Note in advance: Most of the relevant knowledge involved in this chapter comes from the official website of China Academy of Engineering Physics and public information.

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Richard reads, his gaze moving over the page.

"The first method of uranium-235 purification is electromagnetic separation, which uses the principle of mass spectrometer for isotope separation.

Among them, the mass spectrometer is an instrument used in the laboratory to analyze the mass of charged particles, which can make the particles with different masses and the same charge deflected into the magnetic field with different radii, so as to separate.

To explain it in detail, the particle enters the magnetic field with velocity v (assuming it faces upwards), and the magnetic field lines of the magnetic field generated by the motion of the positively charged particle face up and down on the left side and right side down in the direction of motion. As a result, the magnetic field on the left side of the moving charged particle is strengthened and the magnetic field on the right side is weakened, forming a magnetic field gradient that produces a magnetic pressure that pushes from left to right.

This force is perpendicular to the direction of velocity, and although it cannot change the velocity value of the moving charged particle, it can change the direction of the particle's motion to form a centripetal force.

And because the magnetic field is uniform, the magnetic pressure generated by the moving charged particles is equal everywhere, so the moving charged particles move in a uniform circular motion in the magnetic field.

According to the electromagnetic formula, it can be seen that the force of the magnetic field is equal to qBv and the centripetal acceleration is equal to v2/R.

So, it is possible to export: qBv=Mv2/R→qBR=Mv.

In the formula, q is the amount of particles, v is the velocity of the particles, M is the mass of the particles, B is the intensity of magnetic induction, and R is the deflection radius of the particles in a circular motion.

And because the particle charge q and the magnetic induction intensity B are both determined, the momentum of the moving particle is proportional to the deflection radius.

The potential energy obtained by ions with the same charge q but different masses through the same accelerating voltage U is equal, and is equal to the kinetic energy when entering the magnetic field: qU=(1/2)Mv2.

The momentum of the previously known particle is Mv=qBR, and the two equations are subtracted by v, that is, M=qB2R2/2U.

For particles with mass equal to (M+DM), (M+DM) = qB2(R+DR)2/2U.

FROM THIS, IT CAN BE CONCLUDED THAT DM/M = 2DR/R, I.E., THE RELATIVE DEVIATION OF THE MASS, WHICH IS TWICE THE RELATIVE DEVIATION OF THE RADIUS.

Due to the different masses of the incident particles, they gain equal energy after being accelerated by the same voltage but different in momentum. After entering the magnetic field, the bending radius is large with high momentum and the bending radius is small with low momentum.

If there is a skew in the angle at which ions of the same momentum enter the magnetic field, causing them to be jointly focused in the range of D. Then the relationship between the range of D and the angle of incidence can be calculated as follows: DR/R≈0.5q2.

When q is less than 50, the relative error of R is 4/1000, and the possible mass deviation is 8/1000. The relative mass difference between uranium-235 and uranium-238 is equal to 13/1000, which allows the mass spectrometry separation method to be used in practical ......"

Richard finished reading and raised an eyebrow.

This is obviously a very simple method, and the principle is that particles with the same charge of different masses have different momentum after being accelerated by the same voltage, resulting in different radii of deflection into the magnetic field.

For example, it's like a train running on a track, and at a bend in a bend, the train with the right speed can pass normally. The train that is too fast, because of the unbalanced force, will rush directly out of the track with the carriage, resulting in derailment.

In this way, uranium-235 is the train with the right speed, and uranium-238 is the train that is too fast, allowing the two to separate and thus obtain high-purity uranium-235.

This method is relatively low-tech, so on Earth, in 1938 German chemists Hahn and Strassmann discovered nuclear fission, and Meitner and Frisch proposed a theoretical explanation for nuclear fission. Just two years later, in April 1940, Neil of the University of Minnesota used a mass spectrometer to produce trace amounts of enriched uranium-235.

Later, in 1942, the Manhattan Project, the first nuclear weapon on Earth, began, and Lawrence and others began to purify uranium-235 using an electromagnetic-type isotope separator.

It's a proven approach that is entirely doable.

However, it also has a small problem.

That is, the investment is too great.

In the Manhattan Project on Earth, in order to purify uranium-235 in this way, a super electromagnetic device was built on Oak Ridge. Nearly 25,000 people have been invested, more than 1,100 separators have been used, and 15,000 tons of silver are used to wind the coils alone.

15,000 tons!

The result was that only a few grams of uranium-235 were produced per day, and it took several years to obtain the amount of uranium-235 that was just enough to make an atomic bomb.

Richard pursed his lips.

