Dipole strength in {sup 139}La below the neutron-separation energy
- Department of Physics, Konan University, Okamoto 8-9-1, Higashinada, Kobe 658-8501 (Japan)
- Institut fuer Strahlenphysik, Forschungszentrum Dresden-Rossendorf, D-01314 Dresden (Germany)
- Department of Physics, Duke University, and Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 (United States)
The {gamma}-ray strength function is an important input quantity for the determination of the photoreaction rate and the neutron capture rate for astrophysics as well as for nuclear technologies. To test model predictions, the photoabsorption cross section of {sup 139}La up to the neutron-separation energy was measured using bremsstrahlung produced at the electron accelerator ELBE of Forschungszentrum Dresden-Rossendorf with an electron beam of 11.5 MeV kinetic energy. The experimental data were analyzed by applying Monte Carlo simulations of {gamma}-ray cascades to obtain the intensities of the ground-state transitions and their branching ratios. We found a significant enhancement of electric dipole strength in the energy range from 6 to 10 MeV that may be related with a pygmy dipole resonance. The present data are combined with photoneutron cross sections for {sup 139}La and compared with results of calculations on the basis of a quasiparticle-random-phase approximation using an instantaneous-shape sampling.
- OSTI ID:
- 21419427
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 82, Issue 2; Other Information: DOI: 10.1103/PhysRevC.82.024314; (c) 2010 The American Physical Society; ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
Similar Records
Dipole-Strength Distributions Below the Giant Dipole Resonance in the Stable Even-Mass Molybdenum Isotopes
Low-energy tail of the giant dipole resonance in {sup 98}Mo and {sup 100}Mo deduced from photon-scattering experiments
Related Subjects
ACCELERATORS
BRANCHING RATIO
BREMSSTRAHLUNG
COMPUTERIZED SIMULATION
CROSS SECTIONS
ELECTRIC DIPOLES
ELECTRON BEAMS
ELECTRONS
FORECASTING
GAMMA RADIATION
GROUND STATES
KINETIC ENERGY
LANTHANUM 139
MEV RANGE 01-10
MONTE CARLO METHOD
NEUTRON REACTIONS
NEUTRON SEPARATION ENERGY
RANDOM PHASE APPROXIMATION
RESONANCE
STRENGTH FUNCTIONS
APPROXIMATIONS
BARYON REACTIONS
BEAMS
BINDING ENERGY
CALCULATION METHODS
DIMENSIONLESS NUMBERS
DIPOLES
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENERGY
ENERGY LEVELS
ENERGY RANGE
FERMIONS
FUNCTIONS
HADRON REACTIONS
INTERMEDIATE MASS NUCLEI
IONIZING RADIATIONS
ISOTOPES
LANTHANUM ISOTOPES
LEPTON BEAMS
LEPTONS
MEV RANGE
MULTIPOLES
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
ODD-EVEN NUCLEI
PARTICLE BEAMS
RADIATIONS
RARE EARTH NUCLEI
SIMULATION
STABLE ISOTOPES