采用蒙特卡罗方法, 通过MCNP5程序对实验大厅内不同散射体产生的散射贡献及散射中子分布进行了计算。结果表明, 散射中子强度随离开临界中子源距离先呈减小趋势, 在接近大厅墙壁处则出现增加, 呈现明显的“W”形状。同时设计并验证了模拟结果的正确性, 结果表明模拟计算与实验测量结果的趋势相同, 证明了计算结果的可靠性。

By MCNP5 program, we used the Monte Carlo method to calculate the scatter contribution and neutron scattering distribution produced by different scattering bodies in experimental hall. The results show that the scattered neutron intensity decreases with the distance between the critical assembly and the measuring position at first, then increases near the hall walls, forming a ‘W’ shape. The experiments are designed and conducted to verify the correctness of simulation results. The consistency of the calculated results and the measured results demonstrates the reliability of the calculated results.