Radiation Protection Glossary

A radiation protection glossary for Radiation Protection Supervisors (RPS) and anyone interesting in radiation safety terminology. The glossary is a mixture of health physics terms, and phrases related to radiation legislation, transport, practical safety and similar.

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Beta Particle

The beta particle has the form of a high speed negatively charged electron (or a positively charged electron in the case of the positron). In beta decay (electron emission) a neutron in the nucleus is converted to a proton with the release of a high speed electron and an anti neutrino. For example, C-14 decays to N-14 and the atomic number has increased by one whilst the mass number at 14 is unchanged. The beta particle is more penetrating than alpha particles but still much less so than gamma rays or x-rays. For every beta emitter there is a unique energy spectrum characterised by average and maximum beta energy. For Tritium (H-3) this is around 18.5 KeV, for C-14 its 156 KeV and for P-32 it is about 1.7 MeV.

The definition of 'safe' is not strictly an engineering term; it's a societal term. Does it mean absolutely no loss of life? Does it mean absolutely no contamination with radiation? What exactly does 'safe' mean?

– Henry Petroski