Absorption Spectrum of Cd I Vapor at 30 Å Using the Background Radiation of the 2.5-GeV Bonn Synchrotron

Abstract

New resonances have been observed in the absorption spectrum of neutral cadmium vapor at wavelengths around 30 Å. These are believed to be at present the shortest-wavelength metal-vapor absorption features recorded optically. The 2.5-GeV electron synchrotron at Bonn University was used as a background source of continuous radiation. Hartree-Fock calculations enabled identification of the resonances as caused by excitation from the $3d$ shell, although somewhat larger differences between computed and observed wavelengths were found than were expected.