He didn't have tens of thousands of men now, and he didn't have 15,000 tons of silver, and if he really wanted to produce it with this method, he had to solve the preconditions first.

If this was the only way, he might really want to consider creating a private force in advance, but fortunately, it wasn't the only way, and he had other options.

Read on.

"The second method of uranium-235 purification is the gas diffusion method.

As the name suggests, this method applies the principle of common gas diffusion.

For example, if you sprinkle a drop of perfume in the corner of your bedroom, the perfume molecules will spread quickly, and soon the whole room will smell the perfume.

Replacing a drop of perfume with a drop of vinegar and sprinkling it in the same corner of the bedroom under the same conditions will take longer to make the whole room smell vinegar.

This is because vinegar molecules are heavier than perfume molecules, so they diffuse slowly.

Correspondingly, a balloon is filled with hydrogen (relative molecular mass 2) and nitrogen (relative molecular mass 28, which is 14 times that of hydrogen). When a balloon leaks, hydrogen leaks faster than nitrogen because the hydrogen molecules are smaller and lighter.

By applying the gas diffusion method to uranium, the two isotopes of uranium-235 and uranium-235 can be separated according to the same distance.

Specifically, it can be done like this: uranium hexafluoride will be sublimated into a gas when uranium hexafluoride is placed above 64.8 °C (338.0 K). According to the principle of gas diffusion, the uranium hexafluoride gas molecule containing uranium-235 will pass through the film faster than the uranium hexafluoride gas molecule containing uranium-238, and its diffusion rate will be inversely proportional to the square root of its gas molecular weight.

In this way, the pore size of the porous membrane is set to the average distance between the two collisions of a gas molecule and other gas molecules, and the optimal conditions for gas diffusion are obtained. It makes light molecules faster than specific molecules and easier to pass through membrane pores.

Through data collection, it was determined that the pore size of the porous membrane was controlled below 0.02 microns and the uranium hexafluoride was maintained at 85°C in the condition of continuous gas feeding. The gas thus diffused through the membrane (enrichment stream) would be enriched by about 0.2% more than the uranium-235 in the charging gas (feed)......"

After reading the second method, Richard pondered.

The principle of this second method is also very simple and easy to understand, but it is just the difference in the rate of movement of molecules involved in gas diffusion. As long as this can be grasped, the content of uranium-235 can continue to increase.

The only problem is that, according to the data, the increase in uranium-235 concentration is only about 0.2% every time it passes through a porous membrane.

In order to raise the uranium-235 content to a certain level, to a level that can actually make nuclear weapons, it is necessary to connect a number of separate stages in series.

Moreover, the series connection of one or two levels alone has little effect, and it takes thousands of levels of series connection.

In fact, this approach was taken in the Manhattan Project on Earth. For this purpose, a huge factory was built in Oak Ridge and thousands of units of separation equipment were assembled.

In this way, it is clear that the scale is enormous, comparable to the scale of the first method, and in addition, a strong power is required to ensure that the diffused gas continues to diffuse in the same direction.

For this reason, the entire country's electricity supply is tilted towards gas diffusion plants.

Suffice it to say that both the first and the second, for it to really be put into operation, will require the support of a large part of the national power of an extraordinary modern state.

It is precisely for this reason that countries that are able to develop and produce nuclear weapons on their own can be regarded as representatives of the most powerful forces on the planet and symbols of absolute strength. It is precisely because of this that such a country will be feared and cannot be ignored.

And these are a bit difficult for Richard to do now.

He pursed his lips and continued to look down.

"The third method of uranium-235 purification is centrifugal separation......"

"The fourth method of uranium-235 purification is the nozzle separation method......"

"The fifth method of uranium-235 purification is ......"

"Uranium-235......"

After a quick glance at most of the content, Richard shook his head.

There are indeed many ways to purify uranium-235, almost all of which are based on the subtle differences in the quality of uranium-235 and uranium-238. Compared with the first and second methods, these methods are similar, and they have high requirements for human and material resources.

To use this method, he needs to first create a large private power.

But in his mind, now is not the time to create a private force.

With a slight frown, Richard patiently continued to read down, eventually stopping at one page of the book.

"The ninth method for purifying uranium-235 is laser separation.

This is a relatively advanced method, and its principle is based on the fact that the isotope has different energy levels due to different masses, resulting in certain differences in the absorption spectrum when excited from low energy levels to high energy levels.

In this way, lasers of different wavelengths can be selected to excite only one of the isotopes, and the differences in physical and chemical properties between the isotopes in the excited state and the non-excited isotopes can be used to separate them by appropriate methods.

