Republic of China: Ace Pilot

Chapter 833, Second Uranium Commission Report: Gun-type Uranium Bombs

Lawrence took the blueprints from Fang Wen and looked at the dense markings and changes. His gaze gradually shifted from initial scrutiny to amazement.

The two entered the office. Lawrence locked the door and laid the blueprints out on the large mahogany desk, while Fang Wen calmly began to explain the core details of the renovation plan.

"The core optimization is divided into three steps," Fang Wen pointed to the markings on the drawing. "First, correct the phase compensation deviations in the three electric fields to make up for the frequency synchronization loopholes in the alternating electric field, making the energy distribution during ion acceleration more uniform and solving the problem of beam scattering at its root. Second, fine-tune the correction coil parameters at the edges of the five magnetic poles to optimize the magnetic field uniformity, offset the trajectory deviation caused by relativistic mass increase, and reduce ineffective bombardment losses. Third, calibrate the trajectories in the two deflection regions to make the landing point of the ion beam more accurate and improve collection efficiency."

He deliberately avoided explaining the parts he had "reserved," only covering the obvious optimizations. Every modification corresponded to the problems exposed in previous experiments, and he even accurately predicted the parameter fluctuations that might occur during the debugging process, marking the solutions next to the drawings.

As Lawrence listened, he nodded frequently, his pencil moving quickly across the paper as he wrote calculations. The seriousness on his face was gradually replaced by excitement.

Fang Wen's solution not only fits the existing structure of the equipment but also avoids the technical pitfalls that the team had previously fallen into, making it fully feasible.

"Excellent, Mr. Fang!" Lawrence put down his pencil, his voice trembling with excitement. "I feel that this plan completely solves our most troublesome problem, and it's even more perfect than I expected. As long as we modify it according to this plan, the collection efficiency will definitely achieve a qualitative leap."

Fang Wen nodded: "If we modify the parts according to the parameters on the drawings, as long as the machining accuracy of the parts meets the standards, we can achieve the expected results."

However, Lawrence's expression quickly darkened, and his tone became more apologetic: "Mr. Fang, I must be honest with you. I fully agree with your optimization plan, but you cannot participate in the specific modification construction, parts production, and subsequent debugging operations."

A knowing glint flashed in Fang Wen's eyes, but he remained calm on the surface: "Mr. Lawrence, I understand. I am not a U.S. citizen, and it is normal for you to have concerns about such core military research projects."

“Yes, I’m really sorry.” Lawrence sighed. “OSRD (Office of Scientific Research and Development) has clear regulations that the modification of core scientific research equipment and the debugging of core data must be handled by engineers and technicians from the United States. I will arrange for the team’s top engineers to manufacture and replace parts strictly according to your drawings and specifications. The debugging data will be recorded throughout the process. If there are any things I don’t understand, I will need to consult you.”

"It's alright," Fang Wen replied. He hadn't planned to do it himself anyway. As long as he could watch them operate according to his plan, he could further verify his understanding of the technology, and at the same time take the opportunity to observe the details of the equipment modification and thoroughly understand the principle of each component. That was enough.

Over the next few days, the laboratory entered a period of intensive renovation.

Lawrence's engineering team was highly efficient, and with Fang Wen's precise and detailed plan, the modification work did not encounter much obstacle. In just three days, all the parts were replaced and the parameters were adjusted. An optimized 60-inch cyclotron reappeared in the center of the laboratory.

A new round of experiments began as scheduled. All the researchers were tense and expectant. Lawrence personally operated the control panel, while Fang Wen stood at the back of the crowd, calmly watching everything unfold before him.

As the instrument is started, the ion beam is rapidly accelerated and deflected in the magnetic field, and the data on the screen keeps changing. The originally scattered beam becomes stable and concentrated, and the purity value of uranium-235 at the collection port is also steadily increasing.

“15%……22%……28%……30%!” Someone couldn’t help but whisper the numbers on the screen, their voice filled with shock.

When the value stabilized at 30%, the laboratory erupted in cheers. Compared to the previous collection efficiency of less than 8%, this was a 300% improvement. Although it was still far from the high-efficiency mass production standard required for weapons-grade uranium purification, it was undoubtedly a huge breakthrough that completely broke the team's long-standing stalemate.

Lawrence turned off the equipment, a long-lost smile appearing on his face. He raised his hand to signal everyone to be quiet: "Everyone, we succeeded! This is the result of the collective efforts of our entire team, especially Mr. Fang's optimization plan, which played a decisive role. To celebrate this breakthrough, we'll have a day off. Everyone, please get some rest!"

Cheers erupted again as researchers emerged from the laboratory building in twos and threes, discussing the success of the experiment with relaxed expressions.

