低能γ光子及X射线在透射金属箱方向激发的次级X射线

The Secondary X-rays from foils excited by low energγand X-rays in the direction of transmission

采用Ｓｉ（Ｌｉ）Ｘ射线探测系统，以透射法测量了２４１Ａｍ和２３８Ｐｕ放射源的低能γ光子和Ｘ射线在透过不同厚度的Ｆｅ和Ｃｕ箔时激发的次级Ｘ射线相对强度的变化。实验结果表明：激发产生的Ｘ射线相对强度在实验样品厚度范围内随箔厚的增加而增加；在高原子序数材料中将产生更多的特征Ｘ射线；各次级Ｘ射线的强度与箔厚形成方式以及激发源的活度、能量有关。最后对实验结果的物理机制进行了初步探讨。

Relative intensities of secondary X-rays excited by 241Am and 238Pu sources in Fe and Cu foils with different thickness have been measured by a Si(Li) detector in the incidence direction. The experimental results indicate that:1) intensity of secondary X-rays is raised with the increase of the foil's thickness which is ranged from 5 to 100 μm; 2) there are more characteristic X-rays excited in the higher Z materials; and 3) intensity of secondary X-rays is related to activity,and energy of the exciting source and the way of the foil's formation. Finally, the mechanism for the experimental results are briefly discussed.