Andrew Lang (physicist)

Andrew Richard Lang FRS CBE (9 Feb 1924 - 30 Jun 2008) was a British scientist and crystallographer.

He was born in St Annes-on-Sea, Lancashire, UK

He was elected a Fellow of the Royal Society in 1975. His candidature read "Dr. A. R. Lang has made valuable contributions to X-ray crystallography in general, especially in original developments of instrumental method which combine economy with precision; and most notably in developing the technique of X-ray topography which is the method of choice for observing the internal imperfections of highly perfect crystals. Being applicable to specimens of a convenient size for investigation by a variety of other means, this method is a powerful adjunct to experimental techniques in the physics and chemistry of the solid state. The same work furnishes experimental material from which Lang and his collaborators have been able to verify, extend, and place on a more directly observational basis the dynamical theory of X-ray diffraction. Important innovations in this earlier work were the adaptation and development of the X-ray proportional counter with pulse-height discrimination for use with X-ray diffraction. And his methods of X-ray diffracted beam monochromatization. Among his recent achievements are the observation by X-ray diffraction of internal magnetic domains, the determination of the relative phases of distinct X-ray reflexions from one crystal, and the production of X-ray Moire fringes between separate crystal slices."

He won the 1997 Hughes Medal of the Royal Society "for his fundamental work on X-ray diffraction physics and for his developments of the techniques of X-ray topography, in particular in studying defects in crystal structures".