Facility for the development of the multilayer neutron mirror at KUR

The facility for the development of the multilayer mirror as a device for handling slow neutrons is described. The facility consists of a vacuum evaporation system, a neutron reflectometer and a reflectivity calculation program. The properties of the evaporation are discussed. The neutron reflectometer makes use of the time-of-flight method and can measure the reflectivity down to 10−4. In the reflectivity calculation program, we adopt a neutron optical method with a modified optical potential, in which the contrast between layers is reduced, and the potential around the layer boundary is smoothed. It is shown that with a suitable choice of calculation parameters, experimental reflectivity of a supermirror is well reproduced by the calculation.