CONICET | Buscador de Institutos y Recursos Humanos

Polycapillary optics has emerged in the last twenty years as a powerful tool for collimating and focusing x-rays. It is based on transport of x-rays through glass capillaries by external total reflection (TR) at the glass surfaces. Multiple reflections in the TR regime lead x-rays over large angles in the capillaries. In this way, intensity losses in the incident x-ray beam can be kept small, even if the capillary is being bent over several degrees. Polycapillary optics consists of an array of large numbers of curved glass capillaries to collect and steer x-rays. In the present work, an x-ray beam of synchrotron radiation was focussed by means of monolithic polycapillaries with different geometries. They were made by drawing packages of glass capillaries at high temperature in a heating furnace. A characterization of these lenses describing their focal dimensions, focal distances, transmission efficiencies and gains was done for white beam. The most efficient lenses were used to implement confocal x-ray fluorescence microanalysis. The confocal XRF consists of X-ray lenses in the excitation as well as in the detection channel. In this configuration, a micro volume defined by the overlap of the foci of both x-ray lenses is analysed. Scanning this micro volume through the sample can be performed a study in 1-3 dimensions. Since this analysis is non-destructive, it has proved to be very useful for the study of paints in art, industry and biological investigations.