Development of the He neutron spin filter at JAEA

Okudaira, Takuya; Oku, Takayuki   ; Sakai, Kenji ; Ino, Takashi*; Hayashida, Hirotoshi*; Hiroi, Kosuke  ; Shinohara, Takenao   ; Kakurai, Kazuhisa*; Aizawa, Kazuya  

The technology development section carries out the development of the neutron polarization device: He Spin Filter. He spin filter is a neutron polarization device composed of polarized He gas and alkali metal encapsulated into a special glass cell. Since a neutron absorption cross section of He has very large spin dependence, a polarized neutron beam can be obtained passing through the polarized He gas. He nuclei are polarized irradiating a circularly polarized laser (Spin Exchange Optical Pumping method). The development of the He spin filter is ongoing in JAEA. A system for the electron paramagnetic resonance, which can measure the He polarization without the neutron beam, was developed. Additionally, a vacuum system to make He spin filter was constructed and the development of high quality He spin filter using Rb and K (Hybrid SEOP) is also ongoing. The current status of the development at JAEA will be presented.