Absorber for measuring the transmission of a polycapillary focusing optical lens

摘要

In this paper, we report a simple and convenient method for measuring the transmission of the polycapillary focusing optical lens in a large energy range. In the measurement, a low-power micro-focus source, a lens an absorber stacked by the aluminum absorption foils, and a detector were placed in a line. The absorber was used to reduce the dead time of the detector. Compton scattering effect in the absorption foils and the air gaps must be considered. Thus, for the returning to the original X-ray fluorescence spectrum without absorber, the attenuation coefficient of the aluminum absorber was respectively researched by calculation and simulation. The transmission efficiency of the lens can be obtained by comparing the X-ray fluorescence spectrums whether the lens was placed. The transmission efficiency to X-rays below 8 keV cannot be measured because the X-rays below 8 keV were completely absorbed by the aluminum absorption foils.