Cross Section for the Astrophysical ~14C(n,γ)~15C Reaction via the Inverse Reaction

摘要

The ~14C(n,γ)~15C reaction is important in neutron-induced CNO cycles of stellar evolution phases beyond the main sequence. The chain of reactions in primordial nucleosynthesis in the neutron-rich environment of an inhomogeneous big bang also involves the ~14C(n,γ)~15C reaction. We have used a beam of ~15C ions at E/A = 35 MeV to measure cross sections for ~15C breakup on targets of C, Al, Zn, Sn, and Pb. The Coulomb part of the breakup cross section was determined as a function of decay energy. By the principle of detailed balance, the neutron capture cross section was then determined as a function of neutron energy. This excita- tion function rises with energy to 7 μbarns at 300 keV and falls to 2 μbarns at 1.2 MeV.