利用Mcstas对两种中子导管模型的模拟计算

Simulation for Two Kinds of Neutron Guide Model by Use of Mcstas Program

对于一台中子散射谱仪,中子导管对中子的传输性能很重要,文中利用Mcstas程序对中子小角散射谱仪中平行中子导管和锥形中子导管以及平行中子导管的几种准直长度对中子的传输性能进行了模拟计算,通过对样品台处束流轮廓和中子注量率的计算,可以看出,相对于锥形中子导管,平行中子导管为中子传输性能更优良的排列模式,平行中子导管模式下几种准直长度具有不同的中子的传输效率,设计时要兼顾准直度和注量率这两个因素。

The transmission characteristic of neutron is very important for the neutron guide of one neutron scattering spectrometer. The parallel and the tapered neutron guides , and the several collimators of the parallel mode of the small angle neutron scattering spectrometer have been simulated in this paper by use of Mcstas. From the flux and the distribution of the sample position, it can be seen that the parallel guide pattern is the better one than the tagered neutron guide. The several collimators of the parallel mode have different efficiency for neutron transmission, and the two factors-collimation and flux of neutron-should be considered at the same time when designing.