The basis: neutrons and positrons
The basis of the innovative work carried out at the RID is the use of neutrons and positrons to examine all kinds of materials “from the inside out”, or to develop new materials such as radioisotopes and nuclear medicines.
Neutrons are minuscule particles normally found only in atomic nuclei. They have no electric charge and so are able to penetrate deep inside materials. Here, by interacting with the host material, they change their direction and speed. And by measuring those changes, we can learn more about the material.
Neutrons behave a bit like revolving compass needles. In the professional jargon, we say that they have “magnetic moment” and “spin”. If they pass through a magnetic field, their orientation changes. Measuring that reveals the magnetic structure of a material.
Positrons are the antiparticles of electrons: they have the same mass, but the opposite electrical charge. This means that when positrons and electrons collide, they annihilate each other. All that remains is high-energy radiation, which researchers at the RID study to glean information about the materials involved. This helps them better understand such phenomena as metal fatigue, and to improve the electrical efficiency of devices like solar cells.