原子核对光电离截面的影响
Influences of nucleus on atomic photoionization cross section

利用Dirac-Slater相对论平均自洽场理论，研究了不同原子体系光电离截面在不同核模型下的差异. 考虑原子核大小时，核的尺寸效应使电子所感受到的有效核电荷减小，并进而影响到电子的概率分布及光电离截面等；对没有考虑原子核大小的点模型，由于不存在核的尺寸效应，出射光电子的波函数有较大相移，从而有可能出现Cooper极小. 当入射光子的能量远大于相关电子的电离能时，不同核模型下电子束缚能及平均半径等的差异将相对减小，从而使光电离截面随入射光子能量的变化趋于一致.
Based on Dirac-Slater relativistic average self-consistent field, the difference of photoionization cross sections within different nuclear models for different atomic systems have been studied systemically. The calculated results indicate that the effective nuclear charge of electron is decreased when the nuclear finite-size effects is taken into account. Cooper minimum may be occured within nuclear point model, it can be understood by considering the larger phase shift of outgoing photoelectron wave function after the atom absorbs one photon. If the energy of incident photon greatly exceeds the electronic photoionization threshold, the differences of bounding energy and the average radii from nucleus within different nuclear models are decreased oppositely, and the variation of photoionization cross sections with photon energy will turn to consistent.