LAUE DIFFRACTION PATTERN

in X rays, a regular array of spots on a photographic emulsion resulting from X rays scattered by certain groups of parallel atomic planes within a crystal. When a thin, pencil-like beam of X rays is allowed to impinge on a crystal, those of certain wavelengths will be oriented at just the proper angle to a group of atomic planes so that they will combine in phase to produce intense, regularly spaced spots on a film or plate centred around the central image from the beam, which passes through undeviated. Laue patterns, first detected by Max von Laue, a German physicist, are invaluable for crystal analysis.