Measurement of the {sup 151}Sm(n,{gamma}) cross section from 0.6 eV to 1 MeV via the neutron time-of-flight technique at the CERN n{sub T}OF facility
- Dipartimento di Fisica and INFN Bari (Italy)
- Instituto Nazionale di Fisica Nucleare Sezione di Trieste (Italy)
- CEA/Saclay-DSM/DAPNIA/SPhN, Gif-sur-Yvette (France)
- Centro de Investigaciones Energeticas Medioambientales y Tecnologicas, Madrid (Spain)
The {sup 151}Sm(n,{gamma}) cross section was measured with the time-of-flight technique from 0.6 eV up to 1 MeV relative to the Au standard with an overall uncertainty of typically 6%. Neutrons were produced by spallation at the innovative n{sub T}OF facility at CERN; the {gamma} rays from capture events were detected with organic C{sub 6}D{sub 6} scintillators. Experimental setup and data analysis procedures are described with emphasis on the corrections for detection efficiency, background subtraction, and neutron flux determination. At low energies, resonances could be resolved up to about 1 keV, yielding a resonance integral of 3575{+-}210 b, an average s-wave resonance spacing of <D{sub 0}>=1.49{+-}0.07 eV, and a neutron strength function of <S{sub 0}>=(3.87{+-}0.33)x10{sup -4}. Maxwellian-averaged capture cross sections are reported for thermal energies between 5 and 100 keV. These results are of relevance for nuclear structure studies, nuclear astrophysics, and nuclear technology. The new value of the Maxwellian-averaged cross section at kT=30 keV is 3.08{+-}0.15 b, considerably larger than previous theoretical estimates, and provides better constraints for the thermodynamic conditions during the occurrence of the slow neutron capture process in low-mass stars during their asymptotic giant branch phase.
- OSTI ID:
- 20771351
- Journal Information:
- Physical Review. C, Nuclear Physics, Vol. 73, Issue 3; Other Information: DOI: 10.1103/PhysRevC.73.034604; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2813
- Country of Publication:
- United States
- Language:
- English
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