I started with a ship full of max-level veterans, and I'm just a complete noob.

The next morning, Fang Xudong took the first negative out of the black paper bag in the darkroom, checked its number, and put it into the round darkroom box.

On the other side of the partition wall, Jiang Ming had already checked the grounding wire, bleeder resistor and door control contacts along the high-voltage rectifier cabinet, while Da Liu numbered each of the operating wires outside the lead glass.

Old Sun cut out lead sheets to surround three sides of the partition, pressing narrow lead strips at the seams.

The medical X-ray tube is fixed on an adjustable bracket, with the copper target window facing the polished germanium sheet cut from the middle section of the fifth furnace.

The film cassette is placed close to the sample surface, with the central aperture aligned with the target focal point and the center of the germanium wafer.

Fang Xudong checked the axis with a thin thread and then reported the first set of conditions according to the test card left over from last night: "35 kV, 5 mA, 30 seconds".

Da Liu switched on the low-voltage power supply, and the filament went from dim to bright.

Jiang Ming observed the tube ammeter through the lead glass. Only after the reading stabilized did he turn the voltage regulator to gradually send the high voltage to 35 kilovolts.

After the series current-limiting resistor is connected, the tube current falls to five milliamps, the readings of the monitoring terminal and the panel meter match each other, and the discharge branch and the gate control interlock also respond in sequence.

"Personnel, exit the cubicle. Old Sun, lock the door tightly."

Everyone retreated outside the lead shielding wall. Fang Xudong pressed the stopwatch, and Jiang Ming raised his hand to Da Liu.

The high voltage was immediately switched on, and after thirty seconds, Fang Xudong pressed the power-off switch, Da Liu closed the discharge branch, and the panel pointer returned to zero along the scale.

The negative was sent into the darkroom, where Fang Xudong developed, stopped, and fixed it in sequence under a red light. The black quickly spread from the edges to the center. By the time the washing was finished, only a dark background color remained on the entire negative.

"It's overexposed. Five milliamps is too much for this old tube." Jiang Ming put the film under the light and turned it around. The diffraction spots were all pressed into the black background, and there was no way to distinguish the layers around the central entrance hole.

He reduced the tube current to two milliamps and the exposure time to ten seconds. After the second negative was developed, several gray shadows appeared near the center, but the spots were crowded together and the edges were blended together.

Fang Xudong used a magnifying glass to search along the gray shadow twice before pointing to the location of the film cassette and asking, "Is the focus too high, or is the film too far from the sample?"

"The focal point of the medical tube can't be changed, so let's adjust the geometric distance first." Jiang Ming disassembled the sample holder, adjusted the distance between the film and the germanium plate surface from 30 millimeters to 25 millimeters, and then recalibrated the axis of the central hole.

Old Sun leaned over the lead wall, used his homemade square to press against the edge of the dark box, and confirmed that the sample holder remained in place after being locked before re-engraving the marks on the adjusting nut.

After the third negative was mounted, the tube current was still set to two milliamps, and the exposure time was changed to fifteen seconds. After Fang Xudong finished reporting the last number, Da Liu disconnected the high voltage, and only the red light of the filament gradually dimmed in the compartment.

After the darkroom door was closed, Fang Xudong gently shook the chemicals in the developing tray. A shallow circle left by the entrance hole first appeared in the center of the film, followed by a cluster of clearly separated black dots spreading out in three directions.

Jiang Ming picked up the film and moved it to the red light for inspection. The three main groups of spots rotated around the center in a corresponding manner. Although the edge spots were limited by the focal point of the old tube, the main axis of symmetry was sufficient for interpretation.

"This is triple symmetry, [111] direction." He pressed the film onto the pre-drawn transparent angle ruler, first corrected the position of the central hole, and then connected the geometric centers of the three sets of corresponding spots.

The axis of symmetry is offset from the normal to the center of the film by a certain distance. Based on the geometric relationship of 25 mm from the sample to the film, the offset angle is around 3.8 degrees, which coincides with the range measured by the polarizing microscope.

Fang Xudong compared the first and second rounds of polarization readings side by side. The extinction direction of the high dispersion germanium sheet was also biased towards the side of the curved crystal pillar. The source of error was the same in both methods.

Old Sun stood outside the lead wall, craning his neck, and after looking for a while, he reached out and took the film. He avoided the edge of the film and held the triangularly distributed spots up to the light.

