Positron Emission (Beta+ Decay)

Positron emission is a type of beta decay, sometimes referred to as "beta plus". In beta plus decay, a proton is converted to a neutron via the weak nuclear force and a beta plus particle (a positron) and a neutrino are emitted. Isotopes which emit positrons include Carbon-11, Nitrogen-13, Oxygen-15 and Fluorine-18; for example:

These isotopes are used in positron emission tomography, a technique used for medical imaging.

Electron capture is a competing decay mode in this process and is energetically favoured, but as the energy difference goes up so does the branching ratio towards positron emission.

See Also

Electron Emission (Beta- decay).