An apparatus for characterizing a library is provided in which the library contains an array of elements and each element contains a different combination of materials. The apparatus includes an x-ray beam directed at the library, a chamber which houses the library and a beamline for directing the x-ray beam onto the library in the chamber. The chamber may include a translation stage that holds the library and that is programmable to change the position of the library relative to the x-ray beam and a controller that controls the movement of the translation stage to expose an element to the x-ray beam in order to rapidly characterize the element in the library. During the characterization, the x-ray beam scatters off of the element and a detector detects the scattered x-ray beam in order to generate characterization data for the element.