JOURNAL OF FUSION ENERGY, vol.32, no.3, pp.336-343, 2013 (SCI-Expanded)
The knowledge of cross section for emission of light charged particles (p, d, t, and alpha) induced by fast neutrons on structural fusion materials has a critical importance on fusion reactors. The gas production arising from (n,p) and (n,alpha) reactions causes seriously radiation damage in fusion reactor structure. The radiation damage in fusion related materials is a large problem need to be overcome for development of fusion reactor technology. Particularly, the (n,alpha) reaction cross section data are required to estimation of the radiation damage effects on structural fusion materials. Therefore, the cross section data for (n,alpha) reaction induced by fast neutrons are of increasing importance for the success of future fusion reactors. In this study, reaction model calculations of the cross sections of neutron induced reactions on structural fusion materials such as (29) Si, (30) Si, (48) Ti, (50) Ti, (50) Cr, (54) Cr, (54) Fe and (58) Fe have been investigated. The new calculations on the excitation functions of (29) Si (n,alpha) (26) Mg, (30) Si (n,alpha) (27) Mg, (48) Ti (n,alpha) (45) Ca, (50) Ti (n,alpha) (47) Ca, (50) Cr (n,alpha) (47) Ti, (54) Cr (n,alpha) (51) Ti, (54) Fe (n,alpha) (51) Cr and (58) Fe (n,alpha) (55) Cr have been carried out for incident neutron energies up to 30 MeV. In these calculations, the pre-equilibrium and equilibrium effects for (n,alpha) reactions have been investigated. The pre-equilibrium calculations involve the new evaluated the geometry dependent hybrid model, hybrid model and the cascade exciton model. The equilibrium effects of the excitation functions for the investigated reactions are calculated according to the Weisskopf-Ewing model. Also in the present work, the (n,alpha) reaction cross sections have calculated by using evaluated empirical formulas developed by Tel et al. at 14-15 MeV energy. The calculated results have been discussed and compared with the available experimental data and found agreement with each other.