Resonance Laser Ionization Spectroscopy of Selenium

Abstract

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.