Multilayer Neutron Polarizing Mirrors Working Under a Low External Magnetic Field Less Than 100 Gausses

Article type: Research Article

Authors: Kawai, Takeshi | Ebisawa, Toru | Tasaki, Seiji | Eguchi, Yoshiaki | Hino, Masahiro | Achiwa, Norio

Affiliations: Research Reactor Institute Kyoto University, Kumatori-cho, Osaka 590-04, Japan | Department of Physics, Kyushu University, Fukuoka 812, Japan

Abstract: We have developed multilayer neutron polarizing mirrors which are controlled under an external magnetic field less than 100 gausses. Multilayers of Permalloy-Ge and Fe-Ge have been evaporated on Si wafers in the magnetic field of about 130 gausses parallel to the surface of the wafer. The polarizing efficiencies of Fe-Ge and Permalloy-Ge multilayer mirrors were 95% and 91% respectively under a low external magnetic field of 80 gausses. Under a very low external field of 50 gausses, the polarizing efficiency was 90% in case of Permalloy-Ge. A neutron pulse was obtained by applying a pulsed magnetic field of about 50 gausses parallel to the Permalloy-Ge polarizing mirror. The pulse rise time is the order of 100 μs in the present pulsed magnetic devices.

DOI: 10.1080/10238169708200218

Journal: Journal of Neutron Research, vol. 5, no. 3, pp. 123-132, 1997