Photoionization spectra of Se have been studied by step-wise resonance laser ionization. The Rydberg series 4s$^2$4p$^3$($^4$S)np $^3$P$_{0,1,2}$ and 4s$^2$4p$^3$($^4$S)np $^5$P$_{1,2,3}$ were measured via different excitation schemes. Using the Rydberg series 4s$^2$4p$^3$($^4$S)np $^3$P$_2$ with n=15-33, the ionization potential of Se was determined with improved precision to 76658.15(2)$_{stat}$(4)$_{sys}$ cm$^{-1}$, which resolved the discrepancy in previous literatures. Autoionizing (AI) spectra between the IP and two neighboring converging limits of the Se ionic states 4s$^2$4p$^3$($^2$D$_{3/2}$) and 4s$^2$4p$^3$($^2$D$_{5/2}$) were obtained. In total eight AI Rydberg series have been observed, measured and assigned.

中文翻译：

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硒的共振激光电离光谱

已经通过逐步共振激光电离研究了硒的光电离光谱。里德堡级数 4s$^2$4p$^3$($^4$S)np $^3$P$_{0,1,2}$ 和 4s$^2$4p$^3$($^ 4$S)np $^5$P$_{1,2,3}$ 是通过不同的激励方案测量的。使用里德堡级数 4s$^2$4p$^3$($^4$S)np $^3$P$_2$，n=15-33，Se 的电离势测定精度提高到 76658.15( 2)$_{stat}$(4)$_{sys}$ cm$^{-1}$，解决了以往文献中的差异。IP 和 Se 离子态 4s$^2$4p$^3$($^2$D$_{3/2}$) 和 4s$^2$4p 的两个相邻收敛极限之间的自电离 (AI) 光谱获得了 $^3$($^2$D$_{5/2}$)。总共观察、测量和分配了八个 AI Rydberg 系列。