Focusing synchrotron radiation with home-made polycapillary x-ray optics

PEREZ, R.D; SÁNCHEZ H.J.; PÉREZ C. A.; RUBIO M.

Campinas, Brasil

Workshop; XVIII Reunião Annual de Usuários. Laboratório Nacional de Luz Síncrotron; 2008

Brazilian Synchrotron Light Laboratory

Polycapillary optics has emerged in the last twenty years as a powerful tool for collimating and focusing x-rays. It can provide small, high intensity, focused x-ray spots. The possibilities of performing non-destructive elemental microanalysis with synchrotron radiation by means of home-made polycapillary optics are described. We manufactured three monolithic polycapillary half-lenses using fiber glass technology, which consists of drawing of package of glass capillaries at high temperature in a heating furnace. The polycapillaries were constructed using borosilicate glass. The section of each channel was circular for the three lenses with a input diameter in the range of 0.04-0.12 mm. The hollow volume of the lenses was in the order of 20%. The performance of polycapillary half-lenses with di®erent geometries was evaluated at the D09B-XRF Fluorescence beamline of the Brazilian Synchrotron Light National Laboratory (LNLS). A gold knife edge scanned at the output of the lenses was used to determine the spot size at diferent distances. Measurements of photon flux impinging on the entrance end of the lenses and photon flux leaving the lenses were used to obtain the transmission efficiency. The lens with the best performance had a focal distance of 76 micros and a transmission efficiency of 5%, which represented a gain factor of 22. Using the manufactured polycapillary half-lens with the best performance, we carried out a micro-XRF experiment. The overall efficiency of the system was studied by means of the determination of the detection limits for several elements in an organic sample. For Fe, Cu, Zn and As, detection limits in the order of ppm were obtained.and a transmission efficiency of 5%, which represented a gain factor of 22. Using the manufactured polycapillary half-lens with the best performance, we carried out a micro-XRF experiment. The overall efficiency of the system was studied by means of the determination of the detection limits for several elements in an organic sample. For Fe, Cu, Zn and As, detection limits in the order of ppm were obtained.