(3He, xn), (3He, pxn) and (3He, fission) reactions on 206Pb between 80 and 200 MeV

Abstract

The reactions induced in 206Pb by 3He particles having energies between 80 and 200 MeV have been studied. Excitation functions for (3He, xn) with x = 3 to 14 and for (3He, p xn) with x = 2 to 5 have been obtained. Angular distributions of fission fragments were measured at 100, 125, 150 and 175 MeV and total fission cross-sections were deduced from the data. On the basis of these results, analysis is attempted to examine the characteristics of reaction mechanisms. From these results we get the conclusion that non-compound processes play an important role in the reactions. Two features are characteristic of these processes : large cross-sections for charged particle emission and angular distribution of fission fragments closed to isotropy in the laboratory system. In the energy range 25 to 45 MeV/nucleon, a comparison was made between the present results and those from an experimental study of α-particle induced reactions on 206Pb. Also a comparison was made with an α-nucleus collision model applied to 206Pb. All the observations strongly suggest a breakup of the projectile 3He followed by the interactions of the fragments with the target nucleus.