Simplex splitting in the light actinides

Journal Article · Tue Apr 01 04:00:00 EST 1986 · Phys. Rev. C; (United States)

DOI:https://doi.org/10.1103/PhysRevC.33.1344· OSTI ID:6139615

Drigert, M W; Cizewski, J A

The structure of the nucleus /sup 219/Ac(Z = 89,N = 130) has been studied via the /sup 209/Bi(/sup 13/C,3n)/sup 219/Ac reaction. In-beam ..gamma..-ray spectroscopic techniques, including ..gamma..-ray and ..cap alpha..-particle excitation functions, ..cap alpha..-..gamma.. coincidence, ..gamma..-..gamma.. coincidence, and ..gamma..-ray angular distribution measurements were used in the construction of a level scheme up to a spin of J = (31/2)h at an excitation energy of 2245 keV. A total of five bands have been constructed and a series of parity doublets has been observed. For four of the bands the states have been labeled in terms of the simplex quantum number, which should be an appropriate quantum number even for octupole deformed nuclei. However, considerable simplex splitting is observed. The level scheme of /sup 219/Ac indicates that the nucleus lies in the boundary region between the single-particle shell structure seen in the nuclei immediately surrounding /sup 208/Pb and the collective rotational structure prevalent in the heavier actinides. However, no detailed model predictions are, as yet, available to describe the observed structure, which may require quadrupole, octupole, and nonaxial degrees of freedom.

• Research Organization: A. W. Wright Nuclear Structure Laboratory, Yale University, New Haven, Connecticut 06511
• OSTI ID: 6139615
• Journal Information: Phys. Rev. C; (United States), Journal Name: Phys. Rev. C; (United States) Vol. 33:4; ISSN PRVCA
• Country of Publication: United States
• Language: English

Related Subjects

651923* -- Nuclear Properties & Reactions
A=190-219
Experimental-- Energy Levels & Transitions-- (-1987)
651925 -- Nuclear Properties & Reactions
A=190-219
Experimental-- Nuclear Reactions & Scattering-- (-1987)
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE ISOTOPES
ACTINIDE NUCLEI
ACTINIUM 219
ACTINIUM ISOTOPES
ALPHA DECAY RADIOISOTOPES
ALPHA PARTICLES
ANGULAR DISTRIBUTION
ANGULAR MOMENTUM
BARYONS
BISMUTH 209 TARGET
CARBON 13 REACTIONS
CHARGED PARTICLES
CHARGED-PARTICLE REACTIONS
COINCIDENCE SPECTROMETRY
COMPOUND-NUCLEUS REACTIONS
CROSS SECTIONS
DEFORMED NUCLEI
DISTRIBUTION
ELEMENTARY PARTICLES
ENERGY LEVELS
EVEN-EVEN NUCLEI
EXCITATION FUNCTIONS
EXCITED STATES
FERMIONS
FUNCTIONS
GAMMA SPECTROSCOPY
HADRONS
HEAVY ION REACTIONS
HEAVY NUCLEI
ISOTOPES
LEAD 208
LEAD ISOTOPES
MATHEMATICAL MODELS
MICROSEC LIVING RADIOISOTOPES
NEUTRONS
NUCLEAR MODELS
NUCLEAR REACTIONS
NUCLEAR STRUCTURE
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
PARITY
PARTICLE PROPERTIES
QUANTUM NUMBERS
RADIOISOTOPES
ROTATIONAL STATES
SHELL MODELS
SPECTROSCOPY
SPIN
STABLE ISOTOPES
TARGETS