Analysis and parametric study of complex spectra with the help interpretation of hyperfine structures: spectrum I and spectrum II of praseodymium

The analysis of spectrum l and spectrum II of Praseodymium bas been continued, relying on the high resolution experimental material available between 2780 and 27920 cm^-1. In these spectra (produced by Fourier transform or with gratings), the resolution is sufficiently high, so that the study of the hyperfine structure which affects all levels becomes a precious tool for the classification and the study of the levels. This tool bas been improved and has been used in the different phases of the present work. Relying on experimental data and on previsions obtained by parametric calculations, the list of known energy levels has been incremented. Characteristics of these levels (energy, J, g, hfs splitting) have been specified or determined. A large number of data have been gathered and are presently only partially published, concerning the energy levels (539 in PrI,292 in PrII), concerning the lines (more than 13000 lines) and their classification. The present memoir gives a detailed description of what is available in the studied range. The theoretical interpretation by the Slater-Condon-Racah method reaches a high degree of complexity, in particular for the even configurations: in the case of the mixed even configurations 4f²5d6s² + 4f²5d²6s (PrI) et 4f²5d6s + 4f²5d² + 4f³6p (PrII), the study of the fine and hyperfine structures concerns an exceptionally large number of levels, whereas the comparison between theory and experiment, as well as the optimised values of the parameters provide a precise test of the validity of the method