How to catch a neutron

Neutron researchers work on the leading edge of physics and material sciences. From imaging systems, so fine they can define the structure of a protein molecule, to constructing better body armor, to improving energy storage, neutron research has made many advances and breakthroughs possible.

Harnessing the power of neutrons, however, requires that they are controlled, and that is challenging. A group of neutrons, produced in a neutron generator, would tend to fly in every direction at once. And because they are so small, they can penetrate walls, metal, and just about everything else, until they bounce off a particle and shoot in another direction.

Controlling neutrons requires a neutron guide, sometimes called a neutron channel. SwissNeutronics, one of the world’s leading suppliers of instruments used in neutron research, – has relied on SCHOTT BOROFLOAT glass for many years and recently made an entrance into the Chinese market, developing a neutron guide for the Institute of High Energy Physics in Dongguan, near Hong Kong.

What makes BOROFLOAT particularly suited for this highly specialized field is a combination of its physical properties.

Neutrons can only be guided into channels if they reflect off its surface at very shallow angles. This requires a material so smooth that individual atoms can’t project from the surface of the guide. BOROFLOAT glass provides such pristine surfaces and is made utilizing a highly sophisticated production process where molten borosilicate glass floats on top of a bath of liquid tin and cools down in an extremely controlled environment. The result is an exceptionally smooth, flat glass with uniform thickness.

SwissNeutronics then coats BOROFLOAT with 10,000 nano-thin layers of reflective material. The mirror-coated BOROFLOAT panels feature a roughness of less than one nanometer. Anything higher would cause neutrons to bounce out of the material.

In addition to its surface quality, BOROFLOAT also features high chemical durability, excellent mechanical strength, and a low coefficient of thermal expansion, which prevents it from changing shape when subjected to temperature swings. And the high boron content in the formula acts as an excellent shield against neutron radiation.

SwissNeutronics has relied on SCHOTT BOROFLOAT glass since 1999, and the results have led to huge improvements in scientific instrumentation. One neutron guide built by the firm for a lab in Russia resulted in a higher neutron yield by a factor of six. Experiments that typically took days to complete can now be finished in hours.

Neutrons are particularly useful in the study of materials. For example, they can be used to detect hidden stresses in the parts used to build bridges. Because they don’t have a charge, neutrons are particularly sensitive to hydrogen, making them well suited for fuel cell research. Neutron research can also lead to reduction in pollution from smokestacks and allowed for the development of smaller needles for injections.

Those commercial applications, however, are just part of the equation. Neutron research labs help scientists learn new things about the nature of our physical universe. In order to do so, researchers need highly precise equipment made with quality materials to uncover all the insights neutrons have to share.

• More about SCHOTT BOROFLOAT