Collective states in ²³⁰Ra fed by β⁻ decay of ²³⁰Fr

Abstract

The γ-rays following the β⁻ decay of ²³⁰Fr have been investigated by means of γ-ray singles including multispectrum analysis and γγ coincidence measurements using Ge(Li) detectors. The half-life of ²³⁰Fr was measured to be 19.1 ± 0.5 s. Most of the observed transitions could be placed in a level scheme comprising 23 new excited states of ²³⁰Ra, ten of them grouped into the K^π = 0⁺ ground-state band, the K^π = 0⁻ band with its 1⁻ state at 710.9 keV and a K^π = 2⁺ γ-vibrational band with its head at 734.8 keV. It is concluded that ²³⁰Ra is a better rotator than the lighter radium isotopes, and has no ground-state octupole deformation.