Shell model level structure of {sup 216}Fr

Journal Article · Sat Mar 01 04:00:00 EST 1997 · Physical Review, C

DOI:https://doi.org/10.1103/PhysRevC.55.1162· OSTI ID:512766

Sheline, R K ^[1]; Liang, C F; Paris, P ^[2]; Gizon, A ^[3]

---

1. Departments of Chemistry and Physics, Florida State University, Tallahassee, Florida 32306 (United States)
2. Centre de Spectrometrie Nucleaire et de Spectrometrie de Masse, Batiment 104, 91405 Campus Orsay (France)
3. Institut des Sciences Nucleaire, IN2P3, Universite Joseph Fourier, F-38026 Grenoble (France)

Sources of {sup 220}Ac in secular equilibrium with {sup 221}Pa were produced using the reaction {sup 209}Bi({sup 18}O,3n){sup 224}Pa. The alpha decay of {sup 220}Ac and coincident gamma and electron spectra were used to study the level structure of {sup 216}Fr. The levels in {sup 216}Fr can be interpreted in terms of the {pi}(h{sub 9/2}){sub 9/2}{sup 5}{nu}(g{sub 9/2}){sub 9/2}{sup 3}, {pi}(h{sub 9/2}){sub 0}{sup 4}(f{sub 7/2}){sub 7/2}{nu}(g{sub 9/2}){sub 9/2}{sup 3}, and {pi}(h{sub 9/2}){sub 9/2}{sup 5}{nu}(g{sub 9/2}){sub 0}{sup 2}(i{sub 11/2}){sub 11/2} shell model configurations. The alpha decay hindrance factors of the ground state to ground state transitions in the sequence {sup 224}Pa{r_arrow}{sup 220}Ac{r_arrow}{sup 216}Fr{r_arrow}{sup 212}At suggest the collapse of quadrupole-octupole Nilsson orbitals into the more degenerate shell model orbitals. The sequence of hindrance factors in this odd chain are mirrored in the corresponding odd proton and odd neutron sequences beginning with {sup 223}Pa and {sup 223}Th, respectively. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 512766
• Journal Information: Physical Review, C, Journal Name: Physical Review, C Journal Issue: 3 Vol. 55; ISSN PRVCAN; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ACTINIUM 220
ALPHA DECAY
ASTATINE 212
BISMUTH 209 TARGET
ELECTRON SPECTRA
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
FRANCIUM 216
GAMMA SPECTRA
GROUND STATES
NILSSON-MOTTELSON MODEL
OCTUPOLES
OXYGEN 18 REACTIONS
PROTACTINIUM 224
QUADRUPOLES
SHELL MODELS