Angular Dependence Study of the Conversion Screen for Neutron Radiography

In a correction of the scattered effects in quantitative neutron radiography, the angular dependence study of the conversion screen for neutron radiography is very significance. In the paper a simplified analytic expression of the angular dependence has been derived. The mothed of Monte Carlo have been used for proving the analytic expression. The codes of MCNP5 also have been applied for studying the influence factors which are the thickness of the conversion screen for neutron radiography and the energy of the neutron. The functions of the influence factors and the angular dependence have been given by graphs. From the graphs the experience of the angular dependence will be gain when the thickness of conversion rising has been found. But when the energy of the neutron becomes larger the angular dependence will be smaller. The best thickness of the conversion screen which is made of ⁶LiF-ZnS (Ag) is 0.3 mm