Enhanced electric dipole strength below particle-threshold as a consequence of nuclear deformation

Journal Article · Mon Jun 15 00:00:00 EDT 2009 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.79.061302· OSTI ID:21293741

Rusev, G; Schwengner, R; Beyer, R; Erhard, M; Junghans, A R; Kosev, K; Nair, C; Schilling, K D; Wagner, A; Doenau, F ^[1]; Grosse, E ^[1]; Frauendorf, S ^[1]

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1. Institut fuer Strahlenphysik, Forschungszentrum Dresden-Rossendorf, D-01314 Dresden (Germany)

Photoabsorption cross sections {sigma}{sub {gamma}} up to the neutron-separation energy S{sub n} were measured for the stable even-mass isotopes {sup 92-100}Mo in photon-scattering experiments. The photon-scattering data were analyzed in a novel way by taking into account the intensity of unresolved levels at high excitation energy and high level density. Simulations of {gamma}-ray cascades were performed to estimate the intensity distribution of inelastic transitions to low-lying levels and, hence, to deduce intensities and branching ratios of the ground-state transitions needed for the determination of {sigma}{sub {gamma}}. The present ({gamma},{gamma}{sup '}) data can be combined for the first time with ({gamma},n) data, which allows us to obtain {sigma}{sub {gamma}} in the energy range from about 4 MeV up to the giant dipole resonance for a series of isotopes. The {sigma}{sub {gamma}} values below S{sub n} increase with the number of neutrons above the neutron shell closure at N=50. Calculations using a quasiparticle random-phase approximation in a deformed Woods-Saxon potential describe this effect as a consequence of the increasing nuclear deformation.

• OSTI ID: 21293741
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 79, Issue 6; Other Information: DOI: 10.1103/PhysRevC.79.061302; (c) 2009 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ABSORPTION
BRANCHING RATIO
CROSS SECTIONS
DISTRIBUTION
ELECTRIC DIPOLES
ENERGY-LEVEL DENSITY
EXCITATION
GAMMA RADIATION
GROUND STATES
MASS
MEV RANGE 01-10
MOLYBDENUM ISOTOPES
NEUTRON SEPARATION ENERGY
NEUTRONS
NUCLEAR DEFORMATION
PHOTONS
RANDOM PHASE APPROXIMATION
SCATTERING
SIMULATION
WOODS-SAXON POTENTIAL