Orateur
Description
The SPIRAL2-LINAC at GANIL coupled with the Super Separator Spectrometer ($S^3$) recoil separator will facilitate the production of neutron-deficient nuclei close to the proton dripline as well as super heavy nuclei via fusion-evaporation reactions, with an efficient separation from the intense background contamination [1]. At the focal plane of $S^3$, the Low Energy Branch ($S^3$-LEB) will enable low-energy nuclear physics experiments by thermalising and neutralising the nuclei in a gas cell before extraction in a supersonic gas jet. In the jet, resonant laser ionisation can serve as both a selective ion source and a method of spectroscopy.
Resonant laser ionisation spectroscopy in the low density and low temperature environment of the supersonic jet will boost the spectral resolution by an order of magnitude, while maintaining the typical efficiency of in-source laser spectroscopy [2]. The technique allows the precise investigation of isotope shifts and hyperfine structures at the extremes of the nuclear chart. This will give access to ground-state properties such as spins, charge radii and electromagnetic moments in a nuclear-model-independent framework. Combined with the PILGRIM MR-TOF and the SEASON and IDEAS3 decay stations, mass and decay measurements will also be performed. The $S^3$-LEB setup has been commissioned offline in a dedicated laboratory [3, 4], and is now installed at the focal plane of $S^3$, in preparation for online commissioning.
I will present the status of the setup, focussing on the preparation for online experiments at $S^3$, including tests in the offline laser laboratory GISELE. The first scientific objectives with short-lived nuclei in the coming years, and possibilities further on will be shown. In addition, I will present the results and perspectives of ongoing related projects, such as FRIENDS3 [5, 6], which aims at improving the extraction speed and neutralisation of the gas cell.
[1] F. Déchery et al., Nucl. Instrum. Meth. B 376, 125-130 (2016)
[2] R. Ferrer et al., Nat. Comm. 8, 14520 (2017)
[3] J. Romans, et al., Atoms 10(1), 21 (2022)
[4] A. Ajayakumar, et al., Nucl. Instrum. Meth. B 539, 102 (2023)
[5] E. Morin, et al., Nucl. Instrum. Meth. B 573, 166027 (2026)
[6] W. Dong, et al., Nucl. Instrum. Meth. B 579, 166239 (2026)
S3 has received funding from the French Research Ministry through the National Research Agency EQUIPEX (EQUIPment of EXcellence) under contract number ANR-10EQPX- 46, from the FEDER (Fonds Européen de Développement Economique et Régional) under contract number FEDER 0111251 – 21E03702, from the CPER (Contrat Plan Etat Région) under contract number 15P04209, from the U.S. Department of Energy, Office of Nuclear Physics under contract number DE-AC02-06CH11357 and from the E.C. FP7-INFRASTRUCTURES 2007 SPIRAL2 Preparatory Phase under grant agreement number 212692.
S3LEB has received funding from the French Research Ministry through the National Research Agency under contract number ANR-13-BS05-0013, from the Research Foundation - Flanders (FWO) under the International Research Infrastructure program number I002219N, from the Research Coordination Office – KU Leuven (C14/22/104), from the European Research Council under contract number ERC-2011-AdG-291561-HELIOS, from the FWO and F.R.S.-FNRS under the Excellence of Science (EOS) programme (40007501),from the European Union’s Horizon 2020 research and innovation program under grant agreement number 654002–ENSAR2–H2020-INFRAIA-2014-2015 and under grant agreement number 861198–LISA–H2020-MSCA-ITN-2019 and from IN2P3-DSM/CEA and GSI under the French-German collaboration agreement number PN1064.