Advance notice: Most of the knowledge involved in this Chapter comes from publicly available materials from the China Institute of Engineering Physics website.
Richard read, his gaze moving across the pages.
"The first method for purifying Uranium 235 is electromagnetic separation, which uses the principle of mass spectrometry for isotope separation.
The mass spectrometer is an instrument used in laboratories to analyze the mass of charged particles, allowing particles with different masses but the same charge to be deflected at different radii in a magnetic field, thereby achieving separation.
In detail, when particles enter the magnetic field at speed v (assuming upward direction), the magnetic field lines created by the movement of positively charged particles are directed upward on the left and downward on the right. Therefore, the magnetic field on the left side of the moving charged particle is strengthened, while the right side is weakened, forming a magnetic field gradient that creates a magnetic pressure pushing from left to right.
This force is perpendicular to the velocity direction and, although it cannot change the magnitude of the velocity of the moving charged particle, it can change the direction of the particle’s movement, forming a centripetal force.
Also, because the magnetic field is uniform, the magnetic pressure exerted on the moving charged particles is equal everywhere, causing the moving charged particles to move uniformly in a circular motion within the magnetic field.
According to electromagnetism formulas, the force exerted by the magnetic field is equal to qBv, and the centripetal acceleration is equal to v2/R.
Thus, it can be derived: qBv=Mv2/R → qBR=Mv.
In the formula, q is the charge of the particle, v is the particle’s velocity, M is the particle mass, B is the magnetic induction intensity, and R is the radius of deflection of the particle’s circular motion.
Also, because the particle’s charge q and the magnetic induction intensity B are determined, the momentum of the moving particles is proportional to the deflection radius.
Ions with the same charge q but different masses, accelerated through the same voltage U, obtain equal potential energy equal to kinetic energy when entering the magnetic field: qU=(1/2)Mv2.
The previously known momentum of particles Mv=qBR allows us to eliminate v from the equations, yielding M=qB2R2/2U.
For particles with mass equal to (M+ΔM), (M+ΔM)=qB2(R+ΔR)2/2U.
This gives ΔM/M=2ΔR/R, meaning the relative mass deviation is twice the relative radius deviation.
Due to different particle masses, they gain equal energy after being accelerated by the same voltage, but their momenta differ. After entering the magnetic field, particles with larger momentum have a larger bending radius; particles with smaller momentum have a smaller bending radius.
If ions with the same momentum enter the magnetic field at an inclined angle, causing them to focus within a range D, the range D’s relationship with the incident angle can be calculated with the formula: ΔR/R≈0.5q2.
When q is less than 50, the relative error of R is 4/1000, which can cause a mass deviation of 8/1000. However, the relative mass difference between Uranium 235 and Uranium 238 is 13/1000, making mass spectrometry’s use in practical applications..."
Richard finished reading and raised an eyebrow.
This is evidently a very straightforward and understandable method. The principle is: particles with different masses but the same charge have different momenta after being accelerated by the same voltage, thereby causing different deflection radii upon entering a magnetic field.
A simple example of this is a train traveling on tracks. At a curve, a train with a suitable speed can pass through normally. Whereas, a train moving too fast would be unbalanced by the forces involved, leading to the train derailing off the track.
Using this method, Uranium 235 is like the appropriately-speeded train, while Uranium 238 is like the overly-speeded train, allowing the two to be separated, thus obtaining highly purified Uranium 235.
This method has relatively low technical content, which is why on Earth, in 1938, German chemists Hahn and Strassman discovered nuclear fission, and Meitner and Frisch proposed a theoretical explanation for nuclear fission. Only two years later, in April 1940, Neil from the University of Minnesota produced trace amounts of enriched Uranium 235 using a mass spectrometer.
Subsequently, in 1942, the Manhattan Project on Earth began, aimed at manufacturing nuclear weapons for the first time. Lawrence and others started using electromagnetic isotope separators for purifying Uranium 235.
This is a method that has been proven and is fully feasible.
However, it also has a small problem.
That is, the investment is too large.
In the Manhattan Project on Earth, for purifying Uranium 235 using this method, a massive electromagnetic facility was specially constructed at Oak Ridge. Nearly 25,000 people were involved, with more than 1,100 separators, and 15,000 tons of silver were used just to wind coils alone.
And the result was that only a few grams of Uranium 235 were produced daily. It took several years to obtain enough Uranium 235 to just barely manufacture one Atomic Bomb.
Richard pursed his lips.
He doesn’t have tens of thousands of subordinates, nor does he have 15,000 tons of silver. If he really wants to produce using this method, he must first solve the prerequisites.
