The neutron capture cross sections of 204Pb and 206Pb have been measured at the CERN n_TOF installation using the time of flight method with the pulse height weighting technique. Main improvements versus previous measurements concern the capture experimental setup, which has been optimized in terms of low neutron sensitivity. In the analysis of 204Pb we report new capture cross sections for two strong s-wave resonances below 2.5 keV, which enhance the Maxwellian Average Cross Section at kT = 5 keV by about a factor of two with respect to the recommended values. In 206Pb we have determined new capture cross sections for a large number (97) of resonances, which were not observed in previous measurements. We discuss preliminary implications of the new cross sections in the stellar nucleosynthesis of the Pb isotopes.
Measurement of the Resonance Capture Cross Section of 204,206Pb and Termination of the s-process
Ventura, A.;
2005-09-04
Abstract
The neutron capture cross sections of 204Pb and 206Pb have been measured at the CERN n_TOF installation using the time of flight method with the pulse height weighting technique. Main improvements versus previous measurements concern the capture experimental setup, which has been optimized in terms of low neutron sensitivity. In the analysis of 204Pb we report new capture cross sections for two strong s-wave resonances below 2.5 keV, which enhance the Maxwellian Average Cross Section at kT = 5 keV by about a factor of two with respect to the recommended values. In 206Pb we have determined new capture cross sections for a large number (97) of resonances, which were not observed in previous measurements. We discuss preliminary implications of the new cross sections in the stellar nucleosynthesis of the Pb isotopes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
