The bubbles in the liquid can be stably suspended and pulsate periodically under the drive of a certain sound field. In the collapse phase, the bubbles can produce a volume compression ratio of millions and high temperature and pressure on the order of picoseconds. When the driving sound pressure is large enough, the energy build-up causes the bubbles to glow, a phenomenon known as sonoluminescence.

In the right actuation case, the acoustic luminescent bubble can remain spherical, and the nonlinear vibration can be repeated precisely for millions or hundreds of millions of cycles. And it is precisely this characteristic that provides a possible idea for achieving controlled fusion at relatively low temperatures.

At this moment, inside the Jinling Institute for Advanced Study.

The center of the acoustic laboratory of the Institute of Physics has been temporarily requisitioned by a controlled fusion miniaturization research team led by Lu Zhou. In the center of the laboratory is a transparent container with a radius of about three inches.

The whole transparent container is filled with clear and viscous concentrated sulfuric acid, high-power ultrasonic generators are connected to both sides of the container, and various precision instruments and equipment are displayed around the whole set of equipment, ready to collect experimental data.

Since the phenomenon of acoustic luminescence occurs in picosecond flickering, it is difficult for ordinary laboratory cameras to collect all the flash information, especially when the bubble collapses to a minimum.

For this experiment, Lu Zhou even borrowed the only set of "lock-in integral imaging experimental system" from the Jinda Acoustics Research Institute.

In addition to some special acoustic experiments, this system is generally used to study anti-submarine sonar, and if it were not for the sake of Lu Zhou's face, the director of the acoustic research institute would not have agreed to lend the equipment.

Standing next to the experimental device, Sheng Xianfu, who had already completed the experimental preparations, set his eyes on Lu Zhou who was standing aside.

Lu Zhou nodded and spoke.

"Let's get started."

"Yes."

Taking a deep breath, Sheng Xianfu walked to the nearest computer and quickly knocked down a few buttons.

As a short mosquito sound passes, the high-powered ultrasonic generator begins to release ultrasound waves carrying enormous amounts of energy into the solution.

Confirming that the sound pressure in the working liquid had reached the standard of 5 times the atmospheric pressure, Lu Zhou immediately continued to order.

"Inject xenon!"

"Yes!"

As xenon gas is injected, a bubble slowly rises from the bottom of the container and floats in the center of the container driven by the sound field.

Immediately after that, the power of the ultrasonic emitter begins to gradually amplify, and the sound pressure applied to the bubbles also increases.

At the moment when the sound pressure acting on the bubble reaches 15 times the standard atmospheric pressure, the xenon gas bubble floating in the concentrated sulfuric acid is like a bright light, flashing purple to whitish in an instant!

Seeing this scene, the researchers gathered around the experimental device showed a hint of joy on their faces.

While this is only a test of the experimental setup and is still a long way from true success, it is certainly a good start.

The bubbles suspended in the working liquid flashed 10 groups of light in a row, and the photos in the luminous state were collected by the lock-in integral imaging experimental system, and several acoustic physicists from the Institute for Advanced Study immediately analyzed the photos and determined the luminescence temperature and power through the spectrum.

After receiving the experimental data from Sheng Xianfu's hands, Lu Zhou briefly glanced at it twice.

The luminous power is around 130, and although it is only a momentary flicker, it is quite amazing. As for the peak temperature of the bubble surface, the most prominent group has reached a terrifying figure of 1.5 million Kelvin, like a star floating in solution!

Of course, this data is not necessarily accurate.

After all, the collapse of bubbles happens in a split second, and it is not easy to measure the temperature of this moment indirectly, let alone reduce the error of the data.

"The results of the first phase of the experiment are very successful, let's move on to the next stage," Placing the experiment report on the table, Lu Zhou continued to instruct Sheng Xianfu who was standing next to him, "Add a neutron shield to the container and prepare to inject a mixture of deuterium and tritium!" ”

Sheng Xianfu nodded seriously: "Yes!" ”

The first stage of the experiment was only to test whether the design of the device was reasonable, and whether it could provide enough sound pressure for the bubbles to reach a temperature of more than one million Kelvin in an instant.

Now, it seems, their experiment was a success.

When the xenon gas floating in the working liquid is compressed to a point that is imperceptible to the naked eye, the energy condensed in one point releases a brighter light than a point on a star.

Although the temperature of the million Kelvin level is still far from the ignition conditions of controlled fusion, the conditions that promote controlled fusion are not only the temperature.

The sound pressure acting on the bubble not only brings millions of Kelvin heat to the bubble, but also brings a terrifying density!

And density is also one of the conditions for fusion reactions!

At Lu Zhou's instructions, the researchers in the laboratory put the transparent container into a black box made of neutron shielding material, turned off the lock-in integral imaging system, and then repeated the previous experimental procedures.

It's just that the gas introduced has been changed from xenon to deuterium-tritium mixed gas, and the generation power of ultrasonic waves has also increased from the original order of magnitude to a new magnitude!

The experiment continued.

Although the black box blocked everyone's view, it didn't stop anything.

Some things don't need to be seen intuitively, and intuitive data is more reliable than everything.

The container filled with concentrated sulfuric acid was removed from the black box, and the researcher in charge of measuring the irradiation damage and the neutron amplification rate immediately performed a detailed analysis of the collected data.

Standing next to the researcher, Lu Zhou quietly waited for the results of the experiment.

About half an hour passed like this.

Finally, the results are in.

"The observations are in!" A strong look of joy appeared on his face, and the researcher quickly handed the completed experiment report to Lu Zhou's hand, and made a report with an excited face, "By detecting the radiation damage on the surface of the neutron shielding material, there is enough evidence that there is 2.5 MeV neutrons on the surface of the surface during the test period...... The neutron growth rate is estimated to be 1.7%! ”

"Confirm that the fusion reaction has occurred!"

The moment they heard this, everyone in the laboratory had excited expressions on their faces, and they almost didn't cheer.

Sheng Xianfu, in particular, clenched his fists excitedly.

This experimental idea works!

There is no more exciting news for him.

Of course, although the results of the experiment are promising, the experiment itself is not optimistic in terms of the neutron amplification data.

From previous experiments, they have at best observed signs of fusion reactions, and they are still far from using this device to carry out stable and controlled fusion reactions.

Staring at the data on the experimental report, Professor Li Changxia said with a solemn expression: "The neutron amplification rate is still too low, and we want to maintain the stable operation of controlled fusion...... This level of sound waves may not be enough. ”

Lu Zhou nodded in agreement and said, "You're right, judging from the current conditions, it is difficult to achieve a stable and controllable fusion reaction. And to do that, we have to change the working fluid. ”

Prof. Changxia Lee: "What kind of working fluid are you going to try?" ”

Lu Zhou shook his head: "I don't know, but I have a possible idea." ”

"Ideas?"

"Yes," Lu Zhou nodded, "since traditional liquids at room temperature can't meet the requirements, why don't we try liquid metal?" Liquid lithium, for example, I think it's a worthwhile option......"