right.

 Unexpectedly, the other side of him has already realized this before he even opened his mouth?

Then Xu Yun took a deep breath, looked at Da Da with a pretense of confusion, and asked him:

"Da Da, you also see that I have just woken up not long ago, so I can't keep up with what you just said. Can you explain the situation in detail?"

Hearing this, Da Da nodded, took the initiative to go to the window and opened the curtains (Yang Kaiqu already went to inject paclitaxel daily), and then returned to Xu Yun.

I saw him dragging a small bench to sit down, and at the same time explained to Xu Yun:

“Comrade Xu Yun, you should know that the so-called nuclear reaction cross section is a very important concept in nuclear reactions—it can even be ranked in the top few.”

Xu Yun hummed softly.

 Nuclear reaction cross section, this is actually a very interesting word.

  It does not actually describe a certain unit area, but represents the probability of a pair of particles colliding.

  But not only is its name called cross-section, its basic unit is also square meters, square centimeters, etc. of area.

 In fact, this is not surprising.

 You can first recall the concept of cross-section of the macroscopic world:

  If the radius of a sphere is r, then its cross-section is πr.

 When the motion trajectory of another sphere intersects with this section, they will collide.

 Then extend this situation to the micro field:

 Suppose there are two atomic nuclei, a deuterium nucleus and a tritium nucleus. Imagine that the tritium nucleus is surrounded by a force field, which is usually considered to be a strong nuclear force field and an electromagnetic force field.

 So the shaded area perpendicular to the direction of movement of the incident particle is the reaction cross section. Particles entering this area will enter the scope of the strong nuclear force or electromagnetic force.

 When considering the strong nuclear force, this force region is called the fusion cross section.

 The basic unit of fusion cross-section is called the bar or bar. One bar is equal to 0.8x10^-28 square meters, but 0.8 is generally regarded as 1, and then written as 10^-24 square centimeters.

Then Da Da skillfully wrote down a few numbers in his notebook and said:

“Comrade Xu Yun, during the nuclear fission process, the fission cross section between neutrons and U235 is 600 bar—this is a parameter that has been determined by many parties.”

“However, the nuclear fission cross section does not need to consider constraints. If the scenario is converted into a calculation of the fusion cross section, the electromagnetic repulsion needs to be taken into account—that is, the two target nuclei must have a certain initial velocity.”

“The T-U configuration was constructed across the sea, in which tritium accounts for a large proportion.”

“However, after I introduced the Breit-Wigner equation calculation, the entire fusion cross-section changed mathematically.”

 I saw that Da Yu first drew an image of [L] rotated 90 degrees clockwise on the paper, and at the same time his tone became less certain:

“The original cross-section image is like this, like an L flipped 90 degrees. In Chinese, it is first lifted up, and then horizontally to the right.”

 Then he drew another curve:

“But after the introduction of the Breit-Wigner equation, the fusion cross section becomes a curve when calculated to the eighth decimal place.”

“That is, even at very low temperatures, or even if two particles have very low kinetic energy, fusion reactions can occur, but the cross-section is very small.”

“And the upper limit of this cross-section is 5 bar, which is far different from the conclusion calculated above that the maximum cross-section of tritium-tritium reaction is 15 bar.”

 “At the same time, the secondary shape of this cross-section is spherical, so.”

Looking at Da Da, who was hesitating a little, Xu Yun suddenly felt a flash of realization in his heart.

I see

He felt that it was strange that the state was greater than yesterday. It turned out that he thought of the fusion cross section when he was calculating:

At that time, he was responsible for calculating the cylindrical secondary of the atomic bomb. Although this thing is not the same concept as the secondary of the hydrogen bomb, the shape of the two is still the same.

And the calculated secondary degree of greater than is a spherical shape. In this case, greater than is a natural deviation.

 But even so, Yu Yu still completed the calculation work on time, which is really scary.

 According to the original historical development.

　　It will take two and a half years at the earliest for Da Da to think of this problem. Now this can be regarded as directly accelerating the growth period of Kun Kun.

But now that things have happened, Xu Yun has no reason to hesitate anymore.

