Shinji Kobayashi
Tokyo Polytechnic University, Japan
Title: Isotope shift of Ti spectrum in a facing target sputtering system
Biography
Biography: Shinji Kobayashi
Abstract
Laser spectroscopy is one of the useful methods of plasma diagnostics. In order to measure the plasma density and temperature, parameters of the line profile of the spectrum need to be determined. In this study, we measured the absorption spectrum of Ti atom in a facing target sputtering (FTS) system by using a Ti: sapphire laser. It is difficult to determine the parameters of the line profile of the Ti spectrum, because Ti has five stable isotopes and hence the spectra are complicated. The saturated absorption spectrum in 3d24s2→3d24s4p, 3d34s→3d24s4p, and 3d34s→3d34p electronic transitions of neutral titanium in the FTS system were measured in the range from 695 to 1005 nm. The even mass isotope shifts of 46Ti and 50Ti for 48Ti have been measured. The accuracy of absolute frequency of the Ti spectra was 0.001 cm-1. The King plot analysis was performed for those transitions. The specific mass shift of Ti I is much larger than the field shift. The several energy levels belonging to 3d34p interact with those of 3d24s4p. The specific mass shift of 3d34p depends on the contribution from 3d24s4p. The relationship between the interaction and the specific mass shift is linear. The specific mass shift of the levels belonging to 3d24s4p and 3d34p can be semi-empirically determined.