Open AccessCharacterization of octupole-type structures inTh 221
Author(s) -
W. Reviol,
R. V. F. Janssens,
S. Frauendorf,
D. G. Sarantites,
M. P. Carpenter,
X. Chen,
C. J. Chiara,
D. J. Hartley,
K. Hauschild,
T. Lauritsen,
А. Лопез-Мартенс,
M. Esther Sanz Montero,
O. L. Pechenaya,
D. Seweryniak,
J. Snyder,
S. Zhu
Publication year - 2014
Publication title -
physical review. c. nuclear physics/physical review. c, nuclear physics
Language(s) - English
Resource type - Journals
eISSN - 1089-490X
pISSN - 0556-2813
DOI - 10.1103/physrevc.90.044318
Subject(s) - yrast , gammasphere , physics , parity (physics) , atomic physics , type (biology) , crystallography , excited state , chemistry , ecology , biology
International audienceA detailed level scheme for Th-221 has been established in an experiment using the O-18 + Pb-207 reaction at 96 MeV. The evaporation residues from this fissile system were selected with the HERCULES detector array and residue-gated gamma rays were measured with Gammasphere. Three band structures of interlinked, alternating-parity levels are observed, two of which are non-yrast. In addition, several high-lying excitations are found. The yrast band is seen up to spin-parity 37/2(-) and 39/2(+), beyond which a high-spin feeding transition is observed. The non-yrast sequences are interpreted as parity-doublet structures, based on a configuration similar to that of the yrast band in Th-223 (K = 5/2). The key properties of even-odd nuclei in this mass region [B(E1)/B(E2) and B(M1)/B(E2) ratios, spin alignments, parity splittings] are reviewed