X-radiation

Name:
X-radiation
Detailed information:
(Roentgen rays; x rays). Electromagnetic radiation of extremely short wavelength (0.06–120 Å), emitted as the result of electron transitions in the inner orbits of heavy atoms bombarded by cathode rays in a vacuum tube. Those of the shortest wavelength have the highest intensity and are called “hard” X rays. X-radiation was discovered by Roentgen in 1898. Its properties are (1) penetration of solids of moderate density, such as human tissue but retardation by bone, barium sulfate, lead, and other dense materials. (2) Action on photographic plates and fluorescent screens. (3) Ionization of the gases through which they pass. (4) Ability to damage or destroy diseased tissue; there is also a cumulative deleterious effect on healthy tissue.

Hazard:

Overexposure can permanently damage cells and tissue structures; effect is cumulative.

Use:

Spectrometry; structure determination of molecules, cancer therapy, diagnostic medicine, nondestructive testing of metals, identification of original paintings, preservation of foods.

See Radiation, Ionizing; diffraction; Roentgen.