相对论效应对Na原子激发态2p光电离过程的影响

Relativistic Effects in 2p Photoionization from the Excited States of Sodium Atoms

在多组态Dirac-Fock相对论理论框架下,研究了入射光子能量为54eV时Na原子2p^63p激发态2p的光电离过程.结果表明:相对论效应对原子光电离过程有非常明显的影响;虽然相对论效应对相应电离能的影响有限,但可使光电子的强度分布产生实质性变化,从而使两激发态2p^63p(2P1/2,3/2)的光电子谱的结构完全不同;而在非相对论极限下,两初态2p^63p(2P1/2,3/2)的光电子谱几乎完全相同.该研究可为获得有关激发态光电离过程的相对论效应信息提供一种方法.

Based on the multi-configuration Dirac-Fock method,2p photoionization process of sodium atoms from the initial state 2p^63p were investigated at a photon energy of 54 eV.Usually the relativistic effect has very obvious influence on atomic photoionization process.The influence of relativistic effects on the photoionization thresholds is negligible,but it can produce substantial change in the intensity distribution in photoelectron spectra,so that the spectra structures from the initial states 2p^63p(2P1/2,3/2)are completely different.In the nonrelativistic limit,as generally expected,the spectra structures from the two states are almost identical.Furthermore,this study demonstrates the information that may be obtained regarding the relativistic effects in the photoionization processes from excited states.