The beam-foil excitation technique applied to heavy ion beams (20< Z

Abstract

The beam-foil excitation technique applied to heavy elements (20< Z<81) has been studied by means of a 600-kV heavy-ion accelerator, equipped with a universal ion source. The emission spectra of the foil-excited ion beams have been studied, and intensity ratios of resolved doublet and triplet components have been measured. A comparison with theoretical predictions and earlier experimental data indicates a lack of thermodynamical equilibrium at high initial ion energies. Scattering in the carbon foils has been studied by measuring angular distributions of penetrating radioactive 85Kr ion beams. The experimental reduced scattering angle shows satisfactory agreement with theoretical estimates, based on a Thomas-Fermi potential. In Zn, Sr I and Ba I, a false cascading tail has been observed for resonance transitions, giving rise to large systematic errors. It has been attempted to reveal the causes of this cascading by studying lifetimes as a function of initial energy and ion current.