Orateur
Description
The GANIL accelerator complex in Caen (France) recently commissioned a new superconducting linear accelerator as part of the SPIRAL2 facility. This facility enables the production of heavy and super-heavy radionuclides via fusion-evaporation reactions at the entrance of the Super Separator Spectrometer (S$^{3}$) experimental area. There, the secondary beam undergoes mass separation and focusing to be finally delivered to the focal plane for experiments [1]. Located at the S$^{3}$ focal point, the S$^{3}$ Low Energy Branch (S$^{3}$-LEB) is a low-energy experiment dedicated to the study of nuclides using the In-Gas Laser Ionization Spectroscopy (IGLIS) technique, as well as decay spectroscopy and mass spectrometry [2]. These techniques allow to probe the structure of exotic nuclei, providing access to properties such as the mean-square charge radius, the spin and the magnetic and quadrupole moments.
Due to its limited extraction time, the current S$^{3}$-LEB gas cell allows only the study of nuclides with a half-life of approximately 600 ms. In order to enhance the experimental possibilities of S$^{3}$-LEB, an R&D platform called FRIENDS$^{3}$ (Fast Radioactive Ion Extraction and Neutralization Device for S$^{3}$) has been conceived, constructed and is currently in test phase at GANIL [3],[4],[5]. This platform is used to characterize a new gas cell design, and to study new neutralization techniques. Specifically, we aim to minimize the extraction time, while maximizing the extraction and neutralization efficiency at the same time.
The lasers required to perform In-Gas Jet Laser Ionization Spectroscopy at the FRIENDS$^{3}$ setup are delivered from the GISELE laboratory [6]. High resolution spectroscopy is achieved using a pulsed single-mode Injection-Locked Ti:sa cavity (ILC) seeded by an External Cavity Diode Laser (ECDL). However, in response to our needs for a seed with a wider tunable wavelength range, a home-made continuous wave (CW) Ti:sa laser [7] is under development.
During the first part of this contribution I will introduce the GISELE and FRIENDS$^{3}$ setups and their current status. Thereafter, recent progress regarding the CW Ti:sa and preliminary results of the laser spectroscopy of stable dysprosium obtained with the CW Ti:sa as seed, will be presented. The first result of the characterization studies of the FRIENDS$^{3}$ new gas cell will be finally reported.
Acknowledgements
S$^{3}$ has been funded by the French Research Ministry, National Research Agency (ANR), through the EQUIPEX(EQUIPment of EXcellence) reference ANR-10EQPX- 46, the FEDER (Fonds Européen de Développement Economique et Régional), the CPER (Contrat Plan Etat Région) E2S2 and E2S3, and supported by the U.S.Department of Energy, Office of Nuclear Physics, under contract No. DE-AC02-06CH11357 and by the E.C.FP7-INFRASTRUCTURES 2007, SPIRAL2 Preparatory Phase, Grant agreement No.: 212692.
S$^{3}$LEB has received funding from the French Research Ministry through the National Research Agency under contract number ANR-13-BS05-0013 and ANR-21-CE31-0001, from the Research Foundation - Flanders (FWO) under the International Research Infrastructure program number I002219N, from the Research CoordinationOffice – 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.
References
[1] A. Drouart et al. en. In: J. Phys.: Conf. Ser. 1643.1 (Dec. 2020), p. 012032.
[2] A. Ajayakumar et al. In: Nucl.Instrum.Meth.B. Vol. 539. Daejeon, South Korea, Oct. 2022, pp. 102–107.
[3] W. Dong. en. PhD thesis. Université Paris-Saclay, Nov. 2024.
[4]E. Morin et al. In: Nucl.Instrum.Meth.B 573 (Apr. 2026), p. 166027.
[5] W. Dong et al. In: (Jan. 2026). arXiv:2601.12009 [physics].
[6] A. M. Sj ̈odin et al. en. In: Hyperfine Interact 216.1-3 (Apr. 2013), pp. 121–126.
[7] V. Sonnenschein et al. In: Hyperfine Interact 241.1 (Feb. 2020), p. 32.