By using Mont Carlo method the simulation of emitting X-ray spectroscopy corresponding to different electron-injection direction in micro X-ray tube was performed and the optimal emitting angle was obtained. In the simulation there were electron beam with 50 keV from a point source,a silver target with 2 μm of thickness and an X-ray tube with 250 μm of beryllium window. The results indicated that in comparison with the structure of conventional transmission-type X-ray micro X-ray tube, after adjusting electron direction a decrease in interference of low energy X-ray background to characteristic X-ray of measured elements was observed in original spectroscopy. In addition the relative strength of both successive bremsstrahlung and characteristic X-ray increased in the bombardment, which was beneficial to accuracy and precision in the EDXRF analysis.%利用MC法,模拟不同电子入射方向的微型X射线管出射X射线谱,从而得出最佳入射角.模拟了50 keV能量的点源电子束、2 μm银靶、250 μm铍窗的X射线管,得到电子的最佳入射角为15°.结果表明:与传统微型透射式X射线管结构相比,调节电子入射角后的原能谱中低能X射线本底对待测元素的特征X射线的干扰减少了,并且电子束轰击靶材产生连续的韧致辐射和特征X射线的相对强度也提高了,有利于EDXRF分析的精度与准确性.
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