Abstract:
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.