Fang Wen was also among the crowd, walking out of the laboratory building together, preparing to take his wife and children out for a trip during this day off.

Just then, a black Lincoln sedan drove up and stopped at the entrance of the laboratory building.

The car door opened, and two figures stepped out. Fang Wen recognized one of them immediately; he was the official from the U.S. Office of Science Development who had previously reviewed his qualifications to enter the laboratory. The other person was wearing a dark suit and carrying a briefcase, but he did not recognize him.

Fang Wen stopped in his tracks. A visit from a science and technology official of this caliber could not be a trivial matter; it was most likely related to the uranium separation project, or even the recent war situation.

He turned around without making a sound and walked towards the lawn near the laboratory building, where many Caltech students were sitting or lying down, basking in the sun and chatting, providing excellent cover.

Fang Wen found an inconspicuous patch of grass to sit down, pretending to sunbathe. He pressed the switch on the belt buckle with his fingertip and activated his superpower using his personal device.

After activating his superpower, he infused the Vertical Eye Gem with energy.

An invisible probing force penetrated the walls of the laboratory building and entered Lawrence's office.

An official from the Office of Science Development introduced the man beside Lawrence: "Professor Lawrence, this is Mr. Edwin McMillan, who was part of the Uranium Commission under the National Academy of Sciences (NAS), now renamed the S-1 Commission and formally incorporated into the Office of Science Development, directly responsible for the nuclear weaponization program."

A knowing glint flashed in Lawrence's eyes, and he quickly extended his hand: "Mr. Macmillan, I know you. I didn't expect you to come in person."

McMillan grasped his hand, his expression solemn: "Professor Lawrence, I am here on behalf of the S-1 Committee to solicit your and your team's opinions, and at the same time to share with you the contents of an important report. This report is the second nuclear weaponization report that our Uranium Committee is about to finalize, and it is also the core basis for our reporting to President Roosevelt and the military on the project's progress and future development direction."

Upon hearing this, Lawrence immediately stopped smiling and his expression became serious: "Please speak, Mr. Macmillan, our team will definitely cooperate fully."

McMillan pulled up a chair, sat down, opened his briefcase, took out a report, and explained to Lawrence point by point: "First, the report confirms a key conclusion: uranium-235 is not the only fissile uranium isotope. There is also plutonium-239, which is an isotope artificially created by irradiating uranium-238 with neutrons. It can also be triggered by fast neutrons to initiate a chain reaction. Moreover, it is less difficult to separate than uranium-235, has a smaller critical mass, and is easier to weaponize."

“This is exactly the direction we’ve been researching!” Lawrence couldn’t help but interject. “My team has already verified the fission feasibility of plutonium-239 using a cyclotron, but the current collection efficiency is not ideal.”

McMillan nodded and continued, “The report clearly assessed two technical routes: one is uranium-235 separation, whether it is electromagnetic separation, gaseous diffusion, or your cyclotron separation device, all of which are theoretically feasible, but the engineering difficulty is extremely high, the cost is high, and the cycle is very long; the other is plutonium-239 production, which is simpler in terms of technology and the material can be mass-produced through reactor irradiation and chemical separation. This is the route we recommend to prioritize, while uranium-235 research is conducted in parallel as a backup.”

He paused, his tone becoming more serious: "Another key assessment in the report is that nuclear weapons are entirely feasible within one to two years. The power of a single plutonium bomb is roughly equivalent to 1000 to 10000 tons of TNT, enough to destroy an entire city. More importantly, we have reason to believe that Germany is pushing forward with similar research. The United States must develop nuclear weapons before Germany, as this is crucial to the course of the entire war and is the core reason why we upgraded the Atomic Uranium Commission to the S-1 Commission and placed it at the highest priority of OSRD."

Lawrence quickly replied, "Mr. McMillan, I understand the importance of this task. My team has just made a breakthrough. By optimizing the cyclotron, the collection efficiency of uranium-235 has been increased to 30%. Although it has not yet reached the mass production standard, it is already a huge step forward."

“Really? That’s excellent news. I’ll add it to the report.” A hint of approval flashed in McMillan’s eyes. “The reason I’m here is to solicit your opinions on the technological approach, and at the same time, I hope you can accelerate the research progress and achieve uranium-235 separation and purification as soon as possible. In addition, the Treasury Department has approved an additional six million dollars in funding to establish a dedicated laboratory and pilot plant, completely upgrading the project from academic research to a national emergency military project. Your project will then be relocated to a new location.”

His expression turned serious as he said this.

"After several discussions by the Science and Technology Development Office, it was still impossible to agree to allow Fang Wen to continue in the project team. After all, he is a foreigner and absolutely cannot participate in the subsequent research of this project."

Lawrence was quite surprised: "But this optimization was successful because of him. If I kick him out, what will others think of me?"

