Inner electron excitation of iodine in the gaseous and solid phase

Abstract

The absorption spectra of gaseous and solid iodine have been measured in the photon energy range of 45-160 eV. The radiation of the 7.5 GeV electron synchrotron DESY was used as the light source. The intensity distribution of the 4d→εf continuum is discussed. A fine structure, similar in both phases, is found near the low-energy side of this continuum. This fine structure can be ascribed to transitions of 4d5/2 and 4d3/2 electrons into the lowest empty molecular orbital and into Rydberg states of the molecule. One-electron level energies and the 4d3/2, 4d 5/2 ionization energies (58.95, 57.25 eV±0.2 eV) are deduced from the observed spectra. A rediscussion of the optical spectrum of the iodine molecule is given in the light of these results.