0000000000628033
AUTHOR
C. T. Zhang
Spectroscopic study of228-234Th nuclei using multi-nucleon transfer reactions
Light-actinide nuclei in the octupole deformed region have been populated using multi-nucleon transfer from Th. The energy level schemes of several thorium isotopes with A = 228-234 have been extended up to and negative parity states have been observed for the first time in Th. A systematic study of the difference in alignment between the positive- and negative-parity bands in thorium nuclei in this mass region shows that Th behave like octupole vibrators, in contrast with Th, which are octupole-deformed in character. An intrinsic electric dipole moment has been measured for the first time in Th. The small value obtained is consistent with the vibrational description of this nucleus.
Five-valence-protonN=82isotone137Cs
Yrast excitations in the N=82 isotone {sup 137}Cs have been identified for the first time in thick-target {gamma}-ray coincidence measurements for the system {sup 232}Th+{sup 136}Xe using the Gammasphere array. The {sup 137}Cs nuclei were produced in deep inelastic one-proton-transfer reactions. By-products of the main investigation were two well-developed rotational bands which were identified in heavy reaction partner products complementary to {sup 137}Cs and are tentatively assigned to the little studied nucleus {sup 231}Ac. There was no difficulty in placing the 11 observed {sup 137}Cs transitions in a yrast level scheme extending to an I{sup {pi}}=(31/2{sup {minus}}) level at 5494 keV.…
Spectroscopy of Rn, Ra and Th isotopes using multi-nucleon transfer reactions
Abstract High-spin spectroscopy of Rn, Ra and Th isotopes has been performed. The nuclei have been populated using multi-nucleon transfer reactions involving a 232 Th target and a 136 Xe 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 ( ∼28 h ) in 218,220,222 Rn, 222,224,226,228 Ra and 228,230,234 Th. 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 freq…
Observation of octupole structures in radon and radium isotopes and their contrasting behavior at high spin
Multinucleon transfer reactions have been used, for the first time, to populate high-spin bands of alternating parity states in {sup 218,220,222}Rn and {sup 222,224,226}Ra. The behavior of the angular momentum alignment with rotational frequency for the Rn isotopes is very different when compared with Ra and Th isotopes with N{approx}134, indicating a transition from octupole vibrational to stable octupole deformation. Throughout the measured spin range the values of {vert_bar}D{sub 0}/Q{sub 0}{vert_bar} remain constant for {sup 222}Ra and {sup 226}Ra and have a very small value for {sup 224}Ra, suggesting that the charge and mass distributions are not affected appreciably by rotations. {co…