An official from the Office of Scientific Development said coldly, "This concerns the interests of the United States of America. I'm sorry, you have no other choice."

“Okay, I’ll talk to him,” Lawrence said helplessly.

Fang Wen withdrew his supernatural power and lay on the grass, deep in thought.

Americans ultimately don't trust themselves, a foreigner.

However, he has already thoroughly understood the structure and operating principles of the cyclotron. Staying with Lawrence's team wouldn't lead to any further discoveries.

But another piece of news he had just overheard gave him a different idea.

Uranium bomb, plutonium bomb.

The United States is simultaneously researching two different atomic bombs.

If we could obtain the detonation schemes for these two atomic bombs, that would be the perfect outcome of this trip to the United States.

At that moment, two science and technology officials came down from the laboratory building and left in a car.

Lawrence also walked out of the laboratory building, looking deep in thought.

Fang Wen had a good impression of this person and didn't want to put him in a difficult position, so he stood up from the grass and walked over.

"Lawrence, you seem to be having some problems. You don't look well."

Lawrence looked up and saw Fang Wen, then showed an embarrassed expression.

"I... I have something to tell you. You can no longer stay in our research project."

"Why?" Fang Wen pretended not to know.

Lawrence replied, "Because the project has now become a military secret, we also need to move to a more secure location to continue our research, and as a foreigner, you have been rejected by the higher-ups from continuing to join the project."

Fearing that Fang Wen might misunderstand, he added, "I know about your contributions to the optimization of the cyclotron, but that's not something I can decide. I can compensate you in other ways."

Lawrence's words gave Fang Wen an idea.

He said, "Since I'm leaving the team, how about we go to a coffee shop off campus for a cup of coffee? I have some questions for you, as compensation for this."

“Okay,” Lawrence agreed.

The two walked out of the school and sat down in a coffee shop outside the school.

The waiter brought over two cups of hot coffee, and Fang Wen circled his finger around the rim of the cup.

Why do you think I would help you optimize the cyclotron?

Lawrence replied, "Isn't it because you want to use this technology to extract radium for medical purposes?"

Fang Wen picked up his coffee and took a sip of the unsweetened, bitter coffee: "Of course not. My motherland is facing invasion. The invaders are plundering vast amounts of resources and harming our compatriots every day. What I want to do most is to drive them away."

He paused, then looked at Lawrence: "If I could create a super bomb with immense power, capable of destroying an entire city, and drop it on their homeland, this war could end. That's my real reason for coming here."

Lawrence wasn't surprised. "I'm sorry, I can't let you stay any longer, nor can I give you the blueprints for the cyclotron."

He wasn't worried that Fang Wen, who had seen the blueprints, could remember them. Those blueprints were fifty pages thick, and even Lawrence, who drew them, couldn't remember the contents.

Fang Wen nodded: "It's a pity, it ultimately failed. But I'm not giving up. Can you tell me how to detonate a nuclear weapon?"

"Is this all you're asking for?" Lawrence asked in surprise.

“Yes,” Fang Wen replied.

Lawrence hesitated for a moment, but still made a decision.

“I can tell you, consider it your payment, but it’s impossible for you to achieve it.”

He then took out a pen and notebook, wrote on them, and then explained.

“Our detonation method is called the gun-type. Two pieces of high-purity uranium-235 material are launched like bullets. When they collide at high speed, they will instantly exceed the critical mass, triggering an uncontrollable chain reaction and then explode. This method is very simple, but the difficulty lies in the collection and purification of uranium-235.”

He paused for a moment, then added.

“There is another option. Last month, Seaborg formally proposed that plutonium-239 could be used in atomic bombs, but this substance does not exist in nature. It would require building a reactor to irradiate uranium-238 and then chemically separating it. However, its enrichment is much easier than that of uranium-235. To use it to achieve a chain reaction, a more precise method is needed.”

After saying this, Lawrence took out his wallet, gave the waiter ten dollars, and paid for the two cups of coffee.

He then told Fang Wen, "I have already paid you, so I don't owe you anything now."

Fang Wen nodded, "Yes."

He watched Lawrence leave.

My thoughts are racing; which nuclear weapons path will Mount Tai take?

Having mastered the technology for perfecting cyclotrons, it is clear that purifying uranium-235 is no longer a problem.

The gun-style design is extremely easy to implement; as long as you have high-purity uranium-235, you can make a uranium bomb.

Plutonium-239, on the other hand, has a higher neutron content, and its effect is not good when detonated by gun. It requires a more complex design to achieve the best chain reaction, which is not what Taishan needs.

In this small off-campus café, Fang Wen made the momentous decision to conduct research on nuclear weapons at Mount Tai.

He then got up and left, intending to spend another day with his wife and children before departing the United States. (End of Chapter)