China Spallation Neutron Source in Dongguan, south China’s Guangdong Province.（PHOTO:XINHUA）

By TANG Zhexiao

The China Spallation Neutron Source (CSNS) put into use in August 2018, is the nation's first research facility providing the most intense pulsed neutron beams for 345 scientific research projects. More than 90 percent of the equipment of CSNS is based on independent research and domestically produced.

Neutrons are small particles with no charge. By examining the route of the neutrons via a spectrometer, researchers can deduce the internal structure of the material, thus conducting scientific research in fields of life science, material science and new energy.

As one of the largest scientific and technological facility projects in China, CSNS is expected to make a contribution to many areas of scientific research and applications.

Probing microworld through super microscope

Considered as a "super microscope," a spallation neutron source can probe the microscopic world. But unlike X -rays, neutrons are not sensitive to the number of electrons and are easier to probe when materials containing light elements with fewer electrons, such as carbon, hydrogen and oxygen, are studied.

Chen Hesheng, the CSNS project manager and director of the Institute of High Energy Physics (IHEP) at the Chinese Academy of Sciences, explained neutron scattering technology as marbles shot at a net and bouncing off it at different angles. If the movement path of these marbles is recorded, then the shape and material of the net can be deduced. The more marbles are used, the more accurate the net calculations will be.

However, is the facility safe from radiation? Chen Hesheng said that CSNS's power comes from electricity. "According to test results, the amount of radiation received by residents who live near the spallation neutron source for one year is equivalent to taking a long-haul flight," said Chen.

Challenges of first neutron beam output

Obtaining spallation neutrons can be technically complex and expensive. CSNS is the world's fourth spallation neutron source. The other three are in Britain, the U.S. and Japan.

Construction of the CSNS project in China started in 2011, under the direction of IHEP, with a total budget of 2.3 billion RMB. To build China's first spallation neutron source facility, the CSNS team took up the challenge with an efficient approach.

Chen, who has undergone heart surgeries before, was nevertheless on hand to lead his team through the technological and engineering difficulties.

CSNS successfully made their target and the first neutron beam was realized in 2017. The world's fourth pulsed spallation neutron source declared a success.

CSNS's advanced research platform

The "super microscope" is ideal for studying the microstructure of materials and can be used for research in high-speed trains and aircraft, tumor radiotherapy research and green energy development of flammable ice, according to Chen.

Since its official operation, CSNS has served more than 2,600 users worldwide and completed more than 500 scientific projects, including new lithium-ion battery material structures and solar cells, and also launched preliminary research in fields of aviation materials, flammable ice, shale gas and catalysts.

The construction of CSNS will also strengthen the international exchanges and cooperation between the domestic neutron scattering science and application circles, and provide a good opportunity for neutron scattering technology and applications.

Currently, CSNS is planning a second phase of construction and upgrades, aiming to accelerate its output to five times its current ability, and providing a more advanced research platform for frontier scientific research, national needs and economic development.