Recently, scientists have succeeded in focusing their laser light on the intensity of one billion times the intensity of the sun's surface and achieving precise collisions with high-energy electrons, validating the key theory that electrodynamics has never been validated for nearly a century: high-order multiphoton Thomson scattering theory. The result will open the door to experiment in the theoretical system of quantum electrodynamics. During the experiment, a very high-energy directional gamma ray was generated and could be used to generate high-energy and high-intensity light sources. The process is also expected to produce gamma-ray at the second order in the laboratory, turn on the second-order nuclear physics, And other new research areas.
By focusing super-fast laser light, researchers have achieved extremely strong light fields with peak intensities one billion times higher than the solar surface. They found that with such a powerful laser, electrons moving at near-light speeds could "simultaneously" absorb thousands of photons at once and then "merge" into a high-energy photon emission, scientifically termed "higher order multiphoton Thomson scattering. " This theory was one of the well-known theories of classical electrodynamics and was proposed as early as the early nineteenth century. Due to the limitations of experimental conditions, the experimental verification of this theory was not realized until recently by the development of ultra-fast super-laser technology. Although the reported laser intensities of the latest experiments are already high, classical electrodynamics theory will no longer be applicable if the laser intensity continues to increase, replaced by quantum electrodynamics. The theory shows that when the astronomy laser pointer is strong at a thousand trillion times the sun's intensity, the laser will produce positive and negative electron pairs in the absolute vacuum, that is, to achieve Einstein's ultimate theoretical energy conversion E = mc2. The experimental result is an important experimental verification of the development of classical electrodynamics theory of quantum electrodynamics.
The experiment is extremely challenging and extremely demanding on space-time accuracy. In order to achieve collision scattering of electrons and photons, we first divide the Diocleans laser beam into two beams. One of the laser pulses is used to generate the energetic electrons with the relativistic velocity motion, that is, the laser coda electron acceleration. In this process, how to achieve stable laser acceleration itself is a challenging task. In recent years, many major international laboratories have carried out relevant research. At the same time as generating a high-energy electron beam of a size of one-eightth of the diameter of a hair filament, the other laser beam is precisely focused to the same size as the electron beam and the electron beam and the electron beam are irradiated in the micrometer space and the femtosecond time scale Precise head-on collision of the laser beam. As both electrons and photons move at the speed of light, it is a constant challenge in this area to experimentally achieve such a precise collision. Despite the fact that dozens of ultra-high-power lasers in the world are already on the order of magnitude, it is the first time that such an ultra-high-intensity experiment has been done.
Our technology can be used to generate extremely bright X-ray gamma light sources with comparable brightness to third-generation synchrotron radiation sources, but the device's volume is only a few dozen or even one percent and is expected to be replenished in the future Synchrotron radiation source provides a cheaper light source for medical imaging, material research, biological macromolecule research and three-dimensional metrology, and solves the problems of few existing synchrotron light sources, difficult scheduling and high cost. At the same time, high-energy gamma rays can penetrate the extremely thick steel plate and are expected to greatly help customs to detect drug smuggling. Due to the small size of our installations, it is possible to integrate into small container trucks in the future, further increasing the flexibility of using radiation sources.
The whole physical process of multiphoton Thomson scattering also has a very high value of basic scientific research. As a result of this physical process, multiple photons participate in an interaction event, showing a completely different calibration rule than single-photon Thomson scattering. Under superconducting laser conditions, electrons undergo extreme nonlinear motion with high photon densities so that a single electron interacts with hundreds of photons that are coherently coupled together at the same time to form an ultra-high-energy photon . In fact, the theory shows that in our experiments, up to 1,300 photons may have been already scattered at the same time. Multiphoton Thomson scattering theory has existed for decades, but has never been thoroughly verified by experiments. This is the first time that the laboratory has achieved so many photon co-participation in Thomson scattering and has completely verified the theory. The electrokinetic Development of great significance. In addition, the peak intensity of the superlaser at the focal point is estimated after various parameters are measured under the conditions of the low-energy laser pulse. At present, there is no direct measurement method. Due to the unique spatial distribution of the gamma ray generated by the interaction in this experiment and the distribution is directly related to the intensity of the colliding laser, the super gamma can be accurately calibrated according to the properties of the gamma rays generated during the experiment The peak intensity of the laser, which is currently the only way to directly measure the intensity of super-strong laser.
The researchers said that the future will further upgrade the laser, the theory of multiphoton scattering more in-depth study and expand the preliminary study of quantum electrodynamics. In addition, we will optimize the quality of gamma ray light source and hope to realize its extensive application value as soon as possible.