金属二次电子发射系数表达式

Formula for secondary electron yield from metals

根据二次电子发射的主要物理过程,推导出二次电子发射系数和单位背散射电子产生的内二次电子数与原电子产生的内二次电子数之比、原电子入射能量、参数、最大二次电子发射系数、背散射系数之间的关系式。根据实验结果,给出了2～10keV比率的表达式。根据推导的关系式,用实验数据分别计算出6种金属的平均参数。发现6种金属的平均参数都近似为一个常数11.89(eV)0.5。根据推导的关系式和计算的参数,推导出以背散射系数、原电子入射能量和最大二次电子发射系数为变量的二次电子发射系数通式。用该通式计算出二次电子发射系数,并与相应的实验值进行了比较,最后成功地推导出金属2～10keV的二次电子发射系数通式。

On the basis of the dominant physical processes of secondary electron emission, the relationship among secondary electron yield, the ratio of the mean secondary electron generation of one backscattered electron to that one of a primary electron, primary energy, the parameter E（z）, maximum yield and backscattered electron coefficient was deduced. From the experimental results, the formula for the ratio in the energy range of 2 to 10 keV was given. Based on the relationship deduced, the parameters E（z） related to six metals were computed with experimental results, respectively. The parameter E（z） related to six metals is found to be approximately 11.89（eV）~＇~. Based on the deduced relationship and the computed parameter, a universal formula for expressing the secondary electron yield as a function of maximum yield, baekseattered electron coefficient and the primary energy was deduced. The secondary electron yield calculated from this universal formula and the yields measured experimentally from metals were compared. Therefore, the formula presented is universal for secondary eleetron yields from metals in the energy range of 2 to 10 keV.