Systematics of the effective ratio (Γ_n/ Γ_f) of neutron emission and fission partial widths for transcurium nuclei

Abstract

The ratios of neutron emission to fission partial widths averaged over the evaporation cascade, ( Gamma n/ Gamma f), are obtained from an analysis of the experimental cross sections of (HI, xn) reactions. The dependences of ( Gamma n/ Gamma f) on the excitation energy, E*, angular momentum, I, and the number of neutrons emitted, x, are determined in the framework of the statistical model of the decay of excited nuclei. Using these dependences, the experimental data are analysed and the semi-empirical systematics of ( Gamma n/ Gamma f) are obtained. The dependence of the ratio ( Gamma n/ Gamma f) on the nucleon composition of the nucleus is considered in the framework of the liquid-drop model.