Beta radiation is the emission of electrons or positrons during the radioactive decay process or during a nuclear reaction. Beta radiation has an energy continuum. The maximum energy Eßmax is always quoted, e.g. for P-32 decay this is 1.7 MeV. Beta radiation is easily absorbed by thin layers (e.g. plastic or 1 cm aluminium).

Diagram beta radiation

Energy distribution of the electrons (ß- particles) emitted during the ß- decay of P-32.