The nuclear structure of 223Fr

Abstract The γ-rays following the β − decay of 223 Rn have been investigated by means of γ-ray singles including multispectrum analysis, and γγ-coincidence measurements using Ge detectors. Multipolarities of 38 transitions in 223 Fr have been established by measuring conversion electrons with a mini-orange electron spectrometer. Most of the observed transitions could be placed in a level scheme comprising 53 excited states of 223 Fr. The level structure is interpreted in terms of K π = 3 2 ± and 1 2 ± parity doublet bands, and a second K π = 3 2 ± higher-lying parity doublet. The experimental data are compared with the theoretical predictions of the reflection-asymmetric rotor model.