Classification du Spectre d'Arc du Sélénium (Sel) entre 3 900 et 11 844 cm-1

Abstract

The spectrum emitted by an electrodeless discharge tube filled with pure ⁸⁰Se has been newly investigated by Fourier transform spectroscopy. The observations have led to a list of wavenumbers and estimated intensities for 360 lines in the range 3 900 to 11 844 cm^-1. The values of the known energy levels involved in the observed transitions have been improved by exploiting the high wavenumber accuracy, 3 × 10^-3 cm^-1. The fine structures of the 4p ³(⁴ S)nd ⁵ D and ³ D terms have been improved and 3 levels with J=0 are new. The fine structures of the 4p ³(⁴ S)nf ⁵ F and ⁵ F terms, which were not resolved in previous studies, are given from n=4 to n=6. It is shown that the principal quantum numbers n are in error by one unit in the compilation Atomic Energy Levels Vol. II (1952). Finally, the very regular 4p ³(⁴ S)nf ⁵ F ₅ series yields for the principal ionization energy of Se I the value: IP = 78 658.12 ± 0.1 cm^-1 (9.747 ± 0.001 eV).