Investigation of fine structure energy levels of singly ionized lanthanum atom

In this study; to determine accurately the center-of-gravity wave numbers of hyperfine structure lines observed in high-resolution Fourier-Transform spectra calibrated in the spectral range of 330 nm–1450 nm (30000 cm-1–6900 cm-1) of singly ionized lanthanum (La II), to correct with high accuracy and to revise of the experimentally known lower-upper fine structure energy levels of these lines taking into account the statistical uncertainty values are aimed. The magnetic dipole A and electric quadrupole B hyperfine-structure constants, determined experimentally in the literature, of lower-upper levels of the transitions have been used in order to obtain the center-of-gravity of La II spectral lines. The unknown A&B values have been evaluated by simulate of the theoretical spectrum with experimental one. 115 La II fine structure levels experimentally known have been revised using the center-of-gravity wave numbers of analysed 344 spectral lines and of 81 spectral lines in wavelength-tables in the literature for the first time in this study. 94 of them have been calculated with the accuracy of better than 0.01 cm-1. For 34 La II levels, hyperfine-structure constants have been firstly estimated in this study.