Abstract: A scanning monochromator is disclosed which is capable of operation over a wide bandwidth in an ultra-high vacuum. The monochromator includes a pair of carousel assemblies carrying the optical elements which may be independently positioned translationally along the optical axis of the instrument and also rotationally, which each positioning control operable from outside of the instrument. A carousel on each of the carousel assemblies carries several optical elements and is rotatable to change which optical element is used, also from outside of the instrument.

Abstract: A method of identifying the presence, and amount, of elemental constituents in a material. The method uses an apparatus known for use in measuring extended x-ray absorption fine structure, and adapts it to the measurement of x-ray appearance potential in a manner to yield both qualitative and quantitative information about the elemental constituents of the material. The source of x-rays can be a synchrotron, which, because of its high power output, increases the speed and sensitivity of the measurements, permitting the use of less sensitive x-ray detectors to yield statistically significant data.