The 98° differential cross sections for the reactions 13C(γ,n0)12C and 13C(γ,n1)12C

Abstract

The differential cross sections at 98° for the reactions 13C(γ,n0)12C and 13C(γ,n1)12C were measured over the range of 6.0 to 37.0 MeV and 10.5 to 35.5 MeV, respectively. The cross sections are compared with previous results on the same nucleus or results from the similar reaction 12C(p,γ0)13N. In the region of the so-called pygmy resonance (about 13.5 MeV) there are many sharp resonances which correspond very well with the level structure of 13C as deduced from several other studies using various reactions. For the full energy region studied, further evidence for the isospin splitting of the 13C photoneutron cross section is obtained. In comparison of the cross sections with recent theoretical results, general agreement is obtained. However, several details of this comparison are in disagreement; the implications of this disagreement are discussed.