This Small Business Innovation Research (SBIR) Phase II project will develop a microfocus dual energy x-ray excitation beam delivery system to be used for micro x-ray fluorescence (micro-XRF) analysis. The development of this system will address critical needs in a variety of disciplines for substantially improved detection sensitivity (particularly of low atomic number elements), higher spatial resolution, better analysis accuracy, and increased throughput. The proposed project is expected to impact the $ 900 million XRF market by further accelerating the rapid adoption of this tool, which has been utilized for a variety of research and industrial applications, including: development of advanced materials, toxicology of trace metals, mapping mineral distribution in healthy and diseased biological tissues, determining efficient oil extraction methods for specific reservoirs in oil & gas, monitoring mine efficiency by analyzing mine wastes, and chemical analysis of buried structures and packaging components in the semiconductor industry. <br/><br/>Currently, achieving high spatial resolution mapping of elemental composition at the micrometer scale resolution with analysis sensitivity in the low parts per million (ppm) levels is only possible at synchrotron micro-XRFs, of which there are only a limited number of around the world, and which are often oversubscribed. The performance of existing laboratory micro-XRF systems is largely limited - in terms of focus size, focusing efficiency, and spectral response - by the x-ray optics which are employed. The project will permit the development of an innovative x-ray compound mirror lens which will enable a microfocus dual energy x-ray excitation beam delivery system with high analytical sensitivity to both low- and high-Z elements, large x-ray flux (up to thirty-fold better than leading systems), microns-scale spatial resolution, and large working distances (5 cm). This beam delivery system will be usable as an attachment in a scanning electron microscope and in a standalone micro-XRF system.