X射线及低能γ光子在金属箔透射面的光致电子发射产额

采用改进的密立根光电流测量法,在透射方向测量了＾２４１Ａｍ放射源的Ｘ射线及低能γ光子在透过不同厚度的Ａｌ、Ｆｅ、Ｃｕ、Ｔａ及Ｗ箔时光致电子发射的产额。结果表明：光致电子发射产额在样品厚度范围内随箔厚的增加而减少;在高原子序数材料中将产生更多的光致电子发射。提出了“射程层贡献”模型,以该模型为基础建立的计算方法所得结果与实验值间相对误差平均约为１０％。

Absolute emission yields of photon-induced electrons from foils On transmissive Surface

The absolute emission yields of photon-induced electrons from Al, Fe, Cu, Ta and W foils have been measured by the improved Millikan's method to detect the photoelectric current in the incident direction. The experimental results show that the yield of photoelectron is decreased with the increasing of the foil's thickness and there are more radiation-induced electrons emitting from the higher Z materials. A model known as " contribution of range layer" has been suggested. The calculated yields based on the model agree with the experimental data with a relative error of 10% on the average.