 So he quickly straightened himself up and said to Yu Yu:

“Greater than, so what you are struggling with now is that you are not very confident in your results. Or you don't know what physical concepts to use to explain this mathematical result?”

　　Da Da nodded quickly.

This is what he hesitated about.

 Mathematics does not lie in many cases, but sometimes mathematics is correct but cannot represent reality and is correct. For example, the Alcubierre metric of later generations is the analytical solution of the curvature engine.

This thing is mathematically perfect and impeccable, but have you ever seen a warp engine appear in reality? —The space-time distortion caused by the P diagram does not count.

There is also Witten's M theory, which is also a perfect example of mathematical perfection but unconfirmed physics.

Yu Yu's temperament is extremely rigorous, not to mention that the development of hydrogen bombs is related to the fate of the country, so if he doesn't figure out this issue, he will be unable to sleep for several days.

 Xu Yun then made a calm gesture towards Da Da and explained:

“Comrade Da, if you want to discuss the specific design of the hydrogen bomb with me, to be honest, I may not be able to do anything about it.”

“But this fusion cross-section involves a particle physics scenario, so to be honest, I do know a bit about it.”

“In fact, the reason for this situation is very simple, that is, the quantum effects of subatomic particles have not been taken into account on the other side of the sea.”

　　Da was stunned for a moment:

 “Quantum effects?”

 “That's right.”

Xu Yun nodded vigorously and said:

“To be precise, it is the three concepts of tunneling effect, wave effect, and resonance effect of microscopic particles.”

“Greater than, you just said that you introduced the Breit-Wigner equation, which is also the Breit-Wigner equation, right?”

“Then you must have derived the nuclear fusion variant of this equation, which is the resonance cross section for single-level neutron capture, right?”

Yu Da immediately replied, yes, and turned the notebook in his hand forward to a page, revealing a formula on it:

ˆσγ(Ec)=σ0ΓγΓ(E0Ec)121/(1+y2)+2Γ(EcE0).

When Xu Yun saw this, he secretly said that it was indeed the case.

The formula of greater than is actually not difficult to understand. E0 is the energy of the resonance peak in the center-of-mass coordinate system, which is the energy that matches Ec+ΔEb with the excited state of the composite nucleus. Γ is the total energy width corresponding to the 12 resonance peak, and σ0 is the largest cross section, Γγ is the radiation capture width.

 This is considered one of the basic variations of the Breit-Wigner equation, but some of its more in-depth physical meanings have not been analyzed yet.

 Xu Yun then thought for a while, went through his thoughts in his mind, and said to Yu Da:

“Greater than, based on this formula, you first introduce quantum tunneling, and then think about what will happen?”

 “Quantum tunneling”

Hearing this, Yu Da touched his chin twice and quickly began to think.

 Quantum tunneling.

 It refers to the phenomenon that particles cannot pass through energy barriers under classical mechanics, but have a certain probability of passing through them under quantum mechanics.

The basic principle is based on the wave-particle duality of quantum mechanics. Particles can behave in the form of waves, and their wave functions can attenuate outside the barrier, but there is a certain probability of penetrating the barrier and entering the interior of the barrier.

 Inside the potential barrier, both the amplitude and phase of the wave function are affected, while outside the potential barrier, the amplitude of the wave function decays exponentially with increasing distance, but its phase remains unchanged.

 When a particle encounters an energy barrier, its wave function will be reflected and transmitted inside the barrier according to the properties of the wave function.

Even when the energy is lower than the height of the potential barrier, the particle has a certain probability of passing through the barrier and appearing on the other side of the barrier.

This phenomenon is very common at the microscopic scale. For example, electrons passing through the energy band gap of materials, alpha rays passing through objects, etc. are all quantum tunneling phenomena. Related concepts were also proposed decades ago.

A few minutes later.

Yuda, who was deep in thought, suddenly thought of something, and his eyes suddenly lit up:

“Comrade Xu Yun, is this what you meant?”

