To simplify the calculation, some assumptions are considered in the current work. The preequilibrium emission in the first step in the equilibrium process, which is characterized by exciton n = 3 and "never come back, " is considered in the preequilibrium emission process; the alpha emission is only completed with the neutron and proton emission, and the second particle emission is neglected. Under those assumptions, a semiempirical systematics of the cross section for the (n, a) reaction is obtained on the basis of the evaporation and exciton models for the energies ranging up to 20 Me V With...
