On the two modes of cluster emission accompanying nuclear fission

Abstract

We have shown that the “equatorial” α-emission of ternary fission can be considered as the α-decay of the double giant dipole resonance. We show now that the equatorial10Be emission can be interpreted as the10Be-decay of the DGDR. But how can the “polar” α-emission in ternary fission, or the isotropic emission of Be in incomplete fusion reactions such as232Th+4He at 200 MeV, be explained? We recall that the formation of a14C cluster in146Ba fragments is probably responsible for the recently discovered second mode of fission of252Cf, and we assume, in analogy with the146Ba case, that less fragile clusters than carbon clusters are formed in other fission fragments,e.g. O-, Ne- (etc.) clusters in Ce-, Nd- (etc.) fragments, from the valence nucleons of their132Sn core, and that these clusters can be ejected in internal energy-rich collisions of vibrating complex fragment configurations. Several arguments are presented in favour of this new hypothesis. Both modes of cluster emission are new disintegration modes of the fissionfragments themselves.