Spectroscopy of Rn, Ra and Th isotopes using multi-nucleon transfer reactions

High-spin spectroscopy of Rn, Ra and Th isotopes has been performed. The nuclei have been populated using multi-nucleon transfer reactions involving a 232Th target and a 136Xe projectile. This type of reaction offers the only mechanism for populating high-spin states in many of these nuclei. Interleaving bands with opposite parities have been observed to high spin (∼28ℏ) in 218,220,222Ra, 222,224,226,228Ra and 228,230,234Th. A systematic study of the rotational alignment properties of octupole bands in radon, radium and thorium isotopes reveals information concerning the role of the octupole phonon and the onset of stable octupole deformation with increasing rotational frequency. Measurement of the magnitude of the intrinsic electric dipole moment, D0, provides additional information concerning the strength of octupole interactions in these nuclei. © 1999 Elsevier Science B.V.