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 can provide an intense x-ray beam, which is highly collimatedwith a minimum of divergence. It can also produce small focused x-ray spots of high intensity Capillary optics 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. At the entrance of the device, the capillaries are oriented to collect x-rays from a large area of the incident x-ray beam, while at the output the capillaries are oriented so as to produce a high intensity x-ray beam. For focusing synchrotron radiation photons, capillaries are all parallel at the entrance and directed toward a common focal spot at the output. Among the different types of polycapillaries developed up today, the monolithic concept is the most compact and robust, having an accepted use in the most advanced devices. A monolithic device consists of an entire alignment of capillaries instead of assembling an array of capillaries. To do this, a package of hundred of glass polycapillary fibers contained in a glass envelope is shaped using a heating furnace. In this way, each capillary is tapered and point towards a common focus at the output. In the present work, an x-ray beam of synchrotron radiation was focussed by means of a monolithic polycapillary. After its characterization, it was used to carry out spatially resolved x-ray fluorescence microanalysis and to establish the detection limits of the analytical technique. The goal of this work was to prove that polycapillary optic with acceptable performance can be developed by means of a simple manufacture process implemented with minimum investment.

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