Measurements of multipolarities in 225Ra

Abstract

Multipolarities of 45 transitions in 225Ra have been established by investigating the radiations associated with the β− decay of 225Fr. The study includes β−, e− and γ-singles spectra, e−γ- and γγ-coincidence measurements. The conversion electrons were measured with a mini-orange electron spectrometer, and the γ-spectra with Ge detectors. The multipolarities obtained from the measured conversion coefficients support the assignments of spin-parity doublets thus giving evidence for a stable octupole deformation of this nucleus. The negative parity of the 394.2 keV level established in the present work indicates that this level is a candidate for the parity-doublet partner of the (5/2)+ state at 236.3 keV.