A new XRF spectrometer based on a ring-shaped multi-element silicon drift detector and on X-ray capillary optics

This paper describes an innovative X-ray fluorescence spectrometer designed to achieve high-energy resolution, position resolution, and detection rate in elemental mapping applications. The spectrometer is based on a ring-shaped monolithic array of silicon drift detectors (SDDs) with a hole cut in its center. A coaxial X-ray excitation beam is transported to the sample through this hole. In this way, the solid angle for the collection of the X-ray fluorescence is optimized. Moreover, the X-ray beam is collimated on the sample using capillary optics in order to obtain high photon density in a small excitation spot. Detector, optics, and generator are assembled in a compact vacuum tightened unit. The structure of the proposed spectrometer and the first experimental results of its characterization are presented. Index Terms--Elemental mapping, silicon drift detectors, X-ray optics, XRF, X-ray spectrometry.