“Due to the existence of quantum tunneling, the temperature required to overcome the Coulomb barrier is smaller than expected, and the probability of particles overcoming the electrostatic barrier increases, coupled with the Maxwell distribution approximation at the temperature under the medium.”

“So the kinetic energy of the colliding fusion particles is in a narrow energy window, resulting in a further reduction in the fusion cross section?”

Xu Yun nodded heavily:

 “That's right.”

 Quantum tunneling has a great impact on nuclear fusion. For example, the reason why the sun can naturally undergo fusion reactions is also due to the existence of quantum tunneling.

The window mentioned above is actually the famous Gamow window, but for further analysis, Lawson's criterion and three products must be added, so I won't go into details.

However, the core of Datuan's problem at the moment mainly lies in the physical properties of the cross-sectional difference, so Xu Yun only needs to help him clarify the context.

as expected.

 After being pointed out by Xu Yun about the influence of quantum tunneling.

   Soon, he focused his attention on the resonance effect.

This time Xu Yun didn't need any prompting, he quickly started his own analysis:

“If we consider the resonance effect in nuclear fusion, then it obviously refers to the 3α reaction”

“After inelastic scattering occurs, the remaining atomic nuclei are still in the excited state, and the released neutron energy must be significantly smaller than the energy of the incident neutron, that is, the load and the energy of two or more neutrons that may be released.”

"Composite nuclei may release the energy of two or more neutrons. Neutrons and atomic nuclei can interact without neutron absorption and the formation of composite nuclei. This should be explained by the resonance energy zone. Hi, I How could I not think of that? I'm so stupid.”

 “Then do this and this. Then do that and that.”

 More than ten minutes later.

Yu Da put the ballpoint pen on the table with some emotion, and a glimmer of light flashed in his eyes:

“Sure enough, the cross-sections of all light nuclear reactions are absolutely impossible to exceed 5 bar. Taylor and the others made a mistake in calculating this data!”

 Before the TU duo jointly published the seminal work, in 1950, Taylor had published a paper alone.

 The paper deduces the cross-section problem of light nuclear reactions in detail, and declares extremely confidently that the maximum cross-section of the tritium-tritium reaction is 15 bars.

The derivation process of this conclusion is very detailed, and it cannot be deliberately released to induce outsiders. At that time, several major European and American countries were studying the theoretical issues of light nuclear reactions.

 And according to the information obtained by Mao Xiong, the T-U configuration does indeed extend this theoretical result.

 In other words, all hydrogen bomb data designs across the sea are based on "the maximum tritium-tritium reaction cross-section is 15 bars."

 This approach cannot be said to be problematic, because the 15 bar scenario is obviously larger than the 5 bar scenario.

 It is equivalent to having a computer. The actual total power is 550W, but you made a mistake when calculating and calculated it as 1000W.

 So you bought a 1000W power supply. There is definitely no problem with this wattage supporting 550W - the wattage of the power supply is not afraid of being too high, just too low.

But on the other hand.

The cost of a 1000W power supply is obviously much higher than that of a 550W power supply, so the expenditure is much higher out of thin air.

  If you are a rich guy who can easily spend 50 Vs on others, this expense is nothing.

 But if you are a poor person who has to shop around to buy an egg, then the money is quite considerable.

 The current rabbits fall into the standard latter category, so the correction of this error is extremely exciting news for China and the country.

Looking at Da Da with his hands clenched into fists, Xu Yun couldn't help but smile and continued:

“So, your idea is correct. In the structural design of the hydrogen bomb, the tritium-tritium reaction can indeed be ignored and replaced by other reactions.”

"so."

What Xu Yun originally wanted to say was [just continue to calculate according to this idea], but before he could finish the second half of his sentence, Yu Yu suddenly interrupted him:

 “Comrade Xu Yun, wait a moment!”

Then before Xu Yun could say anything, Yu Yu suddenly looked at him:

“Comrade Xu Yun, if we consider quantum tunneling as you said, can we use it in material compression?”

“For example, give up certain convergence angles and form a special gradient penetrating shock wave?”

Xu Yun:

 “Ga?”

Note:

 The schedule is down, 15 surgeries

 (End of this chapter)

Chapter end