Spectra of Cd, In, Sb and Te in laser produced plasmas (5-9.2 A) and survey of 2p6nl energy levels in the sodium isoelectronic sequence (Zn XX-Nd L)

The emission spectra of plasma produced by frequency-double Nd:YAG laser irradiation (0.53 μm, 600 ps, 5x1014 W cm-2) of Cd, In, Sb and Te have been photographed in the region 5.0-9.2 A by means of a flat crystal spectrograph. The transitions from 2p6nl (n = 4-7) to 2p63l' in sodium-like ions are identified by comparison between experimental wavelengths λexp and predictions λREL of the relativistic parametric potential method. By extending these comparisons to the levels of lower-Z elements, systematic trends of Eexp - EREL = f(Z) are derived. The resulting semi-empirical energies are listed from Zn XX to Nd L and lead to recommended wavelengths and to ionization limits. Some features of magnesium-like ion spectra (Cd36+ through Te40+) which overlap sodium-like ion spectra, are briefly described. (orig.)