出版社:SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要:Resonance cross sections relevant for the termination of the s-process reaction path have been
determined for 204,206,207Pb and 209Bi at the CERN neutron time-of-flight spectrometer n_TOF.
Themeasurementswere carried out in the neutron energy range from1 eV up to 500 keV. By using
a system of C6D6-detectors with optimized neutron sensitivity, the main corrections of previous
measurements related to backgrounds from scattered neutrons could be practically eliminated.
Other corrections were thoroughly treated by control measurements with additional samples for
determination of the ambient background and of background from in-beam g -rays as well as by
detailed analyses via Monte Carlo simulations. The Maxwellian averaged cross sections of the
four isotopes and their implications for the s-process abundance contributions in the Pb/Bi region
are discussed.