171: Chapter 171 Twelve Mirrors, the Lunar Stack Illuminates in One Go!

Alien civilization navigation timer, Day 54.

Pangu Laboratory B2 level, 1:00 AM.

Su Che fed the wavefront correction algorithm for the third virtual mirror into the simulation space and ran it once; the convergence curve didn't flatten out, and the tail end had a small spike.

The cumulative wavefront distortion after connecting three mirrors in series began to appear.

The correction accuracy for a single mirror was sufficient, but every time the beam passed through a mirror, a layer of residual distortion was added.

It was barely noticeable with two mirrors, but it started showing with three.

"Superposition amplification effect."

Zhao Mingyuan hadn't slept; he had been working on the kinematic planning for deposition arrangement at the adjacent workstation. Hearing the prompt indicating that Su Che's simulation had finished, he tilted his head to glance at the data.

Su Che didn't reply, pulling out the distortion transfer matrix for the three mirrors to compare them item by item.

The problem lay in the optical path turning angle between the second and third mirrors.

The larger the turning angle, the larger the angle between the incident wavefront and the mirror normal, the more violent the polarization state rotation, and the easier it was for the actuator's compensation direction to deviate from the actual distortion direction.

In the optical path layout, he changed the turning angle of the third mirror from 32 degrees to 19 degrees.

Rerun.

The tail of the convergence curve flattened out.

The cumulative distortion of the three mirrors in series was suppressed back to the single-mirror level.

Su Che typed a line in the code comments: "Turning angle must not exceed 22 degrees, otherwise polarization state rotation will cause correction failure."

This rule needed to be applied to all subsequent mirrors.

The optical path of the twelve mirrors needed to be rearranged, with every turning angle kept within 22 degrees.

He opened the overall optical path diagram in the machine architecture blueprints.

The twelve mirrors were originally designed in a compact arrangement, with turning angles ranging from 15 to 41 degrees.

Now that they all had to be pressed within 22 degrees, the optical path length would be extended, and the overall volume of the machine would have to increase accordingly.

Su Che measured the space required for the new layout.

It was 40% larger than the original design.

It could fit into the Dry Dock's manufacturing cabin, barely.

He saved the new overall optical path diagram and noted the reasons for the changes and the constraints.

3:30 AM.

Lin Waner walked in from the side door.

She didn't turn on the main lights, walking to Su Che's side by the light of the console screen.

She was carrying a small tray with a bowl of white fungus soup and a pack of tissues on it.

She set down the white fungus soup.

She pulled out a tissue, swept the pile of peanut shell debris beside Su Che's keyboard into her palm, and threw it into the wastebasket.

"It's three o'clock."

"I know."

"The tape on your hand has fallen off."

Su Che raised his right index finger to take a look.

The medical tape he had applied yesterday had rubbed off at some point, leaving a ring of adhesive residue on his callus.

Lin Waner took a roll of tape out of her pocket, tore off a piece, and reapplied it.

"The reminder function is still there."

Su Che picked up the white fungus soup and took a sip.

It was warm, and the sweetness was very low.

"Write for another hour."

Lin Waner didn't argue and turned to leave.

Su Che set the white fungus soup aside where it wouldn't be in the way and switched back to the optical path code.

Four, five, six mirrors.

Every time a mirror was added, the parameter space of the wavefront correction algorithm expanded by one dimension.

By the time the simulation of six mirrors in series was finished, the time taken had increased from a few seconds to twenty minutes.

He needed a recursive framework to feed the output residual of the previous mirror directly into the initial correction value of the next one, rather than calculating from scratch every time.

Recursion.

A classic technique in cybernetics.

Su Che turned his head to look at Zhao Mingyuan's workstation.

He had fallen asleep with his head on the keyboard.

His left cheek was pressing on the space bar, and over three thousand spaces had rolled across the screen.

Su Che didn't wake him up.

The idea for the recursive framework could be grafted from the auxiliary field source topology optimization that Zhao Mingyuan had mentioned during the day; someone with a strong foundation in cybernetics could write this faster than he could.

He would wait until he woke up.

Su Che wrote a rough recursive shell himself and reran the series simulation of the six mirrors.

The time taken was reduced from twenty minutes to four minutes.

The accuracy didn't drop.

He saved the shell into a temporary branch, finished the rest of the white fungus soup, and turned off the screen.

5:15 AM.

The air conditioning on the B2 level was humming.

Zhao Mingyuan's face was still pressing on the space bar.

Su Che walked to the folding bed and lay down, the metal crossbar digging into his back through the thin mattress.

...

Alien civilization navigation timer, Day 56.

10:00 AM.

Zhao Mingyuan took the recursive shell written by Su Che and revised a version, speeding up the loop convergence rate by another 30%.

"You wrote this shell too crudely."