The uranium-235 and uranium-238 atoms, as well as their compound molecules, have been experimentally determined to be consistent with this approach. In the experiment, a laser was used to excite the uranium-235 uranium hexafluoride gas molecule, which could change the uranium-235 molecule without affecting the uranium-238 uranium hexafluoride molecule. A second laser is then used to break down the excited molecules to produce uranium pentafluoride and then recycle it as a white powder......

In fact, uranium metal can also be manipulated directly using the atomic steam laser isotope separation process. Specifically, uranium metal ingots are locally heated to 3000°C in a vacuum environment with a focused electron beam to vaporize the uranium metal into the atomic states of uranium-238 and uranium-235.

A laser is then used to ionize the uranium-235 atoms in the uranium vapor while the uranium-238 atoms are not affected. After electron, uranium-235 is collected by electromagnetic method, which can greatly improve the purity ......"

After reading this method, Richard's eyes lit up slightly.

He can see that the laser separation method has outstanding advantages compared with the previous method.

First of all, the first point is that the separation coefficient is large and the method is simple.

The second point is that the power consumption is low, according to the estimation of some data in the method, the amount of electricity required by the laser separation method may be less than one-tenth of that of the diffusion method.

You must know that on the earth, the Manhattan Project consumed almost 1,700 megawatts of electricity in order to use the gas diffusion method, which was too difficult. Reduced to one-tenth, you can barely consider.

The third point is that the size of the device is relatively small, and the manpower and material resources invested do not need much. Originally, Manhattan planned to use the gas diffusion method, with a separation stage of several thousand, and the plant covered an area of 240,000 square meters. The laser separation method only needs a simple one-stage operation, and the area required by the equipment is greatly reduced.

Generally speaking, the laser separation method is the best choice at present.

However, Richard did not jump to conclusions prematurely, and read it again, until he read the whole book, before nodding his head and muttering to himself: "It's still easier to implement the laser separation method, in that case...... Just give it a try. ”

With that, Richard stood up with the book and walked out of the room.

The stone statue of the tortoise, which Richard was sitting on, was brought back to life at this time. Crawling, following Richard, through several oak doors, returning to where he was, standing still.

Richard was about to walk out of the library door with his books in his hand, and he turned his head to look at the turtle statue, and he saw that the turtle statue was also looking over.

Richard blinked his eyes and said, "Suma, the problem I encountered has been solved, and now I'm leaving." ”

"Glad to hear you say that, my creator. The turtle statue spat and moved its head slightly, "In the meantime, I look forward to seeing you next time." ”

"Yes. Richard smiled and walked out of the library with the book.

Inside the library, the turtle statue's head moved slightly, and its whole body froze, returning to its original motionless state, turning into a real stone statue.

Outside the library, Richard walked along the bluestone path, admiring the scenery. After walking for a while, gently touching the ground, the whole person flew up at high speed and went straight to the sky.

Soon, Richard burst out of the atmosphere and left the planet, into empty outer space.

Looking around, Richard looked at the stars like a military parade and made some adjustments.

Seeing that the stars are too dense in some places, wave your hand to control the scattering of the stars, and see that the stars are too sparse in some places, wave your hand to let the stars in other places move over.

Later, Richard saw a dim and red-colored star nearby, growing in size, ready to devour the planets that surrounded it. This indicates that the star is about to run out of life, and has moved away from the ranks of main-sequence stars and transformed into a red giant.

Looking over, Richard soon learned about the galaxy of the star, which recorded some time-sensitive information. For him, it was completely meaningless, and he belonged to the existence that had to be cleaned up and make room for the rest of the knowledge.

Without hesitation, Richard crumpled the entire galaxy into a ball with a wave of his hand, and threw it into the distant black hole, which was the equivalent of a recycle bin in a memory palace.

Watching the galaxy being swallowed up by a black hole and bursting with intense radiation, Richard turned his head and began to adjust to the rest of the place.

Finally confirming that there was no major problem with the entire memory universe and that it was able to keep moving for a long time, Richard nodded in satisfaction and left here with the book in his hand.

"Collapse!"

Richard snapped out, and the entire universe shrank towards him, squeezing into a singularity, and then exploded, releasing a dazzling light.

That light is the illumination of reality.

In the real world, on the small bed in the main laboratory of Eden, Richard slowly opened his eyes.

At this time, he had nothing in his hands and did not bring out any books, but the relevant knowledge had been transferred to the superficial memory of his brain.

"Laser separation, let's get started. ”

Richard said, blinking his eyes, standing up and walking out.

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