Polarization-Analyzed Small-Angle Neutron Scattering with an $\textit{in-situ}$ $^{3}$He neutron spin filter at the China Spallation Neutron Source
Abstract
Polarization-analyzed small-angle neutron scattering (PASANS) is an advanced technique that enables the selective investigation of magnetic scattering phenomena in magnetic materials and distinguishes coherent scattering obscured by incoherent backgrounds, making it particularly valuable for cutting-edge research. The successful implementation of PASANS in China was achieved for the first time at the newly commissioned Very Small Angle Neutron Scattering (VSANS) instrument at the China Spallation Neutron Source (CSNS). This technique employs a combination of a double-V cavity supermirror polarizer and a radio frequency (RF) neutron spin flipper to manipulate the polarization of the incident neutrons. The scattered neutron polarization is stably analyzed by a specially designed optical pumping He neutron spin filter, which covers a spatially symmetric scattering angle coverage of about 4.8 . A comprehensive PASANS data reduction method, aimed at pulsed neutron beams, has been established and validated with a silver behenate powder sample, indicating a maximum momentum transfer coverage of approximately 0.25 {\AA} .
Keywords
Cite
@article{arxiv.2501.13647,
title = {Polarization-Analyzed Small-Angle Neutron Scattering with an $\textit{in-situ}$ $^{3}$He neutron spin filter at the China Spallation Neutron Source},
author = {Long Tian and Han Gao and Tianhao Wang and Haiyun Teng and Jian Tang and Qingbo Zheng and Taisen Zuo and Tengfei Cui and Bin Wang and Xu Qin and Yongxiang Qiu and Yuchen Dong and Yujie Zheng and Zecong Qin and Zehua Han and Junpei Zhang and He Cheng and Xin Tong},
journal= {arXiv preprint arXiv:2501.13647},
year = {2025}
}