Shanghai's super-short laser for the first time to create a "proton knife" for cancer treatment

"To make the first shot!" These days, the Shen Baifei team of the Shanghai Institute of Optics and Fine Mechanics of the Chinese Academy of Sciences gave up the high temperature holiday and tried 5 watts of the super-short laser experimental device in Shanghai (1 watt = 1 10,000) Wa) laser pulse, this is the first time the research team has experimented with such a high power laser. To this end, they fought day and night, and strive to accelerate the device to produce high-energy proton beams next week, and "hit" on samples such as tumor cell sections.

At the same time, there are many other researchers in the super-short laser experimental device building in Shanghai. They are installing and debugging equipment to ensure that 10 watts of laser pulse output is achieved by the end of this year, becoming the "world's first".

The construction of the Zhangjiang Comprehensive National Science Center is the core task of Shanghai to build a globally influential science and technology innovation center. In this research highland, many ultra-short lasers, Shanghai light sources, soft X-ray free electron lasers and other devices are under construction or operation. The world's largest photonics field large scientific facilities have emerged, concentration and display. constantly improving.

Laser "proton knife" is expected to treat cancer

The ultra-short ultra-short laser is the brightest light source known to man, and is equivalent to focusing the total solar radiation received by the Earth to the thickness of the hair. The so-called "super strong" is that the peak power of the laser pulse reaches the level of the wattage; the so-called "ultra-short" is that the pulse width reaches tens of femtoseconds (1 femtosecond = 1 billionth of a second). Lasers with such high energy can create extreme conditions in the laboratory that resemble the inner and black hole edges of stars, and are of great value in many fields of technology.
Because of this, the EU's "Extreme Light Structure Super High Field Facilities" (ELI) program has been launched to build three 10 watt laser units in three Eastern European countries. In August last year, the Shanghai Super-short laser experimental device developed by the Shanghai Institute of Optics and Mechanics of the Chinese Academy of Sciences took the lead in realizing the 5-shot laser pulse output in the world.

How strong is the brightest light source in the world? The subject led by Shen Baifei’s researcher is composed of “early adopters”. Since last week, they have been preparing for the first experiment. They plan to use the 5 watt laser device to accelerate the proton beam to tens of tens of seconds from femtosecond to picosecond (1 picosecond = 1 trillionth of a second). MeV (mega electron volts) and hit the experimental sample. "Protons are 1837 times heavier than electrons. When lasers are used to accelerate protons, they need to be "high-powered". 5 lasers can be used." Shen Baifei explained. Of course, traditional particle accelerators can also accelerate microscopic particles such as protons, but it is usually costly to build a kilometer-scale tunnel. The ultra-short-short laser device is much less expensive, and it produces a variety of high-energy beams, such as proton beams and gamma rays, whose parameters can be complementary to the beam lines of the particle accelerator.

Shen Baifei (first from left) led the team to work on the ultra-short laser experimental device in Shanghai. Shao Jianping

In the experimental samples to be shot by the proton beam, the tumor cell sections are closely related to the health of the people. At present, proton and heavy ions have achieved good clinical results in the treatment of cancer, but due to the construction of particle accelerators, the cost is quite high. The "proton knife" created by the ultra-short laser device should also achieve the effect of killing tumor cells, and is expected to significantly reduce the cost of treatment, which is undoubtedly a great gospel for the people. "I hope that the first shot we will play will lead to the laser "proton knife" in the future." Shen Baifei said.

High-energy X-ray to see the structure of the engine components

Like the ultra-strong ultra-short laser experimental device, the second phase of the Shanghai Light Source Project, the adjacent soft X-ray free electron laser test device and user device construction project are also in the heat. "Now, the area of ​​"Nautilus" is a big change." Zhao Zhentang, director of the Shanghai Institute of Applied Physics at the Chinese Academy of Sciences and director of the Shanghai Light Source Center, said with a smile.

As the earliest built Zhangjiang University scientific device, Shanghai Light Source has provided experimental machine time and corresponding services to 16,000 users, and played an active role in supporting China's basic scientific research, key technology research and development, and health incident response. From the perspective of this paper, Shanghai Light Source users published nearly 70 papers in three top international journals, Science, Nature and Cell, and published 900 papers in other high-end academic journals.

“After the completion of the second phase of Shanghai Light Source, we can study the fuel flow mechanism in the engine injector, which is expected to save 10% energy consumption for the car engine.” Wu Zhijun, a professor at Tongji University Automotive College, is full of expectations. According to reports, the internal structure and mechanism of the engine fuel nozzle determine its performance. In the past, technology developers often optimized their structures by experience; today, with the high-energy X-rays emitted by Shanghai light sources, they can see the micro-scale structure of metal parts clearly, thus designing the "optimal" structure.

As one of the first users of Shanghai Light Source, Wu Zhijun team has invented a series of controllable spray technologies after years of research and has applied for more than 10 patents. They are working with companies such as SAIC and FAW to promote the industrialization of scientific and technological achievements and apply these technologies to aero engines. What makes Wu Zhijun happy is that the fast X-ray imaging line station he proposed to build has been approved and became one of the 16 beam lines of Shanghai Light Source Phase II. When it was built and opened in 2019, it emits X-rays that are not only brighter than the first-phase line station, but also can achieve a hundred-second "instantaneous freeze" in time resolution, allowing researchers to study the fuel in the injector. Flow mechanism.

Shanghai Light Source Phase II Station, soft X-ray free electron laser test equipment and user equipment are under construction. Photo by Hu Weicheng