中子小角散射实验及原始数据的处理

中子小角散射技术是研究纳米尺度范围材料结构的有力工具。中子小角散射实验测量和原始数据的处理方法相对较复杂。为了获得样品的绝对中子小角散射强度数据,通常需要进行入射中子束强度、散射强度、样品的透射率、实验本底以及空样品盒的散射强度和透射率等多项实验测量。若要获取较宽散射矢量范围的实验数据,还要改变实验仪器设置,对同一样品进行几次测量。而对所测数据也需要进行多项处理,才可获得便于分析的小角散射强度曲线。本文简单介绍实验原理和测量方法,重点讨论原始数据的处理方法,其中详细讨论了各向同性散射数据的平均以及合并方法。

Small angle neutron scattering experiment and raw data reduction

Small angle neutron scattering (SANS) technique is a powerful tool for nanometer structural analysis of materials. The process of SANS measurement,and the raw data reduction,is relatively complicated. In order to obtain the absolute SANS intensity,one needs to measure intensities of the incident and scattered beams,the sample transmission,the background,the scattering and transmission of the empty cell etc. If a wide scattering vector range is needed,one has to measure the same sample under different instrument configurations. Also,a large number of data treatments are needed before one obtains the SANS data for further analysis. In this paper,after a short introduction to the SANS basic theory and the experimental system,we focus on the raw data reduction method,in which the averaging and the combination of the isotropically scattered data are discussed in detail.