Resonance Laser Ionization Spectroscopy of Selenium

TL;DR

This study used resonance laser ionization spectroscopy to precisely measure the ionization potential of selenium and to analyze its autoionizing spectra, resolving previous discrepancies and identifying multiple Rydberg series.

Contribution

The paper presents the first detailed measurement of selenium's ionization potential using Rydberg series and maps its autoionizing spectra with new assignments, improving understanding of selenium's atomic structure.

Findings

Ionization potential of Se determined as 76658.15 cm$^{-1}$ with high precision.

Eight autoionizing Rydberg series observed and assigned.

Resolves previous discrepancies in selenium ionization energy measurements.

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.