A gamma ray (γ) is a form of electromagnetic radiation with a very short wavelength that is emitted during radioactive decay, usually when a nucleus releases excess energy. Unlike alpha and beta particles, a gamma ray carries no charge and no mass, and it is the most penetrating of the common forms of radiation. Gamma rays often accompany alpha or beta emission as the new nucleus settles to a lower energy.

γ 射线(伽马射线)是放射性衰变中放出的波长极短的电磁辐射,通常在原子核释放多余能量时产生。与 α 和 β 粒子不同,γ 射线不带电荷也无质量,是常见辐射形式中穿透力最强的。γ 射线常伴随 α 或 β 衰变出现,因为新生成的原子核会降至较低能量。