装置极化效率对极化中子成像质量的影响及修正分析  

Effect of apparatus polarization efficiency on quantification analysis in polarized neutron imaging

作　　者：曹超[1] 李航[1] 霍合勇[1] 唐科[1] 孙勇[1] 

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621900

出　　处：《物理学报》2013年第16期63-69,共7页Acta Physica Sinica

基　　金：国家自然科学基金青年科学基金(批准号:11205138);中国工程物理研究院科学基金(批准号:2012130103004)资助的课题~~

摘　　要：极化中子照相技术通过分析极化中子束的自旋相移对样品磁场进行成像,自旋极化/分析装置是照相系统的主要组成部分.引入中子自旋极化/分析装置的极化效率参数,从中子极化矢量与磁场相互作用机理出发,重新推导探测中子强度与磁场分布的定量关系,利用谱仪模拟软件VITESS,选取bender型超镜极化器和3He自旋过滤器作为极化/分析装置,对量化修正式进行验证,并综合装置极化效率、单色器能量分辨精度和bender型极化器的几何结构等参数,初步分析极化中子照相技术的磁场定量检测能力,相关结果可为极化中子照相的实验数据处理技术研究及装置设计提供参考.Polarized neutron radiography allows the direct and real-space visualization of magnetic field distribution by detecting the polarization change in the transmitted beam. Spin polarizer/analyzer apparatus is important in polarized neutron imaging system, whose polarization efficiency directly affects the imaging quality of magnetic field. In this paper, the relation between the registered neutron intensity and magnetic field distribution is re-calculated after introducing the polarization efficiency parameter. Bender polarizers and 3He spin filters are simulated by Monte Carlo software VITESS to verify the calculation. The quantification ability with low beam polarization is also analyzed by considering the beam monochromaticity and bender geometry. The results will be helpful for processing image data and designing instrument.

关 键 词：极化效率 中子照相 磁场成像 

分 类 号：O571.5[理学—粒子物理与原子核物理]