Smooth interfaces of multilayer monochromators

Monochromators used in neutron or X-ray experiments sometimes have unintended higher order contributions. In most cases filters are used to remove them. We sputtered multilayer monochromators with smooth interfaces to reduce the higher order contributions removing the need for a filter. Ni and Ti are selected as sublayer materials due to their high scattering length density contrast. We have strongly reduced the higher order contributions by annealing. This reduces the roughness and off-specular scattering, however the second and third-order Bragg peak intensities increase unexpectedly in neutron reflectivity experiments.