Level structure of 141Ba and 139Xe and the level systematics of N=85 even-odd isotones

Journal Article · Thu Jan 31 04:00:00 EST 2002 · Physical Review C

DOI:https://doi.org/10.1103/PhysRevC.66.014305· OSTI ID:803764

Luo, Y X ^[1]; Rasmussen, J O; Hamilton, J H; Ramayya, A V; Hwang, J K; Beyer, C J; Zhu, S J; Kormicki, J; Zhang, X Q; Jones, E F; Gore, P M; Ginter, T N; Gregorich, K E; Lee, I-Yang; Macchiavelli, A O; Zielinski, P; Folden, III, C M; Fallon, P; Ter-Akopian, G M; Oganessian, Yu Ts ; Daniel, A V; Stoyer, M A; Cole, J D; Donangelo, R; Wu, S C; Asztalos, S J

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1. LBNL Library

New level schemes of {sup 141}Ba and {sup 139}Xe are proposed from the analyses of spontaneous-fission gamma data from our {sup 252}Cf spontaneous fission Gammasphere runs of 1995 and 2000. By analogy with the N = 85 even-odd isotones {sup 149}Gd, {sup 147}Sm, and {sup 145}Nd, spins and parities were assigned to the observed excited states in {sup 141}Ba and {sup 139}Xe. It appears that spherical shell model neutron excitations plus octupolephonons are an appropriate basis at the lower end of the bands. Going to higher spins it is clear that the soft rotor involving valence protons as well as neutrons becomes increasingly important in the configurations. Level systematics in the N = 85 even-odd isotones from Gd(Z=64) through Te(Z=52), are discussed. The excitation systematics and smooth trends of the analogous levels support the spin and parity assignment for excited levels observed in {sup 141}Ba and {sup 139}Xe. The level systematics and the comparison with neighboring even-even isotopes indicate that quadrupole and octupole collectivity play roles in {sup 141}Ba and {sup 139}$Xe. From Gd(Z=64) through Te(Z=52), increasing excitation energies of the 13/2{sup +} states and lowering relative intensities of the positive parity bands in the N = 85 even-odd isotones may indicate that the octupole strength is becoming weaker for the isotones when approaching the Z = 50 closed shell.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: USDOE Director, Office of Science. Office of High Energy and Nuclear Physics. Division of Nuclear Physics; National Natural Science Foundation, China (US)
• DOE Contract Number: AC03-76SF00098
• OSTI ID: 803764
• Report Number(s): LBNL--49530; B& R KB0201022
• Journal Information: Physical Review C, Journal Name: Physical Review C Journal Issue: 1 Vol. 66
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ENERGY LEVELS
EXCITATION
EXCITED STATES
GAMMASPHERE FISSION SPECTROSCOPY NUCLEAR LEVELS 141BA. 139XE
ISOTONIC NUCLEI
NEUTRONS
OCTUPOLES
PARITY
PROTONS
QUADRUPOLES
ROTORS
SHELL MODELS
SPIN
SPONTANEOUS FISSION
VALENCE