Photoneutron cross sections forC14

The photoneutron cross sections for ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$ [σ(γ,1n) and σ(γ,2n)] have been measured up to 36 MeV using monochromatic photons. The cross section for the emission of a single neutron displays a very prominent resonance near 15 MeV which appears to decay primarily to the ground state of ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$. The (γ,2n) cross section is sharply peaked at 26 MeV and is large compared with those for ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ and ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$. The integrated total photoneutron cross section up to 36 MeV is 126±12 MeV mb (61% of the Thomas-Reiche-Kuhn sum-rule value). The ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$ photoneutron cross sections are interpreted in terms of the reaction kinematics and the competition among the particle channels in order to provide information on the isospin properties of the major E1 states in ${}_{}{}^{14}{}_{}{}^{}\mathrm{C}$ and on the validity of the weak core-coupling model.