He pushed the modified code to the public repository. "You used hard copying for the initial value transfer; I changed it to reference passing, and the memory usage was cut in half."

"As long as it runs, it's fine." Su Che was already using the new shell to connect the eighth mirror.

Eight mirrors.

The cumulative distortion did not diverge under the suppression of the recursive framework.

The convergence speed of the wavefront correction stabilized at within two minutes per mirror.

The ninth mirror.

The tenth mirror.

When it reached the eleventh mirror, there was a problem.

The incident beam of the eleventh mirror had passed through the gradual focusing of the previous ten mirrors, and the light intensity density had increased by six orders of magnitude.

Under this light intensity, the actuator produced a weak photothermal deformation; the piezoelectric ceramic absorbed a portion of the light energy, its own temperature rose by 0.003 Kelvin, and the volume expansion caused the mirror surface curvature to shift.

0.003 Kelvin.

In other engineering projects, this would be noise within noise.

But sub-nanometer work doesn't tolerate noise.

Su Che added a layer of thermal compensation coefficient to the actuator model, calculating the effect of photothermal deformation into the feedback loop of the wavefront correction.

Rerun.

The eleventh mirror passed.

The twelfth mirror.

The last mirror was the terminal focusing mirror, from where the light spot hit the substrate.

All the residual distortion accumulated by the previous eleven mirrors underwent a final convergence here.

Su Che fed all twelve mirrors' parameters into the recursive framework and pressed Enter.

The simulation ran for eleven minutes.

The intensity distribution map of the terminal light spot popped up.

The central peak was sharp.

The edges were clean.

Light spot diameter: 0.049 nanometers.

It was 0.001 nanometers larger than the 0.048 during the simplified verification with two mirrors.

The cumulative cost of twelve mirrors in series was only one picometer.

"Optical path locked." Su Che locked the complete parameter configuration of the twelve mirrors into the encrypted storage.

Zhao Mingyuan raised his head from the deposition arrangement code and glanced over.

"You connected all twelve mirrors in this one week?"

"The recursive framework saved the bulk of the work." Su Che stretched his shoulders. "How about you?"

"The kinematic planning for the deposition path is 70% done."

Zhao Mingyuan snapped his laptop lid shut.

"The parametric modeling of the atomic beam trajectory from separation to landing is fine; the problem is the scheduling logic for multi-atom parallel deposition. Depositing single atoms one by one is too slow; I need to control dozens at the same time, and isolating the crosstalk of the quantum field is a pitfall."

Su Che didn't reply; he could only use the ultimate quantum isolation medium provided by the system, but he hadn't redeemed that yet.

Point matters couldn't be rushed.

He stood up, bypassed the console, and walked toward the east side.

...

The atmosphere on Liu Huaqiang's team's side was different.

Their project progress was two days behind the original schedule.

In the open space in the middle of the U-shaped array, the beryllium-copper alloy reactor model had already been disassembled and reassembled twice.

Wen Bo had replaced all 3,400 self-locking wedge washers, all installed in place, and every single one had been calibrated with a torque wrench.

"The joint simulation is finished." Liu Huaqiang stood in front of the whiteboard, a mechanical pencil hanging in his mouth, speaking vaguely.

He took the pencil down.

"Blue plan, all four subsystems passed. Reactor startup, Helium-3 separation module integration, temperature control preheating, and neutron shielding layer stress are all within the safety envelope."

Wen Bo crouched next to the model to check the torque value of the last washer.

"What about the structural stress under lunar gravity conditions?" Su Che walked to the whiteboard and scanned the data.

"Academician Li Zhengyang's third-order thermal expansion compensation coefficients have all been fed in."

Liu Huaqiang opened the bound document and pointed to the signature column on the last page. "Worst-case scenario: alternating cycles of 127 degrees at lunar noon and negative 173 degrees on the shaded side for 1,000 times; structural deformation is within 0.01 millimeters."

"Energy station R&D is finished." Su Che scanned the data and made a direct conclusion.

Liu Huaqiang tucked the pencil back behind his ear.

"I have already pushed the production list of prefabricated parts to Zhou Dehai, and the production schedule for the Zhulong at Kaitian Base..."

"Wait a second."

In Su Che's consciousness space, the mechanical voice popped up on time.

[Ding! Lunar side quest "Lunar Lamplighter" completed!]

[Full system joint simulation of the small-scale Controlled Nuclear Fusion energy station on the moon passed! The four major subsystems—reactor structure, Helium-3 separation module, neutron shielding layer, and temperature control system—have all met the standards, and the 1,000-cycle verification of extreme lunar surface conditions shows no abnormalities!]

[Task reward: 100,000 skill points!]

Immediately after—

[Ding! Detected extreme temperature difference risk in the operational stability of the lunar energy station, lunar side quest triggered!]

