CMRR中子自旋回波谱仪引束导管模拟研究  

A simulation study of the deflected neutron guide of neutron spin-echo spectrometer at CMRR

作　　者：王柏桦 黄朝强[1,2] 王亭亭 孙光爱[1,2] 王燕[1,2] WANG Baihua;HUANG Chaoqiang;WANG Tingting;SUN Guang'ai;WANG Yan(Institute of Nuclear Physics and Chemistry,China Academy of Engineering Physics,Mianyang 621999,China;Key Laboratory of Neutron Physics,China Academy of Engineering Physics,Mianyang 621999,China)

机构地区：[1]中国工程物理研究院核物理与化学研究所,绵阳621999 [2]中国工程物理研究院中子物理学重点实验室,绵阳621999

出　　处：《核技术》2020年第3期1-6,共6页Nuclear Techniques

基　　金：国家自然科学基金(No.U1830205);国家重点研发计划(No.2017YFA0403700)资助~~

摘　　要：中国绵阳研究堆(China Mianyang Research Reactor,CMRR)采用由弯导管和直导管组成的引束导管偏转第三条冷中子管(C3)冷中子束第二端口(C32)上部区域内的中子束流,为自旋回波谱仪提供中子束。应用中子射线追踪程序McStas 2.5对引束导管进行蒙特卡罗模拟,从弯导管通道个数、曲率半径以及超镜因子三个方面,考察引束导管设计方案以验证其设计可行性。结果表明:1)弯导管通道个数设计值合理;2)弯导管曲率半径取值在谱仪与屏蔽体安装空间可接受情况下,应尽量大;3)弯导管超镜因子取2.5时,引束导管出口与样品处中子通量可达到最大强度。根据模拟计算结果,弯导管超镜因子设计值偏大,引束导管设计方案总体具有可行性。[Background] Neutron beam is provided for the spin-echo spectrometer at China Mianyang Research Reactor(CMRR) by neutron deflection at the upper part of the C32 exit of the C3 cold neutron guide. The deflected neutron guide consists of curved guide pipe and straight guide pipe with cross-section 30 mm(W) ×30 mm(H).[Purpose] This study aims to validate the design scheme of the deflected neutron guide by simulation. The parameters including the number of the channels of the curved guide, the radius of the curved guide and the supermirror factor of the deflected neutron guide. [Methods] Neutron ray-tracing package McStas version 2.5 was employed to perform Monte Carlo simulation to investigate the effects of the parameters of the deflected neutron guide on the neutron flux, energy spectrum and beam divergence at the exit and sample position of the deflected neutron guide. The parameters of the curved guide pipe such as the number of the channels, the radius, and the supermirror factor of the deflected neutron guide were studied as well. [Results] The results show that: 1) it is reasonable to divide the curved guide into 6 channels vertically;2) the radius of the curved guide should be as large as possible when the space meet the requirements to the installation of the spectrometer;3) the neutron flux is close to the maximum flux while the supermirror is 2.5. [Conclusions] According to simulation results, the design scheme for deflected neutron guide is achievable by using 6 channels with the radius 0 f 40.0 m and the supermirror factor of 2.5.

关 键 词：中国绵阳研究堆 蒙特卡罗模拟 引束导管 弯导管 McStas 

分 类 号：TL817.9[核科学技术—核技术及应用] TL99