"The lattice is hidden inside; taking a picture will reveal the orientation." He put the film back on the worktable, turned around, picked up the shape of the fifth crystal column to record, and waited for Jiang Mingbiao to cut the reference.

Jiang Ming drew the original fixture positioning line along the outer circle of the crystal column, and then added the real [111] main axis inside. The two lines gradually separated at the middle and tail, and the angle of 3.8 degrees fell exactly at the position where the bending record was most obvious.

"In the future, before slicing each crystal, we will take a Laue film, measure the principal axis, and then place the crystal column on the angle turntable for calibration. After slicing, we will control the nucleus and reduce the device dispersion to less than 5%."

Old Sun used a pencil to divide the angle turntable into a base, a rotating disk, and a locking seat. He left a full six degrees in the engraving range and changed the locking bolt to clamp from both sides to avoid the crystal pillar deflecting due to single-sided compression.

As footsteps approached from outside the cubicle, Wu Hanzhang walked in carrying the preliminary research plan. Just as he held up the third negative to the light, Wang Shouwu arrived at 502 with the report on the double crucible unloaded shaft system.

Wang Shouwu had placed the documents on Wu Hanzhang's desk and was about to return to the Institute of Physics when he saw three lead walls, a medical tube rack, and a negative under the light at the door of the cubicle. His briefcase immediately fell back onto the desk.

He took the film, looked at it under the work light for about ten seconds, then took off his gold-rimmed glasses, wiped the lenses, and rechecked the positions of the three main spots and the central hole.

"Back reflection Laue plot, you took it with this medical tube?" Wang Shouwu turned the film towards Jiang Ming, his finger landing next to the triple axis of symmetry.

"The copper target tube was removed from the old chest X-ray machine. It was 35 kV, 2 mA, and 15 seconds. The sample was 25 mm away from the film. One of the first two images was overexposed, and the other was too far away geometrically."

Jiang Ming handed over the exposure card and the 3.8 degree conversion paper. Wang Shouwu sat down opposite him at the worktable and checked the angle correction item by item, from the deviation of the central hole and the size of the tube focal spot to the normal of the sample surface.

For the next three hours, the two discussed the Laue film. Wang Shouwu first asked about the effect of different crystal planes on carrier mobility, and then moved on to the pairing and batch cutting process of point contact devices.

Jiang Ming overlaid the resistivity curve of the fifth furnace, the polarization reading, and the device dispersion onto the same position diagram. When the material purity and slice thickness were kept similar, the crystal orientation deviation became the most prominent variable.

Wang Shouwu flipped to the back of his notebook and pulled out a memo from two years ago. It contained a record of the Laue orientation process for germanium single crystals that he had seen at Purdue University, complete with a list of dedicated power sources, goniometers, and standard film interpretation tables.

"After returning to China, I've always wanted to integrate this process into germanium single crystal processing. The Japanese instrument at the Institute of Physics is booked for two months from now, and the dedicated orientation equipment is even more out of reach." He said, then looked at the old pipe behind the lead wall.

Wu Hanzhang was leaning against the door frame flipping through reports when he heard this, so he pushed the zero-generation sample tube data over: "We can't wait two months. The 3.8 degree has already messed up the data of 36 devices."

The conversion result of 3.8 degrees matched the polarization reading and device dispersion, and Wang Shouwu's questions became more and more detailed.

When the discussion ended, he left the report on the dual crucible axis on the table, and then took out a copy of a document on crystal plane indices and carrier mobility from his briefcase and placed it next to the third negative.

As he reached the door, Wang Shouwu glanced back at the medical X-ray tube mounted on the steel plate support, then said to Wu Hanzhang, "The things in your room are getting more and more cluttered."

Fang Xudong wrote on the last page of the discussion record that Wang Shouwu stayed for more than two hours and voluntarily left crystal surface documents, while Wu Hanzhang clipped the Laue film copy into the 24 GHz pre-research scheme.

Before leaving get off work, Lao Sun moved the steel material onto the fitter's table and carved the first reference circle of the angle turntable according to the structural dimensions drawn by Jiang Ming.

The 3.8 degrees on the film will next be incorporated into the engraving lines on the turntable, becoming a deviation that can be screwed back onto the crystal.