Neutron one-quasiparticle states in {sup 251}Fm{sub 151} populated via the {alpha} decay of {sup 255}No

Journal Article · Sat Jan 15 04:00:00 EST 2011 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.83.014315· OSTI ID:21499337

Asai, M; Tsukada, K; Ishii, Y; Toyoshima, A; Ishii, T; Nagame, Y; Nishinaka, I ^[1]; Haba, H ^[2]; Ichikawa, T ^[3]; Kojima, Y ^[4]; Sueki, K ^[5]

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1. Advanced Science Research Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195 (Japan)
2. Nishina Center for Accelerator-Based Science, RIKEN, Wako, Saitama 351-0198 (Japan)
3. Yukawa Institute for Theoretical Physics, Kyoto University, Kyoto 606-8502 (Japan)
4. Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527 (Japan)
5. Department of Chemistry, University of Tsukuba, Tsukuba, Ibaraki 305-8571 (Japan)

Excited states in {sup 251}Fm populated via the {alpha} decay of {sup 255}No are studied in detail through {alpha}-{gamma} coincidence and {alpha} fine-structure measurements. Five excited states reported previously in {sup 251}Fm are firmly established through the {alpha}-{gamma} coincidence measurement, and rotational bands built on one-quasiparticle states are newly established through the {alpha} fine-structure measurement. Spin-parities and neutron configurations of the excited states in {sup 251}Fm as well as the ground state of {sup 255}No are definitely identified on the basis of deduced internal conversion coefficients, lifetimes of {gamma} transitions, rotational-band energies built on one-quasiparticle states, and hindrance factors of {alpha} transitions. It is found that the excitation energy of the 1/2{sup +}[620] state in N=151 isotones increases with the atomic number, especially at Z{>=}100, while that of the 1/2{sup +}[631] state decreases at Z=100. Ground-state deformations and energies of neutron one-quasiparticle states in the N=151 isotones are calculated using a macroscopic-microscopic model, and the energy systematics of the one-quasiparticle states in the isotones are discussed in terms of the evolution of nuclear deformation involving the hexadecapole ({beta}{sub 4}) and hexacontatetrapole ({beta}{sub 6}) deformations.

• OSTI ID: 21499337
• Journal Information: Physical Review. C, Nuclear Physics, Journal Name: Physical Review. C, Nuclear Physics Journal Issue: 1 Vol. 83; ISSN 0556-2813; ISSN PRVCAN
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ACTINIDE NUCLEI
ALPHA DECAY
ALPHA DECAY RADIOISOTOPES
ANGULAR MOMENTUM
ATOMIC NUMBER
BARYONS
BETA DECAY RADIOISOTOPES
CONVERSION
DECAY
DEFORMATION
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTARY PARTICLES
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EVEN-ODD NUCLEI
EVOLUTION
EXCITATION
EXCITED STATES
FERMIONS
FERMIUM 251
FERMIUM ISOTOPES
FINE STRUCTURE
GROUND STATES
HADRONS
HEAVY NUCLEI
HOURS LIVING RADIOISOTOPES
INTERNAL CONVERSION
ISOTONIC NUCLEI
ISOTOPES
LIFETIME
MINUTES LIVING RADIOISOTOPES
NEUTRONS
NOBELIUM 255
NOBELIUM ISOTOPES
NUCLEAR DECAY
NUCLEAR DEFORMATION
NUCLEI
NUCLEONS
PARTICLE PROPERTIES
RADIOISOTOPES
ROTATIONAL STATES
SPIN