{beta}-decay measurements for N>40 Mn nuclei and inference of collectivity for neutron-rich Fe isotopes

Journal Article · Sun May 15 00:00:00 EDT 2011 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.83.054312· OSTI ID:21502459

Daugas, J M; Delaroche, J -P; Belier, G; Girod, M; Meot, V; Perru, O; Roig, O; Sauvestre, J E ^[1]; Matea, I; Hammache, F; Ibrahim, F; Libert, J; Stefan, I; Verney, D ^[2]; Pfuetzner, M; Sawicka, M; Zylicz, J ^[3]; Becker, F; Grawe, H; Mayet, P ^[4]

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1. CEA, DAM, DIF, F-91297 Arpajon Cedex (France)
2. Institut de Physique Nucleaire, IN2P3-CNRS and Universite Paris-Sud, F-91406 Orsay Cedex (France)
3. Institute of Experimental Physics, Warsaw University, PL-00681 Warsaw, Hoza 69 (Poland)
4. Gesellschaft fuer Schwerionenforschung, D-64291 Darmstadt (Germany)

A decay spectroscopic study of the neutron-rich isotopes has been performed using fragmentation of a {sup 86}Kr primary beam. Fragments from this reaction have been selected by the LISE2000 spectrometer at the Grand Accelerateur National d'Ions Lourds (GANIL). Half-lives of 29 isotopes, including the first ones identified for {sup 61}Ti (15{+-}4 ms), {sup 64}V (19{+-}8 ms), and {sup 71}Fe (28{+-}5 ms), have been determined and compared with model predictions. {sup 67,68}Mn {beta}-delayed {gamma} rays were observed for the first time. The branching for the {beta}-delayed neutron emission was measured to be greater than 10(5)% in the {sup 67}Mn decay. The {sup 67}Fe isomeric level is firmly determined at higher energy than assigned in previous works. The excitation energies of the first (2{sup +}) and (4{sup +}) states of {sup 68}Fe are suggested to lie at 522(1) and 1389(1) keV, respectively, thus bringing confirmation of assignments based on in-beam {gamma}-ray spectroscopy. Beyond-mean-field calculations with the Gogny D1S force have been performed for even-mass nuclei through the Fe isotopic chain. Not only {sup 68}Fe but most of the neutron-rich Fe isotopes with neutron numbers below N=50 are interpreted as soft rotors. The calculated mean occupancy of the neutron g{sub 9/2} and d{sub 5/2} orbitals in correlated ground states is steadily growing with increasing neutron number throughout the isotopic chain. Interpretation of {sup 67}Fe data is based upon the present calculations for the {sup 66}Fe and {sup 68}Fe even cores.

• OSTI ID: 21502459
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 83, Issue 5; Other Information: DOI: 10.1103/PhysRevC.83.054312; (c) 2011 American Institute of Physics; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ALLOCATIONS
BETA DECAY
BRANCHING RATIO
DELAYED NEUTRONS
EMISSION
EXCITATION
FRAGMENTATION
GAMMA RADIATION
GAMMA SPECTROSCOPY
GANIL CYCLOTRON
GROUND STATES
HALF-LIFE
IRON 66
IRON 67
IRON 68
IRON 71
KEV RANGE
KRYPTON 86
MANGANESE 67
MANGANESE 68
MASS
MEAN-FIELD THEORY
NEUTRON-RICH ISOTOPES
TITANIUM 61
VANADIUM 64
ACCELERATORS
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CYCLIC ACCELERATORS
CYCLOTRONS
DECAY
DIMENSIONLESS NUMBERS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENERGY LEVELS
ENERGY RANGE
ENERGY-LEVEL TRANSITIONS
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
FERMIONS
FISSION NEUTRONS
HADRONS
HEAVY ION ACCELERATORS
INTERMEDIATE MASS NUCLEI
IONIZING RADIATIONS
IRON ISOTOPES
ISOCHRONOUS CYCLOTRONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KRYPTON ISOTOPES
MANGANESE ISOTOPES
MILLISECONDS LIVING RADIOISOTOPES
NANOSECONDS LIVING RADIOISOTOPES
NEUTRONS
NUCLEAR DECAY
NUCLEI
NUCLEONS
ODD-EVEN NUCLEI
ODD-ODD NUCLEI
RADIATIONS
RADIOISOTOPES
SPECTROSCOPY
STABLE ISOTOPES
TITANIUM ISOTOPES
VANADIUM ISOTOPES