Scatter matter – observing the world through neutrons
By : Kenix Wong
Neutron scattering is a powerful means for studying the structure and dynamics of matter, and is of immense significance to physics, materials science, biology and chemistry.
The neutron is one of the tiny particles that make up the nucleus of an atom while neutron scattering refers to the interaction between a neutron and the nucleus.
The CityU research team on neutron scattering coordinates with CSNS on professional training, research projects and facilities. “Neutron scattering research can help scientists study the structure of materials and better understand dynamics,” explains Professor Wang Xunli, Chair Professor of Physics and Head of the Department of Physics. He’s also responsible for CityU’s neutron scattering research project.
The new Joint Laboratory on Neutron Scattering at CityU is the only laboratory in Hong Kong for research into this discipline. Co-established with the Institute of High Energy Physics under the Chinese Academy of Sciences (CAS), the lab will enhance the city’s role in developing science and technology in the Greater Bay Area and will work closely with the China Spallation Neutron Source (CSNS) in Dongguan on professional training, research projects and facilities.
The new joint lab was ranked 1st among five newly added joint laboratories by CAS last year, and, located in Dongguan, CSNS is the 4th institute in the world to have such a facility.
“By measuring the change in energy and momentum of scattered neutrons, scientists can better understand the structure (atomic packing) and dynamics (atomic motion) of materials. Such research findings will make great contributions to the development of medicine, nuclear energy, nanotechnology, physics and materials science,” Professor Wang says.
Studying the structure of materials is very important to materials science since structure determines properties. Neutrons have no charge yet they have a magnetic component, which means they are particularly suitable for studying alloys, continues Professor Wang.
Professor Wang (2nd left) and his team focus on the study of neutron scattering, which is immensely significant to physics, materials science, biology and chemistry. “The bulk of our understanding of magnetic structures is determined by neutron scattering,” he adds.
To start with, scientists must produce the neutrons. The spallation neutron source is a major scientific instrument for generating neutrons. The neutron-generating process slams protons against a metal target through high-energy protons provided by accelerators. This process creates an abundance of neutrons, which are delivered to many spectrometers for measurements.
Professor Wang said the joint CityU lab will have an opportunity to build its own scattering instrument through collaboration with CSNS. Already, through sponsorship from CAS and the Croucher Foundation plus a grant from the Collaborative Research Fund under the Research Grants Council, the lab is a partner in the construction of the highly complex Multi-Physics instrument for studies into disordered materials, for example, glass and liquids, where the atomic packing appears to be irregular.
The highly complex Multi-Physics instrument under construction in partnership with CityU at CSNS in Dongguan is used for studying disordered materials.