Zi Yuan can be understood as a catalyst for fission. With the extra neutrons it provides, even uranium-235 below critical mass can undergo efficient fission. According to theory, both polonium and radium separated from uranium ore can combine with beryllium to form a neutron source. There are no technical difficulties involved; it purely utilizes beryllium's property of releasing a large number of neutrons when bombarded by alpha particles. In essence, as long as they are brought together, it will work. All three are naturally occurring substances, and compared to those difficult-to-handle or complex-to-produce artificial elements, their feasibility is undoubtedly much higher.
As for why Roland ultimately chose polonium over radium, it was purely for safety considerations—polonium-210 has a short half-life but primarily undergoes alpha decay, with very low gamma photon production. In other words, as long as it is not ingested, it is almost as safe as uranium. Radium, on the other hand, poses significant safety hazards, whether from the radon gas it decays into or the gamma photons it emits. To avoid accidents during the experiment, a polonium-beryllium neutron source became the most suitable choice.
Furthermore, beryllium also has the property of reflecting neutrons. If it is used as a shell, it can further increase the utilization efficiency of neutrons. If both are used together, with a sufficient amount of uranium-235, even the simplest and most reliable gun-type structure can achieve good results.
Beryllium is widely found in emeralds. This distinctive mineral saves Akima the trouble of trekking through mountains and rivers to find it. Simply releasing the news through merchant channels and widely purchasing within the Four Kingdoms will suffice.
Roland is well aware of the technological level of Neverwinter—the principle of Brilliant Radiance is simple in theory, but each 10% increase in utilization rate is a threshold. From 1% to 90%, it requires massive theoretical calculations and experimental adjustments. If high-efficiency energy release is not achieved, it will be impossible to miniaturize the weapon, and the hard-earned weapons-grade uranium will be wasted. Without Lucia, the loss from refining alone would be an insurmountable peak.
However, similarly, in situations where losses are affordable or not considered, hand-crafting a nuclear bomb is not just a joke. The technical thresholds vary greatly, but the principle remains the same. Benefiting from the inherent advantages of mass-energy conversion over chemical explosives, even if only 1% of the uranium participates in fission, its power is enough to turn the tide of battle.
In this life-or-death battle that determines the fate of the race, he will spare no effort.
Moreover, in such a barbaric era, stealing divine fire and bringing humanity closer to the sun is itself a kind of romance, isn't it?
As long as there is a glimmer of hope, he is willing to try.
"Good, keep it up," Roland patted Lucia's head. "When all the lead cabinets are filled, we can start the formal experiment."
"Yes, Your Majesty!" Lucia said with great enthusiasm.
*******************
At the same time, Neverwinter, the Air Knight Academy.
This area, located west of the new research institute and occupying a similarly vast area, was quiet—today was a holiday for the students. Most people had left the academy early to enjoy time with their families, but Goode was an exception.
"Wind, push the stick!"
"Crosswind, aileron roll!"
He sat in the flight simulator, setting the wind direction for himself while responding according to the regulations in the *Flight Manual*. The wooden rod made creaking sounds as it engaged, like an old and dilapidated waterwheel. The temperature in the training room was quite stuffy. After a long period of practice, his back was soaked with sweat, and beads of sweat dripped from his chin from time to time, splashing on the simple "instrument panel."
It wasn't until the grip slipped that Goode stopped and leaned back in his chair, exhaling a long breath.
After nearly half a year of study, he was no longer the clueless novice he once was. The *Flight Manual* written by Her Royal Highness was not only memorized by heart, but the basic operations could be said to be imprinted in his mind. From being flustered when he first got on the simulator to being able to operate according to commands with his eyes closed, if he gave the orders to himself, he wouldn't even need to say them out loud; his body would react in the first instance.
But would this allow him to fly?
No matter how he imagined it, he couldn't conjure up the scene of flying against the wind in his mind. "Capture the direction and magnitude of the wind, feel the attitude and vibration of the aircraft, and then apply the appropriate operating force"—this was the original wording of the manual, but he had no idea what that kind of feeling was like. Whether he gently pulled it halfway or pulled it all the way down, the simulator would not give him any feedback, and the "instrument panel" drawn with ink lines seemed to be mocking his efforts.
The more proficient he became in the movements, the more frustrated Goode felt.
Just as he was feeling somewhat upset, the door of the training room suddenly creaked open.
"You really are here—"
"What do you know, I guessed right, right?"
Goode turned around and looked at the two people who entered the room with some surprise—they were none other than Finnkin and Heinz from the same squad. "Why are you guys..."
"Not taking advantage of the holiday to have some fun?" Finnkin whistled. "Because the fun is in the academy."
"As for you, it's fine if you don't have family, but don't you have a cute little sister?" Heinz walked over and put his arm around his neck. "She even told me to tell you not to work too hard, tsk tsk... so nice."
Goode's expression suddenly tightened. "Wait, you two went to where I live?"
"Nonsense, where else would we look for you?" Finnkin raised his eyebrows at him. "Her name is Rachel, right? How about introducing her to us?"
"Don't even think about it," Goode glared back.
"Are you saying our conditions aren't good enough?" Finnkin retorted. "At least I have a formal residence in the Chishui River District!"
Goode was silent for a moment, and finally shook his head helplessly. "It's not about you guys, it's just that my sister... Rachel has her own problems. You wouldn't want to be with her."
"Why? I think she's pretty good," Heinz said, puzzled.
"Tell us about it?" Finnkin also looked curious.
"Don't ask about that," Goode said irritably. "Let's talk about something else—what exactly did you mean by 'fun' earlier?"
Finnkin didn't press the issue. He lowered his voice and said mysteriously, "Do you want to try a real airplane?"
Goode couldn't help but be stunned. "What did you say?"
"I saw it a few days ago when I was climbing the wall," Finnkin said with a slightly smug smile. "Several new airplanes were transported into the hangar in the airfield. Although they were covered with cloth, judging from their size, they were similar to Her Royal Highness's Unicorn. In other words, those are the airplanes prepared for us!"
"A few days ago? Why didn't you say so then?"
"I was afraid you'd get too excited and leak the news." He shrugged. "And today is a holiday, with only a few people in the academy. It's the perfect opportunity to sneak in and see them for ourselves!"
"You're crazy!" Goode said in disbelief. "We're not allowed to enter the airfield without permission!"
"Those soldiers won't let you in anyway." Finnkin rolled his eyes at him. "Of course, we'll take another route, and not go through the airfield."
"But..."
"We're just going to take a look," Heinz chimed in. "You must have felt it, Princess Tilly has been smiling less lately, and the training has been stricter. At this rate, we might have to wait another month or two before we can actually touch it. Compared to this crude wooden platform, don't you want to see what the airplanes we're going to fly actually look like in advance?"
"If you're not going, we'll take the first step," Finnkin winked.
Goode hesitated for a long time, and the dry, dull creaking of the wooden rod when he manipulated it echoed in his mind again, as well as the bewilderment of not feeling any progress no matter how much he practiced. Finally, he bit his lip and nodded. "I'll go, lead the way."