Development of a Spin-Exchange Optical Pumping-Based Polarized 3He System at the China Spallation Neutron Source (CSNS)Supported by the National Key Research and Development Program of China (Grant No. 2020YFA0406000), the National Natural Science Foundation of China (Grant No. 11875265), the Scientific Instrument Developing Project of the Chinese Academy of Sciences (Grant No. 284(2018)), Guangdong Basic and Applied Basic Research Foundation

Abstract

Polarized 3He neutron spin filters (NSFs) can be used as a vital tool for neutron polarization production and analysis. The China Spallation Neutron Source (CSNS), as one of the major neutron facilities in China, has committed resources to the development of a polarized 3He NSF program to support its growing polarized neutron research. A spin-exchange optical pumping (SEOP)-based polarized 3He system and other necessary hardware for NSF transport has been recently developed. The performance of the system is benchmarked using an in-house developed cell named “Trident”. Neutron beam measurements yield a 3He polarization of 77% with over 200 h of on-beam relaxation time. Combining this newly developed SEOP system with the recently reported cell fabrication station, CSNS is now capable of the fully self-sustained production of 3He NSFs that shall support its future neutron polarization research.