Beta particles are highly energetic and fast electrons or positrons that are emitted by certain types of radioactive nuclei. Beta particles that are emitted are a form of ionizing radiation known as beta rays. There are two forms of beta particles, ß+ or ß-, depending on if it is a positron or electron respectively.
ß- Decay or electron emission, is an unstable atomic nucleus with an excess of neutrons where the neutrons are converted into a proton, an electron and an electron-type antineutrino. Below is the process by the weak interaction.
n → p + e− + νe
Beta decay mostly occurs with neutron-rich fission by products produced in nuclear reactors. Free neutrons will also decay by this process.
ß+ Decay or positron emission is an unstable atomic nucleus with an excess of protons where protons are converted into neutrons, a positron and an electron-type neutrino. Below is the process.
p → n + e+ + νe
Beta plus decay will only happen inside a nucleus when the absolute value of the binding energy of the daughter nucleus is greater than that of the mother’s nucleus. Therefore the daughter nucleus is a lower energy state.
Beta particles are used to treat many health conditions such as eye and bone cancers. Beta particles are also used in quality control testing of thickness of materials. They are also used in positron emission tomography, PET scans.