A high resolution measurement of the ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}(\gamma , p)$ cross section is presented from threshold to 28 MeV. In combination with the known ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}(\gamma , n)$ cross section an estimate of the total absorption cross section is obtained and compared with current theoretical predictions. An estimate of the distribution of the isospin components in the giant dipole resonance shows that isospin splitting and the relative $T_{<}$ and $T_{>}$ strengths are in agreement with predictions.

NUCLEAR REACTIONS ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}(\gamma , p)$, $E_{\gamma }=17.5-28.0\mathrm{}$ MeV; measured beta activation yield with bremsstrahlung, deduced cross section, integrated cross section, comparison with theory, isospin GDR components deduced.

• Received 3 January 1983

DOI:https://doi.org/10.1103/PhysRevC.27.1957