Enhancement of microbeam x-ray fluorescence analysis using monolithic polycapillary focusing optics

A monolithic polycapillary focusing optic was tested in the microbeam x-ray fluorescence system at the Oak Ridge Center for Manufacturing Technology. The optic was designed to cover a wide energy range from 4 keV to 20 keV. The focal spot size of the output beam at 17.4 keV (Mo K alpha) was measured to be 21 mu m full width of half maximum. An average beam intensity of 1.5 x 10(5) photon/s/mu m(2) was obtained at the focus for Mo K alpha line using a 12 W microfocus x-ray source, This intensity is about 2400 times over that of a direct beam at 100 mm away from the x-ray source. The small, intense x-ray beam obtained was used to analyze and map the compositions of different elements in industrial samples. (C) 1997 American Institute of Physics.