Scaled electron ionization cross sections in the Born approximation for atoms with 55< or =Z< or =102
Scaled electron ionization cross sections in the Born approximation for atoms with 55< or =Z< or =102
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55< 或 =Z< 或 =102 原子的玻恩近似中的缩放电子电离截面
DOI：
10.1103/physreva.20.445
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发表时间：
1979
期刊：
影响因子：
--
通讯作者：
E. J. Mcguire
中科院分区：
文献类型：
--
作者：
E. J. Mcguire
使用玻恩近似的广义振子强度公式，作者计算了 58< 或 =Z< 或 =102 的每四个原子的所有重要子壳层以及 Hg 的电子电离截面。使用的计算近似 Herman-Skillman 波函数和特征值。横截面以比例形式呈现，基本上仅取决于电离能。缩放横截面与实验能量一起用于计算 Cs、Cs/sup +/、Ba、Ba/sup +/、Au、Hg、Tl、Tl/sup +/ 和 Pb 的横截面。如此计算的横截面与测量结果非常吻合。内壳电离和激发后的自电离都是横截面的重要贡献者。使用缩放程序计算惰性气体亚稳态能级的电子电离截面，与 Ne 和 A 的测量值非常一致。使用缩放程序计算顺序电离 Ni/sup +1/--Ni/sup +14/ 和 Au/sup +3/--Au/sup +14/ 的截面，并将其与从 Lotz 半经验表达式获得的截面进行比较。 Ni 离子的一致性较好，但 Au 离子的一致性较差。 Lotz 的表达式比 4d、4f 和 5d 子壳的缩放横截面小 3 倍。有人认为，由于缺乏对这些子壳的测量，无法在 Lotz 的半经验表达式中进行正确的参数化。« less
Using the generalized oscillator-strength formulation of the Born approximation, the author calculated electron ionization cross sections for all significant subshells of every fourth atom with 58< or =Z< or =102, and for Hg. The calculations used approximate Herman-Skillman wave functions and eigenvalues. The cross sections were put in scaled form, depending essentially on ionization energy only. The scaled cross sections were used with experimental energies to calculate the cross sections for Cs, Cs/sup +/, Ba, Ba/sup +/, Au, Hg, Tl, Tl/sup +/, and Pb. The cross sections so calculated were in good agreement with the measurements. Both inner-shell ionization and excitation followed by autoionization were prominent contributors to the cross section. The scaling procedure was used to calculate the electron ionization cross section of the noble-gas metastable levels, and there is excellent agreement with measured values for Ne and A. The scaling procedure was used to calculate cross sections for the sequential ionization Ni/sup +1/--Ni/sup +14/ and Au/sup +3/--Au/sup +14/, which were compared with cross sections obtained from the semiempirical expression of Lotz. Good agreement was found for the Ni ions, but there was poor agreement for the Au ions. Lotz's expression is a factor of 3 smaller than ourmore » scaled cross section for the 4d, 4f, and 5d subshells. It is suggested that the absence of measurements on these subshells precluded correct parametrization in the semiempirical expression of Lotz.« less