材料与构件深部应力场及缺陷无损探测中子谱仪热中子导管概念设计

Conceptual Design of Thermal Neutron Guide of Neutron Diffractometer for Residual Stress Field and Defect in Material and Component

针对中国先进研究堆(CARR)正在建造的材料与构件深部应力场及缺陷无损探测中子谱仪所需的热中子导管,开展模拟计算与概念设计。首先根据CARR内的现场情况和该谱仪的整体要求设计热中子导管的内部截面尺寸为90 mm×160 mm,整体长度为19.7 m,导管长度分为3组;然后根据这些参数开展蒙特卡罗模拟,通过比较导管镀层的特征增殖因数m分别为1、2、3、4、5、6时导管末端的中子强度二维空间分布、水平方向发散角分布、波长分布等主要性能指标的模拟结果,选定m=3,并以此完成了导管的参数设计。

The simulation calculation and conceptual design of the thermal neutron guide for the neutron diffractometer for residual stress field and defect in materials and components being constructed on China Advanced Research Reactor(CARR) were carried out. Firstly, according to the ambient conditions in the CARR and the overall requirements of the diffractometer, the internal section size of the thermal neutron guide was designed to be 90 mm×160 mm, the overall length of the guide was 19.7 m, and the length of the guide was divided into three sections. Then, according to these parameters, Monte Carlo simulation was carried out. Based on the simulation results of performance output such as horizontal neutron angular distribution, two-dimensional neutron spatial distribution and wavelength distribution, the characteristic multiplication factor of neutron guide m=3 was selected. The parameters of the guide were also designed.