The China Spallation Neutron Source (CSNS), located in Dongguan City, south China’s Guangdong Province, began a new round of user operation Thursday, with 57 experiments on new materials to be conducted in the next four months.
These experiment proposals, including one applied by a foreign user and five from Hong Kong and Macao users, mainly involve magnetic materials, quantum materials, lithium battery materials, shale, catalytic materials, high-strength steel and high-performance alloys, said Prof. Zhang Junrong of the Institute of High Energy Physics (IHEP) under the Chinese Academy of Sciences (CAS).
Construction of the CSNS project started in 2011 under the direction of the IHEP, with a total investment of 2.3 billion yuan (323 million U.S. dollars).
It was put into use in August 2018, consisting of a linear accelerator, a rapid cycling synchrotron, a target station, three neutron instruments and other auxiliary facilities.
PROBING INTO THE MICROWORLD
Dubbed as a “super microscope,” a spallation neutron source can produce and accelerate protons before smashing them into the target to produce neutrons, and the neutron beams will be directed to hit material samples. Researchers can thus accurately infer the atomic structure of the materials by measuring the distribution of scattered neutrons and their changes in energy and momentum.
But unlike an X-ray from a synchrotron radiation facility, which is also used to explore the microstructure of materials, neutrons are not sensitive to the number of electrons and are a better “probe” when studying materials containing light elements with fewer electrons, such as carbon, hydrogen and oxygen.
Jin Dapeng, deputy director of the IHEP Dongguan Branch, gave an example in the field of energy materials. Hydrogen-powered vehicles are more energy-efficient and environmentally friendly than gasoline-fueled alternatives. Scientists hope to store hydrogen in a denser solid form, but pressurizing hydrogen can easily trigger explosions. So researchers are trying to develop a metal-organic framework that can intake hydrogen for storage and release it when it is needed. Neutron scattering can help scientists study where and under what conditions hydrogen is better stored and released in this material.
Benefiting from the advantages of neutrons in examining light elements, the CSNS’s first batch of three neutron instruments for scientific experiments have achieved fruitful research results during the first two rounds of user operation.