If this was the only method, he might seriously have to consider establishing a private force in advance, but fortunately, this is not the only method, he has other options.
He continued reading.
"The second method for purifying Uranium 235 is the gas diffusion method.
As the name suggests, the principle applied in this method is common gas diffusion.
For example, a drop of perfume spilled in a corner of a bedroom will rapidly diffuse, and soon the entire room will smell of perfume.
If the drop of perfume is replaced with a drop of vinegar, under the same conditions, spilled in the same corner of the bedroom, it will take longer for the smell of vinegar to spread throughout the room.
This is because vinegar molecules are heavier than perfume molecules, hence their diffusion speed is slower.
Similarly, filling a balloon with Hydrogen (relative molecular mass 2) and Nitrogen (relative molecular mass 28, 14 times that of Hydrogen). When the balloon leaks, Hydrogen will leak much faster than Nitrogen because Hydrogen molecules are smaller and lighter.
Applying the gas diffusion method to Uranium elements allows separation of Uranium 235 from Uranium 238 isotopes using the same principle.
The specific operation can be conducted as follows: place Uranium Hexafluoride in an environment above 64.8°C (338.0K), where it will sublimate into gas. Then, press the gaseous Uranium Hexafluoride against a porous membrane. According to the principle of gas diffusion, Uranium Hexafluoride gas molecules containing Uranium 235 will pass through the membrane faster than those containing Uranium 238. Their diffusion rate will be inversely proportional to the square root of their gas molecular weight.
By setting the pore size of the porous membrane to be smaller than the average distance traveled between two collisions of a gas molecule with other gas molecules, the optimal condition for gas diffusion is obtained. Lighter molecules move faster than heavier molecules, passing through membrane pores more easily.
Data collection can determine that under continuous feed-in of gas, controlling the pore size of the porous membrane to be below 0.02 microns, and maintaining Uranium Hexafluoride at 85°C, results in the diffused gas (enriched stream) having a Uranium 235 concentration about 0.2% higher than the feed gas (input)..."
After reading the second method, Richard pondered.
The principle of this second method is also simple and easy to understand; it merely involves the differences in molecular motion rates in gas diffusion. By grasping this point, the content of Uranium 235 can be continuously increased.
The only issue is that data shows that each time a porous membrane is passed through, the increase in Uranium 235 concentration is only about 0.2%.
To increase the Uranium 235 content to a significant height and reach levels sufficient for actually manufacturing nuclear weapons, multiple separation stages need to be linked in series.
Moreover, simply linking one or two stages in series has little effect; thousands of stages are required.
In fact, on Earth, the Manhattan Project also adopted this method. For this purpose, a colossal factory was built at Oak Ridge, assembling thousands of separation devices in series.
This resulted in a scale that was enormous, comparable to the first method, and enormous power was needed to ensure continuous diffusion of the gas in the same direction.
For this, the entire country’s electricity would need to be tilted towards the gas diffusion plant.
It can be said that whether it is the first method or the second method, truly being put into practical operation requires the support of most of the national power of an extraordinary modern state.
Because of this, countries that can independently develop and produce nuclear weapons are considered the strongest representative forces on Earth, a symbol of absolute power. Therefore, such countries are respected and cannot be ignored.
And for Richard now, these are a bit difficult to achieve.
He pursed his lips and continued to look down.
"The third method for Uranium 235 purification is the centrifuge separation method..."
"The fourth method for Uranium 235 purification is the nozzle separation method..."
"The fifth method for Uranium 235 purification is..."
After quickly browsing most of the content, Richard shook his head.
There are indeed quite a few methods for purifying Uranium 235, almost all of which are based on the slight mass difference between Uranium 235 and Uranium 238. Compared to the first and second methods, these methods are similar, requiring high demands on manpower and resources in all aspects.
If he wants to use this method, he needs to first create a large private force.
But in his heart, it is not yet time to establish a private force.
With a slight furrow of his brow, Richard continued to read patiently and finally stopped on a page of the book.
"The ninth method for Uranium 235 purification is the laser separation method.
This is a relatively advanced method. The principle starts from the point that isotopes have different energy levels due to different masses, causing certain differences in the absorption spectrum when excited from a low energy level to a high energy level.
Thus, by selecting lasers of different wavelengths, exciting only one isotope, and using the differences in physical and chemical properties between the excited isotopes and the non-excited isotopes, they can be separated using appropriate methods.
