中文摘要：

采用孤立实激发与速度影像技术相结合的方法,研究了Eu原子4f^76p1/2ns（n=7,9）自电离过程的动力学特性,包括弹射电子的角分布和向各离子态衰变的分支比.首先,采用孤立实激发技术将Eu原子分步从基态4f^76s^2经中间态4f^76s6p激发至4f^76sns Rydberg态,并通过第三步跃迁4f^76s^＋→4f^76p1/2^＋。将其激发至4f^76p1/2ns自电离态.其次,运用速度影像技术对上述自电离过程进行探测,并通过一系列数学变换计算出该过程的弹射电子的能量分布和角向分布本文不仅分析和比较了各个态自电离衰变的分支比和各向异性参数随光子能量的变化规律,还深入讨论了它们与自电离光谱之间的对应关系.最后,依据自电离衰变的分支比,探讨了实现Eu离子粒子数反转的可能性,为实现自电离激光器提供了有价值的信息，

英文摘要：

To explore the dynamic properties of Eu 4f^76p1/2ns autoionization process,the autoionization branching ratios of ions and the angular distributions of ejected electrons from the Eu 4f^76p1/2ns（n = 7,9） autoionizing states are systematically investigated with the combination of the three-step isolated-core excitation（ICE） and the velocity-map imaging techniques The Eu 4f-76sns Rydberg states are populated via a two-step laser excitation,from which the Eu 4f^76p1/2ns autoionizing states are excited by the wavelength of the third laser around the Eu 6s^＋→6p1/2^＋ ionic resonance in order to obtain autoionization spectra and the velocity-map images of ejected electrons from the Eu 4f^76p1/2ns autoionizing states.Once the velocity-map images have been measured,both the energy distribution and angular distribution of ejected electrons can be acquired.Moreover,the spectra of the branching ratios and the anisotropic parameters within the autoionization resonances are also measured to observe their energy dependence and the relation with the autoionization spectra.Comparisons of the observed spectra of 4f^76p1/2ns autoionizing states with n = 7,8,and 9 manifest that the ICE technique is more suitable for the higher-n members of autoionization series.It is found that the Eu atoms in the 4f^76p1/2ns（n = 8,9） autoionizing states mainly decay into 4f^75d^＋（^9D） ionic state,leading to the population inversion between 4f^75d^＋（^9D） and 4f^76s^＋（^7S） or 4f^76s^＋（^9S） ionic states,which is significant for developing the autoionization laser.The angular distributions of the ejected electrons from the Eu 4f^76p1/2ns autoionizing states show simple patterns at the energy points corresponding to the peaks of autoionization spectra,and have complicated patterns in the energy regions off the peaks of autoionization spectra,especially in the regions corresponding to the sharp increase or decrease in the autoionization spectra.The above phenomena can be explained with the strength of configuratio