First in-gas laser spectroscopy with S3-LEB

by Anjali Ajayakumar

Ajayakumar¹, Y.Balasmeh², L. Caceres¹, A. Claessens⁴, P. Delahaye¹, W.Dong³, R. Ferrer⁴, X. Fléchard², S. Franchoo³, S. Geldhof¹, N. Lecesne¹, R. Leroy¹, V.Manea³, I.Moore⁵, A. Ortiz-Cortes¹, J. Romans⁴, A. Roubin⁴, H. Savajols¹, S.Sels⁴, P. Van Duppen⁴, K.Wendt⁶

¹GANIL, CEA/DRF-CNRS/IN2P3, B.P. 55027, 14076 Caen,
²Normandie Université, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, F-14000 Caen, France
³IIJCLab, Université Paris-Sud 11, CNRS/IN2P3 91406 Orsay
⁴KU Leuven, Instituut voor Kern- en Stralingsfysica, B-3001 Leuven, Belgium
⁵University of Jyväskylä, FI-40014 University of Jyväskylä,Jyväskylä, Finland
⁶Institut für Physik, Johannes Gutenberg-Universität Mainz, 55128 Mainz, Germany

Abstract: The S³-LEB (Super Separator Spectrometer-Low Energy Branch) is a low energy radioactive ion beam installation dedicated to the study of exotic nuclei, which is currently under commissioning as a part of the GANIL-SPIRAL2 facility [1]. High intensity primary beams delivered by the superconducting LINAC of SPIRAL 2 will allow increased production rates of nuclei by fusion evaporation reactions and thus will facilitate the exploration of the neutron-deficient and heavy-mass extremes of the nuclear chart. The reaction products will be separated by the recoil separator S³ and will be delivered to the LEB installation coupled to the S³ focal plane [2].

S³-LEB is a gas cell setup where the radioactive ions of interest are thermalized, neutralized and then selectively laser ionized either inside the gas cell or in a hypersonic gas jet environment created after the gas cell using a De-Laval nozzle. It is then followed by radiofrequency quadrupole ion guides, which allows efficient transmission of the ions to a Multi-Reflection Time of Flight Mass Spectrometer (MR-TOF MS) for further beam purification and detection. First offline results from S³-LEB were published recently presenting the commissioning of laser systems and conditions for optimum operation of the ion guides obtained using an alkali ion source [3].

We present the progress in the offline commissioning of the S³-LEB setup. The first laser spectroscopy in the gas cell, as well as the transport of laser ions, bunching and trapping in the MR-TOF MS will be presented For the offline commissioning, Er laser ions which is one the day 1 campaign case, are produced by heating a filament installed in the gas cell for the offline commissioning.

References:
[1] Grand Accélérateur National d’Ions Lourds, URL: https://www.ganil-spiral2.eu/en/
[2] F. Déchery et al., Eur. Phys. J. A 51, 66 (2015), URL: https://doi.org/10.1140/epja/i2015-15066-3
[3] J.Romans et al., Atoms, 10, 21 (2022) URL : https://doi.org/10.3390/atoms10010021