Development of neutron supermirrors with large critical angle

Abstract Neutron supermirrors have become important devices for transporting, bending, and focusing neutron beams. For the production of these devices, an ion beam sputtering (IBS) apparatus with an effective deposition area whose diameter is 500 mm has been installed in the Japan Atomic Energy Agency. Ni/Ti supermirrors have been fabricated with high reflectivity extending up to m = 3, 4, and 6.7 times the critical edge of nickel. Their reflectivities at the effective critical momentum transfer were 0.82, 0.66, and 0.23, respectively.