ionizing radiation exposure gamma ray exposure The condition of being subjected to high frequency, high energy electromagnetic radiation, that is, energy emitted and absorbed by charged particles, which exhibits wave-like behavior as it travels and has both electric and magnetic field components. Gamma radiation is traditionally considered to have wavelengths less than 0.01 nm and are generally emitted by nuclei rather than by electrons. XCO:0000040 experimental_condition_ontology gamma radiation exposure