Chapter 644: The atomic bomb is finalized! (Part 2)
The final form of the atomic bomb.
Hearing these eight words from Lu Guangda's mouth.
"..."
Including Li Jue Lao Guo and other base leaders, everyone's breathing stopped for a moment almost at the same time, and an inexplicable atmosphere quickly spread in the room.
The final shape of the atomic bomb...
To know.
After this hurdle is passed, all that remains is the application...that is, the problem of the parts production process.
This means that Mao Xiong's theoretical nuclear blockade will completely fail, and the advent of the atomic bomb will also enter the final countdown.
To describe it with an example from later generations...
The blood bar of the god was stripped out.
Then under the gaze of everyone.
Lu Guangda took a deep breath first to suppress the excitement in his heart, then picked up the chalk again and said:
"Comrades, now that the parameters we calculated are here, I will use this as a basis to derive the core ZND model."
"The on-site requirements are still the same as before. If there are any abnormal links or parameters, everyone can interrupt me at any time - even if it turns out that the data is not wrong in the end, it doesn't matter."
Hearing Lu Guangda's words.
Everyone at the scene nodded in unison.
Then Lu Guangda picked up the chalk and started writing on the blackboard.
Students who have watched the movie "Survival of the World" should all know this.
Li Yunlong... ahem, Lu Guangda, played by Li Youbin, once wrote a chain reaction equation on the blackboard when the project team was first established.
There are eleven steps in the chain reaction, from the initial explosive charge to the final release of energy.
But in fact, in the field of practical applications, the specific steps of the chain reaction are not eleven steps, but fifteen steps.
Of course.
This is not because the directing team or screenwriters do not understand the situation - "Survival of the World" is a gift film, with many extras who are PLAs of the army.
The actual reason for this kind of bug in the plot is mainly because the shooting time of "Survival of the World" was in 1999.
At that time, the thinking on armaments was relatively conservative, and there was still a lot of information that was far from being declassified, so the crew adopted this blurred method for filming.
But by 2023, these will no longer be big secrets.
These fifteen steps are: ignition of the detonator → explosion of detonating explosive → guidance of implosion pressure → accumulation of nuclear charge → formation of supercritical state → neutron bombardment → first-generation heavy nuclear fission chain reaction → neutron scattering → second
Generation heavy nuclear fission chain reaction → slow neutron refraction → third generation heavy nuclear fission chain reaction → moderator activation → fourth generation heavy nuclear fission chain reaction → ZND model transmits detonation wave → self-sustaining chain fission reaction
occur.
What Lu Guangda and the others are working on today is the last step before the nuclear explosion, which is the transmission of detonation waves by the ZND model.
Bah, bah, bah—
Lu Guangda quickly wrote lines of words on the blackboard with the chalk he was holding, and at the same time he was doing analysis:
"The precursor core concentration parameters can be used to derive the electron flow of spontaneous decay. Under high-density conditions and the laminar flame boundary equations, the effective delayed neutron share can be obtained..."
"By combining the two effective delayed neutron shares, the neutron generation time and the density number required for fuel can be obtained..."
"Then a part of the neutrons will be absorbed by the fuel and captured by radiation. Comrade Wei Donghang and their calculation results can correct the relative probability of this part..."
“Assuming that the average number of neutrons released each time a fission reaction occurs is ν, and we have the probability of fission after a neutron is absorbed, then we multiply these two to get the fission rate of each neutron absorbed by the fuel.
The number of neutrons is η=νσfσγ σf=ν11 a...."
Lu Guangda writes on the blackboard very quickly and can write a long line of words in the blink of an eye, but most people in the audience can keep up with his train of thought.
Same time as before.
Due to the lack of any early experience, even if Lu Guangda personally took action this time, there were some errors and omissions in the entire derivation process.
Fortunately, the on-site 'reviewers' are all very capable. Basically, within ten seconds after an error occurs in a certain link, five or six hands will be raised at the same time.
