Wei Feng grabbed his hair and thought about how to solve the problem of out-of-phase in the acceleration of the laser tail field.

At present, there is nothing to study in high-energy physics of low-level particle colliders, because most of the results have been figured out by everyone.

If high-energy physics is to take it to the next level, the collider needs to have at least ∨ of electron energy on the order of Te.

Since the ability of laser tail field acceleration is 100 GeV/m, isn't it enough to accelerate by 10 m? One of the most important constraints is the loss of phase.

The phase is the phase of the phase, and the plasma wave of this wake wave can be regarded as an approximate sinusoidal function, then in a y period, the first half of the cycle is positive for the electric field strength and decelerates for the center, and the second half of the period is negative for the electron.

Therefore, the electrons should be confined to the acceleration phase of the second half of the cycle.

But the problem is that the laser propagates in the plasma, and the speed cannot reach the speed of light due to dispersion, so the speed of the wake wave cannot reach the speed of light.

However, the electrons at the GeV level are very close to the speed of light (the relativistic factor gamma is about 2000), so there is a relative velocity between the electron and the wake wave.

The length of the phase loss is also on the order of mm to cm, which is why it can only accelerate to the order of GeV at present. Thus the out-of-phase limits the maximum electron energy.

Huang Mingzhe suddenly said: "If you want to achieve the electron energy of TeV, you can only find another way at present. ”

"Going off the beaten path? Do you have an idea?"

"If one acceleration is not enough, then add a few more times."

Wei Feng thought about it, and his eyes lit up suddenly, but then he shook his head again: "No, if you do this, what is the difference between the tail field acceleration and the traditional accelerator?"

“……”

Huang Mingzhe immediately understood what Wei Feng meant, and the multi-stage joint acceleration scheme he proposed could reach 10GeV even if the single-stage acceleration could reach 10GeV.

To achieve the target TeV-class collider, then the equipment will be very huge, the cost will be greatly increased, and the advantages compared with traditional accelerators will basically not be reflected.

And not to mention the 100 level, at present, it can be achieved at most two levels, and the energy of acceleration is at the 100 MeV energy level, which is pitifully small compared to the goal of 1 TeV.

The reason for this is that it is so difficult, and multiple laser tail field acceleration stages need to be precisely matched on the time and space scales of femtoseconds and microns.

The speed of high-energy electrons is basically very close to the speed of light, and the speed of laser propagation in the plasma is required to be the speed of light without losing phase.

And plasma is a dispersive medium, how is it possible to achieve the speed of light? Huang Mingzhe bit the tip of his pen in distress.

However, Wei Feng was inspired by Huang Mingzhe's idea, and he wrote and drew on scratch paper.

The scratch paper was like a ghost drawing, and only Wei Feng knew what it was.

"Mingzhe has some ideas, I need you to calculate."

"No problem."

Wei Feng said his thoughts, Huang Mingzhe quickly calculated his mind, he kept calculating the data, and Wei Feng kept modifying the plan.

A week later.

"That's it!"

The two of them looked at the model simulated on the computer.

The one on the right is a stepped mirror, which is composed of many rings in three dimensions, each with a different depth and not on a single plane.

In this way, the incident light is reflected to form a series of rings with different ∨ delays between the rings.

Many of these rings are then incident on the left parabolic focusing mirror, and this focusing mirror is specially designed to focus the laser beam without changing the pulse width of the laser beam.

However, the magic of this focusing lens is that it can focus light from different radial positions to different longitudinal positions.

In this way, with the stepped mirror, the light of different rings (corresponding to different time delays) can be focused to different focal positions, greatly extending the length of the focal point.

The purpose of this is to be able to make the effective velocity of the focal point the speed of light.

To put it simply, it is to focus a halo to a position and create a wake wave field to accelerate electrons to very close to the speed of light.

When the electrons are out of phase in this wake field, the light from the next ring is focused to where the electrons travel, and the time delay can be achieved by precisely adjusting the depth of the ring on the step mirror, so that the electrons enter the second wake field generated by the second ring.

By analogy, assuming that each laser ring accelerates electrons to 10 GeV, only 100 rings are needed to accelerate electrons to 1 TeV.

The calculations of the two showed that only 45 meters were needed to achieve 10 Tev electron acceleration, and 4.5 meters of acceleration distance could increase the energy level to 1 TeV.

The large particle collider of the Western Continent Alliance is designed with a maximum energy level of 7 TeV in one direction and 14 TeV in both directions.

In other words, according to the plan of Huang Mingzhe and Wei Feng, to achieve the total energy level of 14TeV, only an acceleration field with a length of 63 meters is needed.

The large particle collider of the Western Continent Alliance has a total length of 27 kilometers.

27 km and 63 meters, what is the difference? Nearly 428 times the difference, the cost is even more unthinkable.

The Xizhou Alliance has spent a total of more than 8 billion US dollars, and the annual use and maintenance cost is about 1 billion US dollars, which is terrifying to think about.

There are really few forces in this world that can afford to play with such a big toy, except for the Xizhou Alliance, which can be taken out by the countries of China, Mi, and Dongying.

As for the 100-kilometer-long super-large particle collider planned by the Institute of High Energy Physics of the Chinese Academy of Sciences, he can only say that he can just think about it.

"Mingzhe, what's going on with the laser?"

"I asked yesterday, and now I have only achieved 670J energy level, which is still a long way from the target of 3000J."

"Already achieved 670J? Our materials research institute is too powerful, isn't it?" Wei Feng didn't feel slow, but felt very fast.

"Fast? I think so-so. Huang Mingzhe said with a smile.

"Do you say that? If you say this, other people who study the material will hear it, and they may die to show it to you. Wei Feng smiled bitterly.

"Let's get ready to build a small test type and finish the paper at the same time."

“OK。”

This kind of theoretical physics, Huang Mingzhe doesn't want to hide it, after all, no matter how beautiful the pavilion in the air is, it is just a decoration without materials.

The thinking club only needs to master the core of the material, and others can only stare dryly.

With the help of more than two dozen researchers, the Institute of Physics spent more than two million yuan to complete a small experimental laser tail field accelerator, albeit with very small energy levels.

But to verify their scheme, that is more than enough, now there are no high-energy ultrashort pulses, and building a large laser tail field accelerator is also a decoration.

"Start the device."

A group of researchers were excited, and the researchers of high-energy physics who did not know that they did not expect that they could be seen in private enterprises.

"The laser input is stable."

"The laser automatic correction system is activated."

"The tail end output energy level is being calculated."

"The energy level is 4GeV."

Bang Bang Bang ...... The researchers applauded and howled.

Wei Feng and Huang Mingzhe looked at each other and smiled, obviously everything was expected by them.

"Let's be quiet and experiment a few more times." Huang Mingzhe commanded.

"Okay."

With the progress of the experiment, the prediction data of the paper and the experimental data are basically the same, and the paper is slightly revised.

The paper, titled "Acceleration of the Phase-Free Wake Field", was sent to the editorial office of Acta Physica Sinica.