Ionizing radiation is radiation that carries energy sufficient to cause electrons in atoms or molecules of matter to become free, thereby causing ionization of those atoms or molecules, at wavelengths of less than 100 nm, and includes cosmic rays, X-rays, and radiation from radioactive materials.
Ionizing radiation whose wavelength is short enough and energy high enough to ionize atoms or molecules in a substance, i.e., to remove one or more electrons from an atom or molecule to form a positive ion. Ionizing radiation includes X-rays, gamma rays, ultraviolet rays, and so on.
There are many sources of ionizing radiation, including natural and artificial sources of radiation. Natural sources of radiation come mainly from radioactive elements within the earth, such as potassium, uranium, thorium, etc., and cosmic rays from space.
Artificial sources of radiation include medical equipment, industrial testing equipment, and nuclear facilities. The dosage unit of ionizing radiation is the Sievert (Sv), and its radiation effect is proportional to the radiation dose, i.e., the larger the radiation dose, the more pronounced the radiation effect.
Characteristics of Ionizing Radiation:
1, high energy and ionizing power: The most significant feature of ionizing radiation is the high energy it carries, which is sufficient to knock the electrons out of material atoms or molecules, leading to the phenomenon of ionization. Ionization is the state in which otherwise stable atoms or molecules change into ions as a result of losing or gaining electrons. This property allows ionizing radiation to significantly alter the chemical and physical properties of matter when it interacts with it.
2, short wavelength and high frequency: ionizing radiation usually has a very short wavelength and very high frequency. According to the electromagnetic spectrum, the wavelength of ionizing radiation is less than 100 nanometers, which includes X-rays and gamma rays and other high-energy electromagnetic radiation. The short wavelengths and high frequencies mean that particles or quanta of ionizing radiation have high speeds of motion and momentum, and are able to penetrate many ordinary substances, even metals.
Reference: Baidu Encyclopedia - Ionizing Radiation