Therefore, although these errors and omissions occasionally existed, they were quickly eliminated.
Three hours later.
When the time came to half past ten in the evening.
Wow——
Lu Guangda used the last half of the chalk tip to draw a circle on the blackboard, and at the same time looked down at the audience:
"Okay, comrades, this is the ZND model we finally built."
"Among them, the thermal neutron absorption cross section σa=σf σγ, the effective proliferation coefficient is etafepPNL, and the constant source is..."
Lu Guangda quickly reported seven or eight key parameters and quickly constructed a paper ZND model.
In addition to the previous mathematical calculations, the theoretical logic of this ZND model is actually very simple:
Lu Guangda and others first calculated a constant source equation. When k>1, this equation has no stable solution. When k=1, the stable solution of the above equation is not unique.
But when k < 1, the equation has an asymptotic solution.
At the same time, when Lu Guangda and others were calculating the neutron transport equation, the theoretical team had reached a very important conclusion:
The neutron chain fission reaction device responds very violently to a 0.5% change in the absorption cross section.
On this basis.
Lu Guangda and others deduced an equilibrium equation based on the equilibrium concentration of precursor nuclei, and the expression is dC0dt=0=βνNfσfvN0?λC0.
If the cross section changes by 0.5% at time t=0, then at t=0.1s, the proliferation of prompt neutrons is [(1?β)k]1000.
In each multiplication interval l, the fission product releases λlC delayed neutrons during decay. The delayed neutron source produces (1?β)kλlC in the next first multiplication interval and (1?β)kλlC in the second interval.
[(1?β)k]2λlC delayed neutron.
And so on.
If there is a slow neutron source within the breeding interval of 1000 generations of prompt neutrons, and assuming that the concentration of fission fragments remains unchanged (C=C0), then the number of neutrons after 0.01s is:
Then by introducing the detonation equation, the ZND model can be obtained.
It's very simple and easy to understand, as long as you have some hands on it.
With the successful establishment of the ZND model, the rest is...
Introduction and calculation of parameters.
Of course.
At this point, pure manpower is definitely inappropriate...or not safe - after all, the stakes are so high.
Therefore, in addition to human calculations, computers are also an indispensable auxiliary item.
So soon members of the theory team extracted these key data and formulas and sent them to the ground to the computer center for simultaneous derivation - when the Taishang project was established, the 104 machine had already been sent to the base.
Now several experts from the Computer Institute are on standby on the ground, ready to input and calculate parameters at any time.
However, Lu Guangda and others did not sit still, but continued to make calculations.
If more than one party is involved in the calculation, there is an additional guarantee. When the time comes, all parties can summarize and compare the results.
Then very quickly.
The sound of crackling abacus could be heard in the conference room.
"The small beads advance one, the big beads retreat one..."
"Two up, three down, five..."
"Three hundred and fifty-seven times four point ninety-nine, the result should be..."
Abacus made of different materials emitted sounds of different frequencies when moved with different strengths, forming a brisk and beautiful movement in Xu Yun's ears.
But soon, Xu Yun realized a "truth":
What moved him was not the sound of the abacus, but the... people who were doing the abacus.
Da Da, Lu Guangda, Wang Ganchang, Cheng Kaijia... How could the music played by these seniors with their hard work and loyalty not sound good?
Suddenly, Xu Yun remembered a piece of news he saw before traveling through time:
After three years, a certain domestic mobile phone brand developed a domestic 5G chip despite layers of blockade across the sea.
This news may seem like a commercial competition, but behind it is a game between countries.
Although Xu Yun didn't know what kind of story was behind that chip, what was certain was that in that time and space, there must have been a group of people who were equally unwilling to admit defeat, holding up the stars in the sky and driving with faith and passion every night.
new road.
Time can change many things, but it cannot change many things.
Then Xu Yun suddenly thought of something and quietly pushed his wheelchair to Li Jue's assistant Zhou Cai:
"Assistant Zhou, do you have a camera with you?"
"camera?"
