Photodisintegration of quasi-alpha-particles in the nuclei /sup 6,7/Li by. gamma. rays with E/sub. gamma. /=35--55 MeV

Results are presented of an experimental study of reactions of the type /sup 6,7/Li (..gamma.., ab) X with emission of charged particles a and b detected in coincidence. It is established that the major part of such reactions are reactions of the type /sup 6,7/Li (..gamma..,pt) X. The results of measurement of the correlations of the directions of emission and energy distributions of protons and tritons are explained on the basis of the assumption of photodisintegration of ..cap alpha.. clusters in the ground state of the nuclei /sup 6,7/Li into a proton and triton and of formation of the residues X in the form of two (d+n) particles in reactions /sup 6/Li (..gamma.., pt) X, and two (d+n) particles and possibly three (n+p+n) particles in reactions /sup 7/Li (..gamma.., pt) X. The value of the average differential cross section of the reaction /sup 6/Li (..gamma.., pt) /sup 1/Hn in the ..gamma..-ray energy interval 35--55 MeV amounts to 0.7 +- 0.2 of the value of the cross section for the reaction /sup 4/He (..gamma.., p) /sup 3/H. It is shown that in addition, three-particle reactions of the type /sup 6/Li (..gamma..,td) /sup 1/H and /sup 7/Li (..gamma.., tt) /sup 1/H occur,more » but with a kinematics differing from that of the photodisintegration of ..cap alpha.. clusters, and also two-particle reactions of the type /sup 6/Li (..gamma.., t) /sup 3/He and /sup 7/Li (..gamma.., t) /sup 4/He.« less