Uranium 235 and Uranium 238 atoms and their compound molecules have been confirmed through experiments to be compatible with this method. In the experiment, using a laser to excite uranium hexafluoride gas molecules containing Uranium 235 can alter the molecules containing Uranium 235 without affecting the uranium hexafluoride molecules containing Uranium 238. After which, a second laser is used to decompose the excited molecules into uranium pentafluoride, then recover it in the form of white powder...
In fact, using atomic vapor laser isotope separation techniques, uranium metal can also be directly operated. The specific situation involves using a focused electron beam in a vacuum environment to locally heat a uranium metal ingot to 3000°C, vaporizing the uranium metal into atomic states of Uranium 238 and Uranium 235.
Then using a laser, the uranium 235 atoms in the uranium vapor are ionized by the laser, while the uranium 238 atoms remain unaffected. Using electromagnetic methods, the uranium 235 is collected, greatly increasing the purity..."
After reading this method, Richard’s eyes slightly brightened.
He could see that the laser separation method had prominent advantages compared to previous methods.
The first point is that the separation coefficient is large, and the method is simple.
The second point is that it consumes less electricity. According to some data estimates in the method, the electricity required for the laser separation method might be less than one-tenth of the diffusion method.
To know that back on Earth, the Manhattan Project consumed approximately 1700 megawatts of electricity to use the gas diffusion method, which was extremely difficult. Reducing it to one-tenth could still be barely considered.
The third point is that the size of the device is relatively small, and the manpower and resources invested do not need to be too much. Back then, the Manhattan Project used the gas diffusion method with separation stages reaching thousands, and the factory occupied an area of 240,000 square meters. Whereas for the laser separation method, a simple Level One is sufficient, greatly reducing the area required for equipment.
Overall, the laser separation method is currently the best option.
However, Richard did not draw a conclusion prematurely. He continued to read further until he finished the entire book. Then he nodded and muttered to himself, "The laser separation method is indeed easier to implement, in which case... let’s give it a try."
With that said, Richard stood up with the book and walked out of the room.
The turtle stone sculpture that Richard was sitting on regained life at this time. Crawling along, it followed Richard, crossed several oak doors, and returned to the original place, standing still.
Richard was about to walk out the library’s door with the book when he glanced towards the turtle stone sculpture, just in time to see it looking back at him.
Richard blinked and said, "Soma, the problem I encountered has been resolved, now I’m leaving."
"I’m glad to hear you say that, my Creator," the turtle stone sculpture said, its head slightly moving, "Simultaneously, I look forward to seeing you next time."
"I will," Richard smiled, and walked out of the library with the book.
Inside the library, the turtle stone sculpture’s slightly moving head stopped, its entire body froze, returning to its original immobile state, becoming a genuine stone sculpture.
Outside the library, Richard walked on the bluestone path, appreciating the scenery. After a while, he gently touched the ground and his whole body soared at high speed, rushing to the sky.
Soon, Richard broke through the atmosphere, left the planet, and arrived in the empty outer space.
Surveying the surroundings, Richard felt like he was reviewing troops, scrutinizing clusters of stars, making some adjustments.
Seeing that in some places the stars were too dense, he waved his hand to disperse them, and in places where the stars were too sparse, he waved to move stars from other areas over. Chapters fırst released on 𝙣𝙤𝙫𝙚𝙡•𝓯𝓲𝓻𝓮•𝕟𝕖𝕥
Then Richard noticed a nearby star dim and glowing red overall, its size continuously expanding, preparing to devour several planets orbiting it. This signifies that the star’s lifespan is coming to an end, having left the main-sequence star category, transitioning into a red giant star.
Casting his gaze over, Richard quickly understood the star’s system, noting all the time-sensitive information. To him, this is completely meaningless, something to be cleared away to make room for other knowledge.
Without hesitation, Richard waved his hand and squeezed the entire star system into a lump, then threw it toward a distant black hole—which serves as a recycling bin in the memory palace.
Watching the star system devoured by the black hole, emitting intense radiation, Richard turned and started adjusting other areas.
After finally ensuring that the entire memory universe had no significant issues, able to maintain long-term mobility, Richard nodded in satisfaction and left with the book in hand.
Richard spoke, causing the entire universe to collapse towards him, compressing into a singularity, then explosively releasing an incomparably brilliant light.
That light is the illumination in reality.
In the real world, on the small bed of Eden’s main laboratory, Richard slowly opened his eyes.
At this moment, his hands were empty, he didn’t bring any books out, but the relevant knowledge had already shifted to the shallow memories of his brain.
"Laser separation method, then, let’s begin,"
Richard said, blinking, and stood up and walked out.