【摘要】 当X射线入射不同材料组成的界面时,在低Z材料的一侧将产生剂量增强,介绍了剂量增强效应的基本原理,并采用MCNP5构建三维铅铝屏蔽盒模型,计算了不同能量的X射线透过铅与铝产生的次级电子能谱以及穿过屏蔽盒后的金硅界面剂量深度分布。模拟计算表明,能量低于300 keV的X射线穿过铅铝屏蔽盒后的次级电子通量明显降低,剂量增强效应几乎可以忽略,界面硅一侧剂量均匀分布,并且实验结果与计算结果几乎吻合。更多还原

【Abstract】 The dose would be enhanced in low Z material when X-ray enters the interface which is constructed with different materials.The mechanic of dose enhancement is introduced in this article.The lead-aluminum shielding box model was constructed by Monte Carlo program mcnp5.The secondary electron energy spectrum generated by X-rays of different energies through lead and aluminum and the depth distribution of the gold-silicon interface after passing through the shielding box were calculated.The simulation results show that:The secondary electron flux of the X-rays below 300 keV after passing through the lead-aluminum shielding box is significantly reduced,the dose-enhancing effect is almost negligible,the dose on the interface Si side of the interface is uniformly distributed,and the experimental results are almost in agreement with the calculated results.更多还原