NCIt definition : High-energy, short wavelength, ionizing electromagnetic radiation emitted from the
nucleus. Gamma radiation frequently accompanies alpha and beta emissions and always
accompanies fission. Gamma rays are very penetrating and are best stopped or shielded
by dense materials, such as lead or depleted uranium. Gamma rays are identical to
x-rays and are only differentiated by their origin. (from NRC Glossary);
Alternative definition : NCI-GLOSS: A type of high-energy radiation that is different from an x-ray.; CDISC: A high-energy, short wavelength (shorter than X-ray), ionizing electromagnetic
type of radiation emitted from the nucleus.;