Gamma Rays

Gamma (γ) rays, one of the three types of rays emitted by radioactive substances [see Radioactivity, Alpha (α) rays, Beta (β) rays]. By their nature, γ-rays are identical to X-rays but possess a much shorter wavelength. The ethereal origin of γ-rays and their similarity to X-rays were proven by experiments with diffraction during the passage of γ-rays through crystals. Gamma rays exert the following effects: 1) they ionize the air and gases through which they pass, 2) they act upon a photographic plate, 3) they cause fluorescence in a number of substances, 4) they exert a biological effect. The chemical reaction that arises when substances are illuminated by γ-rays also explains their biological effect. Different cells of the organism are sensitive to the influence of γ-rays in different ways; the most sensitive are cells of an embryonic character, to which tumor cells also belong. These cells disintegrate most easily under the influence of γ-rays. The action of γ-rays, just like that of X-rays, which differ only by a longer wavelength, is used in medicine for the treatment of malignant cancerous and sarcomatous formations. Recently, due to their ability to penetrate through the thickness of metals, γ-rays have been used for the examination of metals according to the Laue method. The industrial method of using γ-rays is based on this. For details on the properties of γ-rays, see textbooks on radiology.