Target dependence of beryllium fragment production in neutron- and alpha-induced nuclear reactions at intermediate energies

Abstract

SummaryThe yields of7Be fromnatC,27Al,natCu,natAg and197Au targets and10Be fromnatCu,natAg and197Au targets in alpha- (400 MeV) and neutron- (maximum end-point energy,E0= 500 MeV) induced reactions were measured in order to compare them with the photonuclear-reaction yields atE0= 1000 MeV. The target-mass dependences of the yields of7Be and10Be showed very similar trends among alpha-, neutron-, and photon-induced reactions. The fragmentation yields of7Be decreased more slowly, and those of10Be increased gradually with an increase in the target mass; both yields intersected at an approximate target mass of 125. The exponential increase in the fragmentation-yield ratios of10Be to7Be with an increase in the neutron-to-proton ratio of the targets suggests that pre-formation of the fragments inside the excited nuclei is strongly influenced by the target properties, such asN/Z. Furthermore, the effect of the incident particle was clearly observed in the yield ratios of10Be to7Be from the Cu and Ag targets.