A Preliminary List of Levels and g-Values for the First Spectrum of Thorium (Th I).

Abstract

The present state of the analysis of the first spectrum of thorium (Th I) is discussed briefly. Even and odd levels are listed in tables 1 and 2. The low even levels form terms arising from the configurations 6d2 7s2 and 6d37s. The Th I standard wavelengths that fit into the known level arrays are presented in table 3.