Radiation flux

Radiation flux is a measure of the amount of radiation received by an object from a given source. This can be any type of radiation, including electromagnetic, sound, and particles from a radioactive source.

Φ = ⁄_4πr is the radiation flux, L is the luminosity, or total power output of the source, and r is the distance from the radiation source. The units of radiation flux are W·m, or kg·s.