Radioactive decay processes
Positron emission is a type of beta decay, referred to "beta plus"(β+ ). In beta plus decay, a proton is converted to a neutron via the weak nuclear force and a beta minus particle (a positron) and a neutrino are emitted. Example isotopes which emit positrons are C-11, N-13, O-15 and F-18. These isotopes are used in Positron emission tomography.
See also Beta decay