中子照相转换屏的角度响应研究

在定量中子照相散射校正时需要考虑中子转换屏对不同角度入射中子的响应,中子转换屏的角度响应研究在中子照相散射校正中具有很重要的意义。本文在理论上推导中子转换屏的角度响应的解析式,并利用蒙特卡罗程序MCNP5对该解析式进行验证。利用蒙特卡罗方法对中子转换屏角度响应的影响因素进行研究。给出中子转换屏的角度响应与转换屏厚度以及入射中子能量之间的关系,中子转换屏的角度响应随着转换屏的厚度增大而增大,随着入射中子能量的增大而减小,并得到6LiF-ZnS(Ag)转换屏的最佳厚度为0.3mm。 

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 of6LiF-ZnS (Ag) is 0.3 mm