Though often overshadowed by its own accomplishments, materials science has played a significant role in some of modern society’s greatest advancements. From developing high-temperature super conductors to testing the strength of airplane wings to piloting the latest projects in alternative fuel, materials science has helped us understand much of our world at the atomic level.
To investigate these atomic-scale structures and dynamics, many scientists have turned to neutron scattering experiments—the process of measuring the irregular dispersal of free neutrons by matter. Utilizing a spallation neutron source to produce and direct an intense beam of neutrons at the material under investigation, the experimental technique acts in compliment to X-rays and electron microscopy, penetrating deep into a material before scattering and diffracting into unique pattern arrays. These patterns offer research scientists a window into new physics while exploring new materials and their functionality.
Neutron scattering is conducted in highly-specialized testing facilities. While a majority of these facilities have operated in Europe and the United States over the last half century, the Chinese Spallation Neutron Source (CSNS), a multi-million-dollar research center in Dongguan, China, opened its doors in 2018. The facility features a small-angle neutron spectrometer, a neutron scattering instrument that plays a key role in not only material sciences, but biological sciences, chemical sciences and physics as well, ushering in a new era of cutting-edge scientific research.
“One of the highlights of the CSNS project was hosting the SANS team from the Chinese Academy of Science to witness the position resolution testing,” says Spencer B. Neyland, Vice President of Operations at LND, Inc. “The demands of manufacturing and delivering highly specialized detectors like the LND 25020 position sensitive neutron detector bring together all the expertise and experience of LND’s 55 years in business.”
Small-angle neutron spectrometers work by directing a beam of neutrons at a sample—whether solid, crystal, aqueous or a powder— within a vacuum chamber, measuring the reactions and refractions, or changes of angle, of those neutrons as they pass through the material. In the case of the small-angle neutron spectrometer at CSNS, those measurements are taken by collecting scattered neutrons in two 1-meter by 1-meter arrays of neutron detectors. Each array consists of 120 position-sensitive neutron detectors—precisely-engineered 1-meter length by 8-millimeter diameter rods filled with neutron-sensitive He-3 and equipped with a delicate high-resistance anode.
The data collected from these pencil-thin tubes creates a map for researchers to continue their research, providing essential insight into not only the structure of materials, but how they will function and ultimately perform or react in certain conditions. In this vein, neutron scattering has played an important role in optimizing lithium batteries as well as understanding the strain on materials found in airplane wings and train wheels.
Its ability to understand the magnetic interactions of electrons has increased our understanding of magnetism, leading to product development in everything from ear buds to portable speakers. The technique can even help date and place ancient artifacts without imposing harm.
Neutron scattering data is also aiding the search for effective alternative fuel sources. Hydrogen has high potential to be a clean energy for transportation, but it is also quite volatile and hard to store for vehicular use. Because the element has the largest neutron scattering interaction of any element on the periodic table, research scientists have looked to neutron scattering to find effective means for both storing and using the fuel in the future.
As the demand for material sciences increases on an international scale, CSNS represents the next big push in neutron spectrometry. The facility hopes to offer its technical services to scientists and researchers from around the globe, and has already expressed interest in a second expansion phase to position itself among the world leaders in neutron studies.