Electromagnetic radiation of very short wavelength, lying within the wavelength interval of 0.1 to 1.5 angstroms (between gamma rays and ultraviolet radiation). X-rays penetrate various thicknesses of all solids, and they act on photographic plates in the same manner as light. Secondary x-rays are produced whenever x-rays are absorbed by a substance. In the case of absorption by a gas, this results in ionization.
Commonly known as Yagi antenna. A type of directional antenna used on some types of radar and radio equipment consisting of an array of elemental, single-wire dipole antennas and reflectors. Invented in 1926 by Shintaro Uda and Hidetsugu Yagi of Tohoku University, Japan.