beta particle - β− decay (electron emission), β+ decay (positron emission), Uses

A charged particle emitted in beta decay. It is usually a high-energy electron, but positrons are also sometimes called beta particles. These particles are emitted with a wide range of energies from any particular source; the typical particle range in air is several metres.

The beta particles emitted are a form of ionizing radiation also known as beta rays. The production of beta particles is termed beta decay.

There are two forms of beta decay, β, which respectively give rise to the electron and the positron.

β− decay (electron emission)

Unstable atomic nuclei with an excess of neutrons may undergo β− decay, where a neutron is converted into a proton, an electron and an electron-type antineutrino (the antiparticle of the neutrino):

This process is mediated by the weak interaction. The neutron turns into a proton through the emission of a virtual W emission turns a down-type quark into an up-type quark, turning a neutron (one up quark and two down quarks) into a proton (two up quarks and one down quark).

Beta decay commonly occurs among the neutron-rich fission byproducts produced in nuclear reactors.

β+ decay (positron emission)

Unstable atomic nuclei with an excess of Inverse beta decay is a key step in the fusion processes that produce energy inside the sun.

Uses

Beta particles can be used to treat health conditions such as eye and bone cancer, and are also used as tracers.

Inverse beta decay of a radioactive tracer isotope is the source of the positrons used in positron emission tomography.