Ganil Ion Source using Electron Laser Excitation – GISELE

From the beginning, the study of nuclei far from stability constitutes the history of nuclear physics and is nowadays making great strides. Among the most short-lived makes up nuclides, those situated at the frontiers of our knowledge are qualified as 'exotic'. The study of those nuclei gives us the chance to have access to new information on the nuclear structure and then to test our understanding of nuclear matter and its validity when this matter is pushed on extreme states. The production of exotic beams has been a permanent challenge to carry on their studies. These difficulties have left a huge part of the neutron rich nuclei unstudied. To reach this large domain of intact discoveries, it is necessary to produce these nuclei in sufficient quantities as ion beams. For this purpose, the study of these exotic nuclei is often hampered by their low intensities and the overwhelming presence of unwanted species in the beam. The development of the laser ion source for rare nuclei has mostly overcome this limitation and has allowed the study of previously unknown exotic nuclei. With such an installation at the new international project SPIRAL2, the major axes of the physics case studied at this facility will be the study of the magicity of neutron rich nuclei, the r-process study on nuclear astrophysics, the measurements of the fundamental properties of the very exotic nuclei such as the shape or the mass. This document proposes the construction of a solid state resonant laser system at the GANIL on line separator SIRa (Séparateur d'Ions Radioactifs). The funding for the whole laser ion source system as well as a two year post doc position is requested. This project will be driven by the two partners GANIL and IPNO where a laser ion source is under construction at ALTO. The collaboration with the Physics Institut of the Mainz University will afford their precious expertise in this domain. The aim of this R&D work is to end up with the realisation fo a key experiment at SIRa using the Magnesium 22 and laser on, to install a laser spectroscopy experiment to measure the nuclear charge radii, in particular for the Iron nuclei. For that purpose, the ionization schemes of the Mg and Fe will first be developed (with respectively 2 step - 2 color and 3 step – 3 color). The R&D performed with this laser ion source will allow in the future to adapt such a set up for the SPIRAL1 and SPIRAL2 facilities and the experimental areas (S3, DESIR…)