CONICET | Buscador de Institutos y Recursos Humanos

Polycapillary optics has emerged in the last twenty years as a powerful tool for col-limating and focusing x-rays[1]. It can provide small, high intensity, focused x-rayspots. The possibilities of performing non-destructive elemental microanalysis withsynchrotron radiation by means of home-made polycapillary optics are described.We manufactured three monolithic polycapillary half-lenses using fiber glass tech-nology, which consists of drawing of package of glass capillaries at high temperaturein a heating furnace. The polycapillaries were constructed using borosilicate glass.The section of each channel was circular for the three lenses with a input diameterin the range of 0.04 0.12 mm. The hollow volume of the lenses was in the orderof 20%. The performance of polycapillary half-lenses with different geometries wasevaluated at the D09B-XRF fluorescence beamline of the Brazilian SynchrotronLight National Laboratory (LNLS)[2]. A gold knife edge scanned at the output ofthe lenses was used to determine the spot size at different distances. Measurementsof photon flux impinging on the entrance end of the lenses and photon flux leavingthe lenses were used to obtain the transmission efficiency. The lens with the bestperformance had a focal distance of 76μm and a transmission efficiency of 5%,which represented a gain factor of 22.Using the manufactured polycapillary half-lens with the best performance, wecarried out a micro-XRF experiment. The overall efficiency of the system wasstudied by means of the determination of the detection limits for several elementsin an organic sample. For Fe, Cu, Zn and As, detection limits in the order of ppmwere obtained.REFERENCES1. Kumakhov MA. Nucl. Instr. and Meth. 1990; B48: 283-286.2. P´erez C.A., Radtke M., Sanchez H.J., Tolentino H., Neuenshwander R.T.,Barg W., Rubio M., Bueno M.I.M.S., Raimundo I.M., Rohwedder J.J.R. X-RaySpectrom. 1999; 28: 320.