Li Jue was slightly startled, and seemed a little surprised by Xu Yun's words, but he quickly nodded:
"I have it with me. I was responsible for taking photos for many news about the base. Consultant Xu, what's wrong?"
Upon hearing this, Xu Yun turned around and pointed to the calculation room where the abacus was being clicked, and said:
"Assistant Zhou, can you take some photos of the scene? - Although our project is still top secret now, maybe it will be gradually declassified in a few years?"
"If we take some photos now, if we don't preserve them all, they will be precious historical images."
"In case someone questions something...for example, we don't actually use a lot of calculations to calculate the data, then we will have evidence to counterattack."
When he said these words, Xu Yun's tone contained a subtle emotion that he had not even noticed.
In his future life after traveling through time.
The so-called "Rabbits didn't use much calculation in the atomic bomb project" can often be seen. Xu Yun recalled these things earlier.
Xu Yun thought he was used to these remarks, but what he didn't expect was...
With the release of a movie called "Oppenheimer", the enthusiasm about the rabbits' development of the atomic bomb has actually been aroused.
Some of them are positive news, such as the deeds of senior science popularizers like Lu Guangda, or introductions to the difficulty of developing nuclear weapons at that time.
But there are still some so-called "reasonable guests":
Suddenly there are a lot of "science popularization" rabbits on the Internet. People who had computers back then said [the abacus is just a propaganda tool, and the difficulty of abacus calculation is xxxxx]...
Faced with those remarks, Xu Yun was really helpless.
The Rabbits' 104 machine indeed made a great contribution to the research of the atomic bomb. He has never denied this.
But the problem is that the computing power of the 104 machine is only 50,000 times per second. Even if the 104 machine is fully loaded at that time, it cannot afford the data calculation of the atomic bomb.
It's not that they don't know that the efficiency of an abacus is definitely lower than that of a computer, and it's not that they want to seek abuse for nothing, but that the conditions at the time forced them to use an abacus to assist.
Just like many working-class workers nowadays either take the subway or ride an electric donkey to work. Are they afraid of heights and that’s why they don’t want to fly in a helicopter?
The answer is obvious.
But the logic of those people now is equivalent to focusing on those people who have the ability to fly in helicopters.
Then he said [The scientific and technological conditions of 2023 have already made some helicopters popular. For example, xxx of xx Group used a helicopter to go to work at that time]...
In fact, it’s not just rabbits. At that time, Xu Yun also saw someone under a video of the drama "Oppenheimer" saying that when developing nuclear weapons across the sea, computers with a computing power of 1 million per second were used...
.
Perhaps for some people, it would give them some pleasure to use other methods to deny the abilities of the strong.
This chapter is not over yet, please click on the next page to continue reading! So in order to silence those people, Xu Yun suddenly came up with an idea:
Why not take a photo at this most crucial time?
To know.
In 2023, when Xu Yun traveled back in time, although there was a lot of photo information on Base 221, they were basically all in the same format:
There are one or two tractors or other equipment parked in the back of an open space. There are three or four men and women in shirts standing on the open space. The gay men have their hands behind their backs and one foot (usually the right foot) in a gesture similar to "take a break"
"But in a more casual posture, she stretches forward slightly, while the lesbian crosses her left and right hands in front of her body, with a bright smile with a hint of restraint on her face...
Apart from these "formats", there are very few images that are really related to computing.
Currently, apart from the 11 related photos on display at Atomic City, there are only about five or six photos that have been circulated through different channels (such as the person being photographed).
The reason for the lack of this information is not because of the high level of confidentiality, but because people at the time did not realize that this information would be so valuable - it is no exaggeration to say that when the base was first established, many people had no idea whether an atomic bomb could be developed.
How confident...
Moreover, even with the brains of Lu Guangda and Da Da, I am afraid that no one would think that someone would make an issue out of the abacus in future generations.
Therefore, due to various reasons, the rabbits really have very few images of the calculation process.
Now that there is this opportunity...how could Xu Yun not seize it?
