Roux D.G.Lawrie E.A.Kheswa B.V.Khumalo N.ANoncolela S.P.Ndayishimye J.Sharpey-Schafer J.F.2025-10-292025-10-292024Roux, D.G., Bark, R.A., Lawrie, E.A., Lawrie, J.J., Ntshangase, S.S., Dinoko, T.S., Easton, J.L., Jones, P., Kheswa, B.V., Khumalo, N.A. and Majola, S.N.T., 2024. First observation of rotational bands in the nucleus 231 U. The European Physical Journal A, 60(5), p.118.https://doi.org/10.1140/epja/s10050-024-01337-zhttps://hdl.handle.net/10566/21218This work reports the first rotational bands observed in the neutron-deficient nucleus 231U. Excited states were populated in the 232Th(α,5n) reaction at a beam energy of 52 mev. Coincident decay γ-rays were measured with the high-purity germanium detectors of the afrodite spectrometer array, in conjunction with a recoil detector to discriminate against the fission background. The bands are interpreted as the ground-state band ν[633]5/2+, yrast band ν[752]5/2-, and an excited band ν[631]3/2+. Configuration assignments are supported by Cranked Shell Model and B(M1)/B(E2) calculations. The excitation energy of the ν[752]5/2- bandhead is suggested to be 113.0 kev. © The Author(s) 2024.enExcited statesGamma raysBeam energiesConfiguration assignmentnucleus 231UArticle