A study of the ultra-cold neutron up-scattering at reflection from solid surface

We describe a method and present the results of the measurements of spectral change of stored ultra-cold neutrons and the sub-barrier neutron up-scattering from solid surfaces to the energy range higher than the boundary energy of the sample. The method consists in measuring the neutron absorption curves as a function of UCN storage time and the thickness of the absorbers. The quasi-elastic and inelastic UCN up-scattering probability is determined at room temperature. The neutron spectra are inferred in monochromatic and more detailed approximations.