Neutron physics of the Re/Os clock. I. Measurement of the (n,gamma) cross sections of {sup 186,187,188}Os at the CERN n{sub T}OF facility

Journal Article · Thu Jul 15 00:00:00 EDT 2010 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.82.015802· OSTI ID:21389230

Mosconi, M; Kaeppeler, F; Audouin, L; Dillmann, I; Heil, M; Plag, R; Voss, F; Walter, S; Wisshak, K ^[1]; Fujii, K; Abbondanno, U; Belloni, F; Milazzo, P M; Moreau, C ^[2]; Mengoni, A ^[3]; CERN, CH-1211 Geneva ^[4]; Domingo-Pardo, C ^[1]; Aerts, G; Andriamonje, S; Berthoumieux, E ; Dridi, W ^[5]

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1. Karlsruhe Institute of Technology (KIT), Campus Nord, Institut fuer Kernphysik, D-76021 Karlsruhe (Germany)
2. Istituto Nazionale di Fisica Nucleare, I-34149 Trieste (Italy)
3. International Atomic Energy Agency, NAPC-Nuclear Data Section, A-1400 Vienna (Austria)
4. Switzerland
5. CEA/Saclay, DSM, F-91191 Gif-sur-Yvette (France)

The precise determination of the neutron capture cross sections of {sup 186}Os and {sup 187}Os is important to define the s-process abundance of {sup 187}Os at the formation of the solar system. This quantity can be used to evaluate the radiogenic component of the abundance of {sup 187}Os due to the decay of the unstable {sup 187}Re (t{sub 1/2}=41.2 Gyr) and from this to infer the time duration of the nucleosynthesis in our galaxy (Re/Os cosmochronometer). The neutron capture cross sections of {sup 186}Os, {sup 187}Os, and {sup 188}Os have been measured at the CERN n{sub T}OF facility from 1 eV to 1 MeV, covering the entire energy range of astrophysical interest. The measurement has been performed by time-of-flight technique using isotopically enriched samples and two C{sub 6}D{sub 6} scintillation detectors for recording the prompt gamma rays emitted in the capture events. Maxwellian averaged capture cross sections have been determined for thermal energies between kT=5 and 100 keV corresponding to all possible s-process scenarios. The estimated uncertainties for the values at 30 keV are 4.1, 3.3, and 4.7% for {sup 186}Os, {sup 187}Os, and {sup 188}Os, respectively.

• OSTI ID: 21389230
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 82, Issue 1; Other Information: DOI: 10.1103/PhysRevC.82.015802; (c) 2010 The American Physical Society; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ABUNDANCE
ASTROPHYSICS
CAPTURE
CERN
COVERINGS
CROSS SECTIONS
EV RANGE
GAMMA DECAY
GAMMA RADIATION
ISOTOPE RATIO
KEV RANGE
NEUTRON REACTIONS
NEUTRONS
NUCLEOSYNTHESIS
OSMIUM 186
OSMIUM 187
OSMIUM 188
PARTICLE DECAY
RHENIUM 187
S PROCESS
SCINTILLATION COUNTERS
SOLAR SYSTEM
TIME-OF-FLIGHT METHOD
ALPHA DECAY RADIOISOTOPES
BARYON REACTIONS
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
DECAY
DIMENSIONLESS NUMBERS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ENERGY RANGE
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
EVOLUTION
FERMIONS
HADRON REACTIONS
HADRONS
HEAVY NUCLEI
INTERNATIONAL ORGANIZATIONS
IONIZING RADIATIONS
ISOTOPES
MEASURING INSTRUMENTS
NUCLEAR DECAY
NUCLEAR REACTIONS
NUCLEI
NUCLEON REACTIONS
NUCLEONS
ODD-EVEN NUCLEI
OSMIUM ISOTOPES
PHYSICS
RADIATION DETECTORS
RADIATIONS
RADIOISOTOPES
RHENIUM ISOTOPES
STABLE ISOTOPES
STAR EVOLUTION
SYNTHESIS
YEARS LIVING RADIOISOTOPES