Low-energy Coulomb excitation of ⁶²Fe and ⁶²Mn following in-beam decay of ⁶²Mn

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Sub-barrier Coulomb-excitation was performed on a mixed beam of ⁶²Mn and ⁶²Fe, following in-trap β⁻ decay of ⁶²Mn at REX-ISOLDE, CERN. The trapping and charge breeding times were varied in order to alter the composition of the beam, which was measured by means of an ionisation chamber at the zero-angle position of the Miniball array. A new transition was observed at 418 keV, which has been tentatively associated to a (2⁺,3⁺)→1⁺g.ₛ. transition. This fixes the relative positions of the β-decaying 4⁺ and 1⁺ states in ⁶²Mn for the first time. Population of the 2⁺₁ state was observed in ⁶²Fe and the cross-section determined by normalisation to the ¹⁰⁹Ag target excitation, confirming the B(E2) value measured in recoil-distance lifetime experiments.