Direct capture in the 130Sn(n,γ )131Sn and 132Sn(n,γ )133Sn reactions under r-process conditions

摘要

The cross sections of the 130Sn(n,γ )131Sn and 132Sn(n,γ )133Sn reactions are calculated in the direct capturenmodel at low energies below 1.5 MeV. Using recent data from (d,p) transfer experiments on 130Sn and 132Sn, itnis possible to avoid global input parameters with their inherent uncertainties and to determine all inputs to thendirect capture model by local adjustments. The calculated direct capture cross sections of 130Sn and 132Sn arenalmost identical and have uncertainties of less than a factor of 2. The stellar reaction rates NAnu0002σvu0003 show a slightnincrease with temperature. Finally, an estimate for the influence of low-lying resonances to the stellar reactionnrates is given.