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Resonance laser ionization spectroscopy of stable chromium isotopes

L. Lalanne1,2,3,*, R. Mancheva1,2, M. Athanasakis-Kaklamanakis1,2, M. Heines1, Á. Koszorús1, Y. C. Liu4, J. Reilly5, C. Bernerd2, B. van den Borne1 et al.

K. Chrysalidis2, T. E. Cocolios1, K. T. Flanagan5, R. F. Garcia Ruiz6, R. P. de Groote1, R. Heinke1,2,5, J. Johnson1, P. Lassegues1, K. Mack5, B. A. Marsh2, A. McGlone5, K. M. Lynch5, G. Neyens1, R. Van Duyse1, J. Wessolek5,2, and X. F. Yang4

  • *Contact author: louis.lalanne@ijclab.in2p3.fr
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Phys. Rev. A 114, 032811 – Published 8 September, 2026

DOI: https://doi.org/10.1103/4kpl-b7cs

Abstract

Resonance laser ionization spectroscopy was conducted on stable chromium isotopes Cr50,52,53,54 using the RILIS laser ion source and the CRIS experimental apparatus at the ISOLDE/CERN facility. A unique titanium:sapphire laser-based three-step laser ionization scheme was developed to selectively and efficiently ionize and extract the Cr isotopes. Over 350 electronic transitions were observed, including several efficient transitions to autoionizing states. High-resolution spectroscopic measurements were performed with the 3d5(6S)4s a7S3→3d5(6S)4p z7P3 atomic ground-state transition to characterize the scheme and benchmark the performance of the CRIS setup. The isotope shifts δν50,52=−121(7)MHz, δν50,53=−137(6)MHz, and δν54,52=−14(6)MHz were measured, and the hyperfine structure parameter AS3=−82.64(16)MHz of Cr53 was extracted. A King plot analysis allowed reevaluation of the field shift F=−271(11)MHzfm−2 and mass shift M=105.3(30)GHzu factors of the transition with improved precision and accuracy. High-resolution measurements agree with the existing literature, supporting the accuracy and the reliability of the method for future studies involving radioactive isotopes.

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Phys. Rev. A 114, 032811– Published 8 September, 2026
  • Received 2 March 2026
  • Accepted 20 July 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Open access publication funded by CERN.

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