A Dispersive Method of Measuring Extended X-Ray Absorption Fine Structure

A novel method of EXAFS measurement has been developed, in which all the data points of a spectrum are collected simultaneously. A convergent X-ray beam, whose energy varies with beam direction, is realized with a transmission-type (Laue-case diffraction) crystal disperser. By measuring the spatial intensity distribution across the beam path behind the focus at which the specimen was placed, an EXAFS spectrum of an iron metal foil is measured in about 15 hr with a statistical accuracy better than 0.16% using a sealed-off X-ray tube operated at 15 keV and 35 mA. Some measures to shorten the measuring time to the order of minutes are discussed.