Elemental mapping and microimaging by x-ray capillary optics

Abstract

Recently, many experiments have highlighted the advantage of using polycapillary optics for x-ray fluorescence studies. We have developed a special confocal scheme for micro x-ray fluorescence measurements that enables us to obtain not only elemental mapping of the sample but also simultaneously its own x-ray imaging. We have designed the prototype of a compact x-ray spectrometer characterized by a spatial resolution of less than 100 microm for fluorescence and less than 10 microm for imaging. A couple of polycapillary lenses in a confocal configuration together with a silicon drift detector allow elemental studies of extended samples (approximately 3 mm) to be performed, while a CCD camera makes it possible to record an image of the same samples with 6 microm spatial resolution, which is limited only by the pixel size of the camera. By inserting a compound refractive lens between the sample and the CCD camera, we hope to develop an x-ray microscope for more enlarged images of the samples under test.