X-ray

Description

High energy radiation with very short wavelengths (0.001 - 10 nm). X-rays were accidentally discovered by W. Roentgen in 1895. They can pass through many solids, ionize gases, and expose photographic film. The depth of penetration of x-rays through a material depends on its density. A common use of x-rays in museums is to photograph density variations in composite materials, i.e. to examine painting pigments and sculpture structures. Radiographs for paper and other low density materials are collected with soft x-rays. These are very low energy, long wavelength x-rays produced by an x-ray tube set below 15 kilovolts. X-rays are used in analytical equipment (see x-ray diffraction and x-ray fluorescence) for the determination of molecular and elemental compositions.

Synonyms and Related Terms

x-rays; xray; x-radiation, Roentgen ray

Hazards and Safety

Overexposure or cumulative exposure can damage or destroy cells and tissue structures.

Authority

• G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971

• G.G. Hawley, The Condensed Chemical Dictionary, Reinhold Publishing, New York, 6th ed., 1961

• Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000