Low-energy Coulomb excitation of $^{62}$Fe and $^{62}$Mn following in-beam decay of $^{62}$Mn

TL;DR

This study investigates the low-energy Coulomb excitation of $^{62}$Fe and $^{62}$Mn isotopes following in-beam decay, revealing new nuclear transition data and confirming previous lifetime measurements.

Contribution

It provides the first measurement of the relative positions of key states in $^{62}$Mn and observes a new transition at 418 keV, enhancing understanding of these isotopes' structure.

Findings

Observation of a new 418 keV transition in $^{62}$Mn.

Confirmation of $B(E2)$ value in $^{62}$Fe from Coulomb excitation.

First determination of the relative positions of $^{62}$Mn states.

Abstract

Sub-barrier Coulomb-excitation was performed on a mixed beam of $^{62}$Mn and $^{62}$Fe, following in-trap $\beta^{-}$ decay of $^{62}$Mn 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 $(2^{+},3^{+})\rightarrow1^{+}_{g.s.}$ transition. This fixes the relative positions of the $\beta$-decaying $4^{+}$ and $1^{+}$ states in $^{62}$Mn for the first time. Population of the $2^{+}_{1}$ state was observed in $^{62}$Fe and the cross-section determined by normalisation to the $^{109}$Ag target excitation, confirming the $B(E2)$ value measured in recoil-distance lifetime experiments.