[Task name: Don't let the furnace on the moon run hot and cold!]

[Task content: The temperature difference between day and night on the lunar surface is nearly 300 degrees, and the operating temperature of the fusion reactor can easily reach tens of thousands of degrees. With repeated hot and cold cycles, even the toughest furnace will crack! Please develop an improved temperature control module for the lunar fusion reactor to solve the problem of stable operation of the fusion reactor under extreme temperature differences!]

[Task reward: 60,000 skill points, unlock redemption rights for fusion reactor extreme temperature control technology, thermal insulation material adaptation technology, and precision temperature measurement and control technology, requiring 30,000 redemption points.]

[Current host independent point balance is sufficient, redeem?]

"Redeem."

[Ding! Consumed 30,000 independent points, core technology unlocked!]

[System prompt: Supporting auxiliary technologies have not been redeemed, including: temperature control module blueprints (3,000 redemption points), thermal insulation adaptation scheme (2,000 redemption points), temperature control algorithm library (3,000 redemption points), total redemption points: 8,000.]

"Redeem all."

[Ding! Consumed 8,000 independent points.]

Su Che closed the consciousness panel.

The second lunar task was connected.

The temperature control module was the life-saving component of the energy station; without it, the fusion reactor couldn't run for more than three day-night cycles on the moon.

The foundation for this technology had already been accumulated in the previous miniaturization of Controlled Nuclear Fusion and Wen Bo's heat dissipation scheme, so the difficulty was not high.

"Dean Liu." Su Che turned to Liu Huaqiang, who was still standing in front of the whiteboard. "The lunar energy station is finished. Next item: fusion reactor temperature control module. I already have the technical framework; can we get it done in three days?"

Liu Huaqiang took the pencil down from his ear and drew three boxes on the whiteboard.

"Thermal insulation material adaptation goes to Wen Bo, I'll write the temperature control algorithm, and let Academician Li Zhengyang decide the precision measurement sensor selection."

"Three days is a bit tight." Wen Bo stood up, the goji berries in his enamel mug soaked and swollen. "The thermal insulation material needs to undergo accelerated aging under lunar surface temperature difference conditions; at the fastest, it will take a full 48 hours to run."

"Then three and a half days." Su Che didn't say anything more.

He turned and walked toward the main console.

When passing by the monitor wall, he glanced at the central screen.

400 kilometers in altitude.

The shell of the Dry Dock's enclosed final assembly module had only a small blank space left at the top docking module. Five hundred silver-gray robots were densely packed in that area, the white light of welding torches flashing one after another.

In a few more days, this space factory would be completely topped out.

Su Che sat back at the main console.

Optical path locked.

Zhao Mingyuan was working on the deposition arrangement.

The second lunar task started.

He opened the next code block for the Sub-nanometer lithography all-in-one machine, the upper-layer scheduling interface for the deposition arrangement scheme.

Zhao Mingyuan was responsible for the underlying kinematic planning, and he would write the upper-layer scheduling.

The two people's code would eventually have to interlock.

The handheld device vibrated.

A message sent by Academician Zhang Weide from Wenchang Launch Base.

"The center-of-gravity balancing for the lunar energy station's beryllium-copper alloy vacuum chamber is complete. The first batch of components will be loaded onto the luan bird verification ship tomorrow and sent to Jiuquan Launch Base."

Su Che replied with "Received" and placed the phone face down on the table.

He typed the first line of scheduling code.

On the east side of the B2 level, Wen Bo had already dug out samples of three types of thermal insulation materials from the toolbox and lined them up on the console.

Academician Li Zhengyang walked over carrying a thermos, bent down, and looked at the sample labels.

"Aerogel, zirconium carbide ceramic, alumina fiber felt. In the lunar surface vacuum environment, the thermal insulation principle of aerogel fails."

"So aerogel is just there to make up the numbers."

Wen Bo used tweezers to move the aerogel sample aside. "The real candidates are the latter two. Zirconium carbide has a high temperature resistance limit, but it is brittle. Alumina fiber felt has good toughness, but its thermal conductivity is an order of magnitude higher than zirconium carbide."

"Composite." Academician Li Zhengyang took a sip of water.

"No kidding, obviously composite." Wen Bo was already cutting the samples. "The problem is the composite ratio and the interface bonding process; that's where the time needs to be spent."

The two didn't chat any further and went back to their respective work.

Liu Huaqiang created a new code repository for the temperature control algorithm on the terminal, with the file name "Lunar Radiator."

On Su Che's screen, the number of lines of scheduling code was increasing line by line.

In a small window in the corner of the monitor wall, the real-time image of the Near-Earth Orbit Base was quietly refreshing.

The main frame welding was finishing up, and the shell of the energy module had already been closed.

Everything was moving forward.

No one stopped.