(GM counter or GM tube) The Geiger-Mueller counter is a radiation measuring instrument. A Geiger-Mueller detector consists of a gas-filled tube that discharges electrically when ionizing radiation passes through it. A counter records the events.

An irradiating apparatus is capable to produce ionizing radiation or to accelerate atomic particles.

A lead apron is a shield of lead and rubber, used to protect patients and staff. This apron protects the reproductive and other vital body organs against high exposure of ionizing radiation.

(LET) Linear energy transfer is the ratio of energy transferred by an ionizing radiation traveling through a material per unit path length. LET depends on the kind of radiation, the density of the material, etc.
The higher the LET, the higher the biological damage through energy deposition along the particle track.

Neutron radiation is one type of ionizing radiation. Neutrons get emitted from an atom by the fission process or by decay processes. In the upper atmosphere neutron radiation is produced by the interaction of cosmic radiation with air. Neutron radiation is used for the production of medical isotopes and certain direct medical therapies.

See also Neutron Activation, Neutron Activation Analysis and Neutron Capture.