(γ, dnp) reactions in S32, Ca40, Ge70

Abstract A detailed study, up to 31 MeV, of the (γ, np) and (γ, d) reactions in S 32 , Ca 40 and Ge 7 has been carried out, together with the study of the other processes: (γ, n ), (γ, Tn ) (γ, Tn ) E n ≧ 5.5 MeV . A rather flat cross section is found for the (γ, d np ) reaction, peaking presumably above 31 MeV. In the case of S and Ca it is found besides that the neutron spectrum associated with the above reaction is much more energetic than could be explained on the basis of a simple evaporation process. A discussion is given of the possible explanation of the above experimental evidence on the basis of some direct photonuclear process.