Radiation Protection Glossary

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

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For formal advice, see our Radiation Protection Adviser pages. 


A general term applied to parts of instruments which are designed to detect Ionising Radiation. Ionising radiations interact with the detector, the detector converts this interaction into a signal which can be amplified and interpreted by other devices. Detectors can be Passive Detectors (which require a subsequent process, e.g. chemical etching, to determine useful information), and Active Detectors (which enable real time information to be obtained, e.g. EPD).

In the beginning, there was nothing, which exploded

– Terry Pratchett -