Gamma-ray strength functions and their relation to astrophysics

Journal Article · Fri Oct 28 04:00:00 EDT 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3628386· OSTI ID:21612057

Larsen, A C; Buerger, A; Guttormsen, M; Hagen, T W; Nyhus, H T; Rekstad, J B; Renstroem, T; Rose, S J; Ruud, I E; Siem, S; Syed, N U. H.; Toft, H K; Tveten, G M; Wikan, K ^[1]; Goriely, S ^[2]; Algin, E ^[3]; Agvaanluvsan, U ^[4]; Goergen, A ^[5]; Loennroth, T ^[6]; Mitchell, G E ^[7]

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1. Department of Physics/SAFE, University of Oslo, N-0316 Oslo (Norway)
2. Institut d'Astronomie et d'Astrophysique, Universite Libre de Bruxelles, CP 226, 1050 Brussels (Belgium)
3. Department of Physics, Eskisehir Osmangazi University, Meselik 26480 (Turkey)
4. Stanford University, Palo Alto, California 94305 (United States)
5. Dapnia/SPhN, CEA-Saclay (France)
6. Department of Physics/SAFE, Aabo Akademi, FIN-20500 Aabo (Finland)
7. Department of Physics, North Carolina State University, Raleigh, NC 27695 (United States)

The nuclear {gamma}-ray strength function is one of the indispensable inputs needed for reaction-rate calculations, and is particularly important for the neutron-capture cross section. The nuclear physics group at the Oslo Cyclotron Laboratory has developed a method to extract simultaneously nuclear level density and {gamma}-ray strength function from particle-{gamma} coincidence measurements. Data on the strength functions of Sn nuclei as well as for lighter elements are presented. The Sn isotopes all display a resonance-like structure close to the neutron threshold, that could possibly be due to the neutron-skin oscillation mode. This so-called pygmy dipole resonance greatly influences the neutron-capture rates. In the lighter nuclei, an enhancement of the strength function at low {gamma} energies is observed. The possible impact of this increase on Maxwellian-averaged reaction rates has been investigated.

• OSTI ID: 21612057
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1377; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ASTROPHYSICS
BARYON REACTIONS
CAPTURE
CROSS SECTIONS
DIPOLES
ELECTROMAGNETIC RADIATION
ENERGY-LEVEL DENSITY
FUNCTIONS
GAMMA RADIATION
GIANT RESONANCE
HADRON REACTIONS
IONIZING RADIATIONS
ISOTOPES
KINETICS
MULTIPOLES
NEUTRON REACTIONS
NUCLEAR REACTION KINETICS
NUCLEAR REACTIONS
NUCLEAR STRUCTURE
NUCLEON REACTIONS
OSCILLATION MODES
PHYSICS
RADIATIONS
REACTION KINETICS
RESONANCE
STRENGTH FUNCTIONS
TIN ISOTOPES