Neutron reflectometers in J-PARC

Neutron reflectometry is one of the powerful tools to investigate surface and interfacial structures of materials in the spatial range from nm to sub-μm. Because hydrogen and deuterium atoms have different scattering length for neutrons, this method can distinguish deuterated materials from normal ones in the mixture of soft-condensed matters, such as polymer blends, bio-mimic membranes, and so on. Also, neutrons have magnetic moment. This enables us to observe magnetic structures in magnetic thin layers which are widely utilized in the field of spintronics. In J-PARC MLF, horizontal and vertical type reflectometers are available. A horizontal type reflectometer SOFIA at BL16 is equipped with two downward neutron beam lines with different angles, 2.22 and 5.71 degrees to the horizontal for investigation of free interfaces. A vertical type reflectometer SHARAKU at BL17 is equipped with a convertible polarized / unpolarized neutron beam line and sample environments including magnets and refrigerators. In this paper, we provide a brief introduction and specifications of these reflectometers, together with some examples taken with them. (author)