Shanghai Synchrotron Radiation Light Source takes pictures of molecules

Produced by: Science Popularization China

Author: Digital World

Producer: China Science Expo

Light is our friend who accompanies us day and night in the modern world. What kinds of light do you know? Sunlight? Light? In fact, there are more than these kinds of light in the universe, and their abilities are far more than just illuminating for humans.

Today, we want to talk to you about the unusual series of advanced light sources in large scientific facilities.

Red, purple, soft, hard...all kinds of light

Light allows us to see the world in front of us. We want to see farther to explore the mysteries of outer space. We want to see deeper to see the internal structure of protein.

The light that the human eye can see is called visible light. In the large family of light, visible light only accounts for a small part. Science believes that light is actually an electromagnetic wave. Due to different frequencies and wavelengths, it is divided into radio waves, microwaves, infrared, visible light, ultraviolet, soft X-rays, hard X-rays and gamma rays.

With the help of radio waves, astronomers can explore distant unknown planets, with the help of radar microwaves, soldiers can see aircraft hundreds of kilometers away, and with the help of X-rays, doctors can see through the bones and internal organs of patients.

Therefore, light is particularly important for science and technology. As you can see from the world light source map below, the world's technological powers have a relatively complete layout in the construction of different types of light source facilities. This is also true for my country.

The brighter areas are mainly located in North America, Western Europe, eastern and southern Asia and its coastal plains. The brightness is lower in Africa, Oceania and central South America.

Image credit: NASA

At present, my country's large-scale light sources include synchrotron radiation sources, free electron lasers, and ultra-intense and ultra-short lasers.

In terms of geographical distribution, light sources have been built in Shanghai, Hefei, Dalian, and the fourth-generation Beijing Light Source (High Energy Synchrotron Radiation Light Source, Huairou) is under construction, forming a good situation of coordinated layout of high-energy, medium-energy and low-energy light sources.

Synchrotron radiation source to take pictures of molecules

On the morning of June 28, 2021, on the occasion of the 100th anniversary of the founding of the Communist Party of China, the first scientific research equipment of the High Energy Synchrotron Radiation Source (HEPS), which was supported by the National Development and Reform Commission and constructed by the Institute of High Energy Physics of the Chinese Academy of Sciences, was installed. The Advanced Light Source Technology R&D and Testing Platform (PAPS), which provides technical R&D and testing support capabilities for it, was put into trial operation at the same time.

When synchrotron radiation is irradiated on matter, many different effects occur, each of which is closely related to the physical or chemical properties of the matter itself.

Therefore, by using synchrotron radiation to observe matter, we can accurately explore the internal structure of matter and the interaction between electrons within matter. Figuratively speaking, synchrotron radiation can "take pictures" of molecules.

In 2009, a world-class photon science center was built in Shanghai, which significantly promoted the rapid development of many disciplines in my country, enabled a large number of experiments that could not be carried out in China before to be conducted in China, and provided indispensable experimental conditions for many disciplines.

Shanghai Light Source

Image source: Shanghai Synchrotron Radiation Light Source

Relying on this light source, scientists have achieved a number of major results: conducting research on the Ebola virus, analyzing the structure of the H5N1 avian influenza virus, characterizing the structure of catalysts, and making breakthroughs in research on efficient methane conversion.

The strongest light in the world is in Shanghai, China

In addition, ultra-intense and ultra-short lasers are considered to be the brightest light sources known to mankind. They are the latest development frontier and key competitive area in international laser technology, and have great scientific and technological significance and application value.

For example, ultra-intense and ultra-short lasers can be used to produce antimatter and detect dark matter, study astrophysics and the origin of the universe, etc.

In October 2017, the Shanghai Ultrastrong Ultrashort Laser Experiment Facility (SULF) achieved the world's first 10 petawatt laser amplification output.

Image source: The Paper

You may have no idea what 1 petawatt is. 1 petawatt is equivalent to 500 times the average power of the global power grid. If a 10 petawatt laser is focused to 10 microns, the light intensity achieved is equivalent to 10 times that of "focusing" all the sunlight on the earth's surface onto a strand of hair.

In November 2019, the device successfully output the world's highest peak power repetition rate 12.9 petawatt laser, which was hailed as the fifth milestone since the invention of the laser. The device uses a large-size titanium sapphire crystal with a diameter of 235 mm, which was independently developed by the Chinese Academy of Sciences and is currently the world's largest known laser amplification crystal.

Well, today’s “light chasing journey” ends here. Although we stop here, scientists’ exploration in the field of optics will not stop. We look forward to more scientific research results in the future to benefit mankind.