On the nuclear structure of 229Ra

The nucleus 229Ra has been studied bia β− decay of 229Fr, the half-life of which was measured to be (50.2±0.4) s. A level scheme with seven excited levels has been constructed. In the Nilsson classification the ground state is assumed to be 52+[633↓], levels at 142.8 and 213.0 keV are described. as 12+[631↓] and 32+[631↑] and levels at 137.6 and 479.2 keV as 32−[761↑] and 12−[501↓]. The level structure of 229Ra is similar to the structure in the lighter Ra-isotopes, which have been described as octupole-deformed nuclei.