Single Axis, Two Crystal X-Ray Instrument

Abstract
Design features of a two crystal instrument capable of measurements of diffraction angles to an accuracy of the order of 0.1″ are presented. The instrument is of simple geometry, employs a stable and massive chassis, and derives its precision from components of general availability. Diffraction angles are generated in 1° increments by a precise indexing mechanism and interpolated by means of a sine arm driven by a micrometer.
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