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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External Radiation


The external radiation (hazard) exists where an absorber (typically a person) is being exposed to a source of Ionising Radiation external to the body. Examples would include exposures to Sealed Sources, dental X-Rays and Cosmic Rays. One feature of this hazard is that moving the absorber away from the source (usually) results in a reduction in the Dose of ionising radiation to that absorber, which is not the case for Internal Radiation hazards.

Two things are infinite: the universe and human stupidity; and I'm not sure about the universe

– Albert Einstein