Neutron mirror with magnetic repulsive wall

Fuwa, Yasuhiro   ; Kuriyama, Yasutoshi*; Iwashita, Yoshihisa*; Hirota, Katsuya*; Yamada, Masako*; Kitaguchi, Masaaki*; Shimizu, Hirohiko*

A neutron mirror with a magnetic repulsive wall is under development. Since neutrons have a magnetic dipole moment, they are subject to forces in a magnetic field gradient. Using this phenomenon, a potential wall for neutrons can be formed by arranging permanent magnets in a planar configuration of a Halbach array. This potential wall acts as a mirror for a polarized neutron beam. A prototype mirror 20 mm high and 30 mm wide was fabricated, and preliminary neutron reflection experiments were conducted at the MINE2 port of JRR-3. As the next step, we plan to fabricate a mirror with a larger size and conduct experiments at the J-PARC MLF. In this presentation, the principle of the mirror, the results of preliminary experiments at JRR-3, and the status of the mirror fabrication for the experiment at J-PARC will be reported.