Photofission of quasi alpha particles in sup(6, 7)Li nuclei by gamma radiation at Esub(γ)=35-55 MeV

Results of experimental investigation of the sup(6, 7)Li(γ,ab)X reactions with emission of a and b charged particles, detected by coincidences, are presented. It is established that the main part of such reactions are the sup(6, 7)Li(γ, pt)X reactions. The measured results on correlations of the emission directions and the energy distributions of protons and tritons are explained basing on the assumption that the α clusters in the ground state of sup(6, 7)Li disintegrate into proton and triton, while the residual state is two-particle (n+p) in the case of the 6Li(γ, Pt)X reactions. The mean differential cross section of the 6Li(γ, pt)1Hn reaction in the γ-energy interval 35-55 MeV amounts to 0.7+-0.2 of the cross section for the 4He(γ, p)3H reaction. It is shown that the three-particle 6Li(γ, td)1H and 7Li(γ, tt)1H reactions also proceed, but with a kinematics, different from that for the fotofission of the α clusters. The two-particle 6Li(γ, t)3He and 7Li(γ, t)4He reactions are also observed