The12C (γ, n)11C cross-section above the giant resonance

Abstract

The cross-section for the reaction12C(γ, n)11C above the giant resonance has been measured up to 70 MeV of γ-ray energy. The Penfold and Leiss analysis gives a value of the integrated cross-section of (88 ± 7) mb MeV in agreement with the classical dipole sum rule; the contribution between 35 and 70 MeV is about 30 mb MeV,i.e. 34% of the measured integrated (γ, n) cross-section. A wide resonance at about 35 MeV mainly corresponding to 1s12/−11p1/2 transition predicted by the particle-hole calculations has been observed. There is also some evidence of structure at about 53 MeV.