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  • Letter
  • Open Access

New isotope Am231

J. Khuyagbaatar1,*, P. Mosat1, J. Ballof1, R. A. Cantemir1, Ch. E. Düllmann1,2,3, K. Hermainski1,3, B. Kindler1, J. Krier1, N. Kurz1 et al.

S. Löchner1, B. Lommel1, B. Schausten1, P. Wieczorek1, and A. Yakushev1

  • *Contact author: J.Khuyagbaatar@gsi.de
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Phys. Rev. C 114, L011302 – Published 15 July, 2026

DOI: https://doi.org/10.1103/2clj-zh3s

Abstract

The present work aimed at the synthesis of the hitherto unknown Am231 and known Am229 isotopes via the 4n evaporation channels of the fusion reactions of Ca48+Re187 and Ca48+Re185, respectively. The new isotope Am231, with a half-life of 47−19+85s, was identified on the basis of five observed α-decay chains. It emits α particles with an energy of 7.11(2) MeV. An upper limit of 0.66 was estimated for the electron-capture decay branch of Am231. No α-decay chain from Am229 was observed, corresponding to a cross-section level of 0.03 nb for the detection of a single event. The α-decay properties of Am231 are discussed in the framework of the Geiger-Nuttall empirical relation.

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Phys. Rev. C 114, L011302– Published 15 July, 2026
  • Received 12 March 2026
  • Accepted 16 June 2026
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