Chapter 433 Breakthrough in High-Temperature Superconductivity

Qian Zhiyuan placed a section of cable, broken in two, on the table. The silver-white sheath curled up at one corner, revealing the gray-black ceramic core inside. He rubbed it between his fingers and it crumbled into powder.

"Which batch is this?" He Yuzhu picked up the broken cable, the silver trim at the break resembling a gaping mouth.

"The fourth batch." Qian Zhiyuan didn't look at him, but kept his head down as he gathered the pile of scrap together. The table rattled; some cables had bubbles on their surfaces, some had their silver plating peeling off in pieces, and some were broken into fragments. "Fire ten batches, and less than three will be usable. If you re-plat the remaining three, half of them will be wasted."

He Yuzhu threw the broken cable back onto the table, where it bounced up and landed in the junkyard. "The furnace isn't working?"

Qian Zhiyuan rubbed the black ash off his fingers without saying a word. After a long while, he finally uttered a muffled sentence. "Box-type resistance furnace, temperature uniformity is within plus or minus ten degrees. The sample on the east side is overcooked, while the one on the west side isn't cooked yet. The center is 930 degrees Celsius, but the edge is only 900. To stabilize it, we need to switch to a tube furnace, the kind with programmed temperature control." He paused, "An imported one costs 200,000. A domestic one costs 80,000."

He Yuzhu didn't reply. He picked up another piece of scrap metal, dug his fingernail into an air bubble on its surface, and with a "pop," the silver coating collapsed. He glanced at his fingers; they were covered in a layer of dark gray powder. Yttrium oxide.

"I'll approve 200,000 for you. What's the yield rate target?"

"More than seventy percent." Qian Zhiyuan's voice was still muffled when he said this, but it was a little firmer than before.

On the day the tube furnace arrived, Qian Zhiyuan was already squatting in the lab unpacking it at four in the morning. The furnace tubes were made of quartz, transparent, and you could see the orange-red heating wires inside. He loaded the first batch of raw materials in, closed the furnace lid, and the numbers on the programmable temperature controller began to jump.

He Yuzhu arrived in the afternoon. When he pushed open the door to the laboratory, he saw Qian Zhiyuan squatting in front of the furnace, holding a thermocouple in his hand, his brows furrowed.

"What's wrong?"

"The temperature rise curve is incorrect." Qian Zhiyuan pointed to the screen on the temperature controller. "The preset temperature rise is ten degrees per minute, but it's only seven degrees in reality. It will take an extra half hour to reach 930 degrees, which will shorten the sintering time."

He Yuzhu squatted down beside him. The orange-red light from the furnace pipes shone on their faces, making them feel hot. "Is it a big problem?"

"I don't know. The previous furnace heated up too quickly, and this one is too slow." Qian Zhiyuan's voice sounded like it was being squeezed out of his throat. "If it's too slow, the grains will grow too big, and the superconducting phase will decompose. This furnace is probably ruined again."

Neither of them spoke. The furnace hummed, the heating element flickering on and off. He Yuzhu, his legs numb from squatting, stood up and leaned against the lab bench, watching Qian Zhiyuan.

"How long have you been squatting there?"

Four hours.

"Let's go eat."

I'm not hungry.

When the furnace temperature reached 930 degrees Celsius, He Yuzhu glanced at his watch. It was 6:20 PM. Qian Zhiyuan stood up, his legs went weak, and he had to lean on the furnace to steady himself. He didn't go to eat; instead, he took a bag of liquid nitrogen from the refrigerator, poured it into a thermos, and placed it next to the furnace to wait.

The white steam rising from the mouth of the thermos tumbled under the laboratory lights.

Forty-eight hours later, the furnace stopped. Qian Zhiyuan, wearing asbestos gloves, took the fired ceramic rod out of the furnace and placed it on the refractory bricks. The rod was jet black, with a smooth surface, no cracks, and no bubbles. He picked up a diamond knife and gently scratched one end of the rod; the cut was clean and without any chipping.

He Yuzhu stood beside him, watching him do each step. Qian Zhiyuan placed the thin slice he had cut into a liquid nitrogen thermos, closed the lid, waited a few seconds, then took it out and clamped it between the two copper electrodes. He tightened the screws on the test leads and turned on the ohmmeter. The pointer moved over and stopped steadily at zero.

Qian Zhiyuan didn't speak. He took the thin film out of the liquid nitrogen, placed it at room temperature, waited a few seconds, and then clamped it back in. The ohmmeter needle moved slightly, deviating by one division.

"How much?" He Yuzhu asked.

