Measurement of the radiative neutron capture cross section of {sup 206}Pb and its astrophysical implications

Journal Article · Mon Oct 15 00:00:00 EDT 2007 · Physical Review. C, Nuclear Physics

DOI:https://doi.org/10.1103/PHYSREVC.76.045805· OSTI ID:21067848

Domingo-Pardo, C ^[1]; Abbondanno, U; Fujii, K; Milazzo, P M; Moreau, C ^[2]; Aerts, G; Andriamonje, S; Berthoumieux, E; Dridi, W; Gunsing, F; Pancin, J; Perrot, L; Plukis, A ^[3]; Alvarez, H; Duran, I; Paradela, C ^[4]; Alvarez-Velarde, F; Cano-Ott, D; Embid-Segura, M; Gonzalez-Romero, E ^[5]

---

1. Forschungszentrum Karlsruhe GmbH (FZK), Institut fuer Kernphysik (Germany)
2. Istituto Nazionale di Fisica Nucleare (INFN), Trieste (Italy)
3. CEA/Saclay - DSM/DAPNIA, Gif-sur-Yvette (France)
4. Universidade de Santiago de Compostela, Santiago de Compostela (Spain)
5. Centro de Investigaciones Energeticas Medioambientales y Technologicas, Madrid (Spain)

The (n,{gamma}) cross section of {sup 206}Pb has been measured at the CERN n{sub T}OF facility with high resolution in the energy range from 1 eV to 620 keV by using two optimized C{sub 6}D{sub 6} detectors. In the investigated energy interval about 130 resonances could be observed, from which 61 had enough statistics to be reliably analyzed via the R-matrix analysis code SAMMY. Experimental uncertainties were minimized, in particular with respect to (i) angular distribution effects of the prompt capture {gamma}-rays, and to (ii) the TOF-dependent background due to sample-scattered neutrons. Other background components were addressed by background measurements with an enriched {sup 208}Pb sample. The effect of the lower energy cutoff in the pulse height spectra of the C{sub 6}D{sub 6} detectors was carefully corrected via Monte Carlo simulations. Compared to previous {sup 206}Pb values, the Maxwellian averaged capture cross sections derived from these data are about 20% and 9% lower at thermal energies of 5 keV and 30 keV, respectively. These new results have a direct impact on the s-process abundance of {sup 206}Pb, which represents an important test for the interpretation of the cosmic clock based on the decay of {sup 238}U.

• OSTI ID: 21067848
• Journal Information: Physical Review. C, Nuclear Physics, Vol. 76, Issue 4; Other Information: DOI: 10.1103/PhysRevC.76.045805; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA). n-TOF Collaboration; ISSN 0556-2813
• Country of Publication: United States
• Language: English

Related Subjects

73 NUCLEAR PHYSICS AND RADIATION PHYSICS
ANGULAR DISTRIBUTION
ASTROPHYSICS
CAPTURE
COMPUTERIZED SIMULATION
CROSS SECTIONS
ELEMENT ABUNDANCE
EV RANGE
GAMMA RADIATION
KEV RANGE
LEAD 206
LEAD 208
MONTE CARLO METHOD
NEUTRON REACTIONS
NEUTRONS
NUCLEAR DECAY
R MATRIX
RESONANCE
S PROCESS
URANIUM 238