Palladium: a Study of Nuclear Deformation of a Refractory Element. Laser Spectroscopy at the IGISOL (Jyväskylä, Finland) and S3-LEB (GANIL, France)

Abstract

At this work, laser spectroscopy measurements on the Pd isotopic chain using different techniques are presented. Thanks to the chemically insensitive IGISOL ion-guide production method, it has been possible to reduce the existing gap in optical spectroscopy data below Z=50, created by the refractory character of these elements. A study of the deformation of palladium nuclei on the mass region 98 ≤ A ≤ 118 is performed comparing the results of two collinear laser spectroscopy measurements with state-of-art Fayans and Gogny calculations. Having 6 protons and 4 holes on his valence shell, palladium is located at the mid-shell πg_9/2, between the strongly deformed systems around zirconium (Z=40, N=60) and the spherical systems close to tin (Z=50), and are thus expected to exhibit a rather transitional character. The interpretation of the results have been done using axial and triaxial perspectives. The mean square charge radii have been extracted for the ground state of the even-even palladium isotopes on the mass region 98 ≤ A ≤ 118 and together with the magnetic dipole moments, electric quadrupole moments, nuclear spins and mean square charge radii of the odd-A ^{99,101,113,115}Pd and the isomeric state of ¹¹⁵Pd. Complementing this work, this thesis includes the work with Fabry-Pérot interferometers to support laser spectroscopy measurements. To prepare future experiments towards the proton drip line, laser resonant ionization spectroscopy measurements of stable palladium isotopes have been performed suing two different approaches. On one side, the production study of stable palladium production test using a hot-cavity catcher is presented. On the other side, the offline test and development of resonant ionization palladium schemes has been performed at the GISELE offline laser laboratory.