"One hundred and fifty Kelvin." Qian Zhiyuan's voice trembled, but he suppressed a laugh. He inserted the thin film into the liquid nitrogen again; the pointer returned to zero. He pulled it out; the pointer deviated by one notch. Liquid nitrogen, zero again. Room temperature, deviated by one notch. He tried three times, and each time the result was the same.

He Yuzhu took the pointer from Qian Zhiyuan and clipped it in himself. Liquid nitrogen, pointer zero. Room temperature, off by one notch. He handed the pointer back to Qian Zhiyuan and patted him on the shoulder. Qian Zhiyuan didn't flinch; his shoulder was stiff as a board.

When Yang Xiaobing pushed open the door, Qian Zhiyuan was stacking a newly produced batch of cables into a turnover box. Two hundred meters, one hundred and forty-four meters were up to standard. The yield rate was just over seventy-two percent.

"Director He, customs has seized a package." Yang Xiaobing placed a kraft paper envelope on the table, the scars on his face glowing dark red under the incandescent light. "It was sent from Hong Kong, and the recipient is a trading company in Guangzhou. This is inside."

He Yuzhu pulled out the photo from the envelope. Three black ceramic rods were laid out on a piece of white paper, exactly the same as the batch Qian Zhiyuan had just seen fired. A note was pasted on the back of the photo, which read, "Sample testing. If interested, please contact Mr. Chen," followed by a Hong Kong phone number.

He stared at the line of text for a few seconds. "Where are the samples?"

"Guangzhou Customs is holding it. They tested it, and the critical temperature is about 90 Kelvin, which is similar to the level published by the United States." Yang Xiaobing pulled out another piece of paper from the envelope. "And this too."

A thin sheet of white paper with only one line written on it—"For Director He."

Qian Zhiyuan leaned closer for a look, and his expression changed. "They know your name?"

He Yuzhu folded the paper and put it in his pocket. "It's not surprising that they know. Everyone on Pu Zheng's line knows Director He of the Chengshan Research Institute. They just didn't dare to pass on a message before, but now they do."

Yang Xiaobing put his hands in his pockets, his thumbs sticking out. "Customs asked me what I was going to do."

"Confiscate it as smuggled goods. Send the sample to Director Qian for component analysis." He Yuzhu glanced at the Hong Kong number. "Have Lao Sun check this number to see if it's related to Chen Yongkang."

Yang Xiaobing nodded, turned and left. Qian Zhiyuan was still squatting next to the turnover box, clutching a newly made cable in his hand, his knuckles white.

"Dean He, what does it mean that they sent samples?"

"A test. They don't know our current level, so they send a low-end one to test the waters. If we show interest, they'll assume our skill level is no more than ninety Kelvin. If we don't react, they'll know we have something better."

Qian Zhiyuan put the cable back into the box. "Should we still analyze the sample?"

"Yes. After the analysis, write a report with the conclusion, 'The sample's critical temperature is about 90 Kelvin, the process has obvious defects, and it has no reference value. Let them think we look down on this stuff.'"

Qian Zhiyuan nodded, picked out a few cables from the box, wiped them clean with a cloth, and stacked them upright in the corner.

He Yuzhu stood by the window. The streetlights in the courtyard were on, but the snow was not visible in their beams. The snow had long since stopped, and the thin layer of white on the ground had turned into dark gray water stains that made a squelching sound when stepped on.

Qian Zhiyuan walked over to him and handed him the cable. "Dean He, it's multi-core, silver-clad, with a critical current density of 100,000 amperes per square centimeter. The copper wire is only 2,000."

He Yuzhu took the cable and squeezed it. It was very soft and could be bent, unlike brittle ceramic. "Can you wind it into a coil?"

"Yes. If you replace the copper coil in the superconducting ring with this, the magnetic field can be increased from thirty Tesla to over forty." Qian Zhiyuan's eyes lit up briefly under the light, but quickly dimmed again. "The electromagnetic force will deform the coil. It needs to be combined with the carbon nanotube winding layer."

"You draft the proposal. Give it to me within a month. After the keel of the Kunlun is joined, this is the next step."

Qian Zhiyuan took the cable back and held it in his palm.

He Yuzhu turned and walked out of the laboratory. The lights in the corridor came on, and his footsteps echoed in the empty hallway. He walked slowly, his mind replaying the words on the note—"For Director He." The other person knew him, but he didn't know the other person.

He stepped into the elevator and pressed the button for the first floor. Before the doors closed, he took one last look at the brightly lit laboratory at the end of the corridor. Qian Zhiyuan was still squatting next to the storage box, his back to the corridor, fiddling with the cables.

The elevator doors closed.