The key laboratory of strong field laser physics of Shanghai Institute of Optics and Fine Mechanics(SIOM), Chinese Academy of Sciences (CAS), announced that they had successfully produced the anti matter--- ultra-fast positron source by ultra-intense and ultra-short laser. It immediately triggered a widespread attention at home and abroad after reported. The research finding is also published in the Plasma Physics of International Journal. Anti matter, which makes people feel more abstract, is no longer just to be seen in the science fiction movies. Actually early in 2011, China and the United States scientists had cooperated and created the anti-helium 4, namely, anti alpha particles, it is heaviest anti matter thus far. Therefore, this study also established an important milestone for the human exploration of anti matter. To have heard so much about the anti matter news, we may feel that it’s so high-end but can’t help feel confuse too. What is anti matter? What does it do? And what is the ultra-intense and ultra-short laser?

 

What is anti matter?

 

We all know that the world has microscopic existence, all of the substances are basically composed of protons, neutrons, electrons, and so on. And most has its opposite existence, anti matter is the opposite existence of the substance, that is, the positron. It is formed by the anti particles, both will be combined with their opposite substances, then liberating the high-energy gamma rays and photon in the annihilation process. Its energy liberating in the annihilation process is far more than nuclear fusion energy, so the anti matter research is always the top issue all over the world. Ultra-fast positron source is one of the anti matters, it is obtained by the ultra-intense and ultra-short laser, which is manufactured of using femtosecond petawatt laser device by Chinese scientists. It can be well applied in the medical field such as the treatment of cancer, industrial areas such as testing material, as well as the field of high energy physics, this also means that ultra-fast positron source will play an important role in the research of Electron Positron Collider driven by laser. But when the anti matter was produced by the interaction of femtosecond petawatt laser device and high pressure gas target, it would release a lot of gamma ray. Therefore, in commonly, the tungsten alloy shielding would be set in peripheral of the device. Its high density characteristic makes it have high radiation shielding effectiveness, which can well prevent the radiation generated by the laser.

 

What is the role of anti matter?

 

Firstly, the biggest role is that to detect the material flaw, namely to use ultra-intense and ultra-short laser to produce the anti matter interior the materials, then relying on the gamma rays produced by anti matter in annihilation process to nondestructively detect the internal situations of materials, i.e., to see whether it is defective or damaged. Secondly, the high-energy produced by the annihilation of anti matter and interior substances can provide significant clean energy for mankind so as to change the current status quo of the Earth's energy shortage. Finally, with the development of scientific research and technology, the role of anti matter is not just limited to the inevitable, it can also be used to ascertain the mysteries of the universe, to study of new physical phenomena or to discovery of new physical phenomena, these are worth to be seen.

 

What is the ultra-intense and ultra-short laser?

 

We all know that when acting under the same circumstances, the shorter the time uses, the greater the power will be, so the energy thus produced will also be greater. The equipment that Chinese scientists used for successfully producing anti matter is the ultra-intense and ultra-short laser. What so-called ultra-short laser device is an ultra-high-power laser device, which refers to the strong high-energy and high-intensity. the ultra-short means short time, that is femtosecond Petawatt. Femtosecond (fs) is a unit of measurement of time. What is the idea? In simple terms, one second=10¹⁵ fs, this means that this ultra-intense and ultra-short laser reaches the femtosecond level, which is equivalent to produce 1,000 trillions watts of power. This is undoubted that it would have huge contribution to high-energy physics research and nuclear research, for nuclear fusion controlling and laser weapons manufacturing. Although the great scientific and technological progress of producing anti matter by ultra-intense and ultra-short laser will play a huge role in the future and be benefit of mankind, but for now it seems that the cost of institute, is undoubtedly enormous.