Although Zhou Cai could not understand Xu Yun's inner thoughts, let alone know about some of the controversies decades later, he personally was not very disgusted with Xu Yun's suggestion.
After all, purely from a commemorative point of view, there is nothing wrong with taking a few photos of the scene.
So he quickly made a wait gesture to Xu Yun, came to Li Jue and whispered a few words to him.
Li Jue's brows were raised slightly, and he quickly nodded.
Immediately afterwards, Zhou Cai returned to Xu Yun and slowly took out a small bag from the edge of his seat:
"Consultant Xu, the factory director has agreed to take pictures. Please wait a moment while I debug my baby first."
Xu Yun had no objection to this.
Zhou Cai then placed the small bag on the chair, opened the zipper, and carefully took out a camera.
This camera is completely different from the SLRs of later generations. It is a rectangle about seven centimeters wide and nearly fifteen centimeters high.
Its sides and back are black, and the front is silver-white. There are also two lenses on the front.
The upper lens has only one lens, while the lower lens has some scales, and it seems that it can be rotated and adjusted.
Seeing Xu Yun staring at the camera curiously, Zhou Cai couldn't help but reveal a smile:
"How's it going, Consultant Xu, does my baby look good?"
"To tell you the truth, this is a Brownie camera produced by the Eastman Kodak Company across the sea. It has an upper and lower lens structure. It has three aperture settings: large, medium and small. The shutter speed is 1/25, and there are two stops in B."
"In order to import this camera, the capital spent a lot of foreign exchange. There were only about ten in the country."
Looking at Zhou Cai talking eloquently, Xu Yun suddenly felt a sense of déjà vu in his heart as if he had seen a future SLR enthusiast...
Zhou Cai then walked to the front of the calculation room and took photos.
The camera's flash slightly affected the calculations of some project team members, but no one said anything about it. After all, it was acceptable to retain some images during such a critical period.
At the same time, Li Jue sneaked up to Yu Da at some point, pretending to be discussing something, and deliberately asked Zhou Cai to take a close-up.
This operation inexplicably reminded Xu Yun of Dean William Whewell in the 1850 copy. He seemed to have done a similar operation in Pluto Night...
However, Xu Yun suddenly thought of something after Zhou Cai took a few photos - his face seemed to be included in the photo.
However, Xu Yun quickly shook his head and threw this idea behind him.
Just take it, since your face is already disfigured, what else can happen?
impossible!
More than ten minutes later.
Zhou Cai adjusted the camera and returned to Xu Yun:
"Consultant Xu, the rubber ring has been photographed, do you still want to continue?"
Xu Yun glanced at him:
"How many pictures were taken in total?"
"The capacity of the film is 36 pictures. I took seven pictures on this roll of film the day before yesterday, so I took a total of 29 pictures today."
"29 pictures..."
Xu Yun touched his chin when he heard this:
"That's almost it. Any more will easily affect the calculation efficiency of all comrades, so let's stop here."
"okay!"
Then Xu Yun, Zhou Cai and others waited obediently in the rear, no longer affecting the calculations of the big guys in front.
........
More than four hours passed.
When the time came to nearly three o'clock in the morning, DaDa was the first to submit his own data.
Then came Chen Jingrun...
Then came Cheng Kaijia, Zhou Guangzhao and others...
Four o'clock in the morning.
All project team members gathered all the data into Lu Guangda's hands.
At 4:20 in the morning, the computer team's reply also came back from the ground.
Then Lu Guangda, Peng Mengxiong, Zhou Guangzhao and others worked together to sort out the information, and finally at 6:17 in the morning...
A complete atomic bomb design drawing is officially released!
........
at the same time.
Far away across the ocean.
A man who looked very happy looked out the window at the dim night scene and couldn't help scratching his hair.
The weather has been nice recently, and it seems that I can find a chance to go out for a drive in a convertible...
...
Note:
I coded 5,000 words in hospital, please give me some monthly votes...
