Revised Landé gJ-factors of some 141Pr II levels using collinear laser ion beam spectroscopy

•Doppler-free method was used to study the weak field Zeeman effect in fast Pr ions.•We have demonstrated the usefulness of the CLIBS for studies of the Zeeman effect.•Accurate measurements of the Landé factors have been made for several levels of Pr II.

The Zeeman effect of singly ionized praseodymium spectral lines was studied at small magnetic fields up to 334 G, using the high-resolution spectroscopic method of collinear laser-ion-beam spectroscopy (CLIBS), where a collimated fast ion beam is superimposed with a counter propagating laser beam tuned to the desired transition. This nearly Doppler-effect-free technique enables to observe linewidths as low as 100 MHz and thus to record the Zeeman patterns of the hyperfine structure of the investigated spectral lines.From the Zeeman patterns of 21 lines of Pr II lines in the range 570.45-609.038 nm we have re-determined the Landé gJ-factors of 14 levels of the f3dodd and 16 levels of the f3p and f2d2even configurations.The obtained experimental Landé factors are compared with available earlier measurements as well as with theoretical calculations.