Supermirrors study by neutron multireflection

Abstract
We present here time of flight neutron multireflection measurements. This technique has been developed at the Laboratoire Léon Brillouin (Saclay-France). Used in the investigation of supermirrors NiC/Ti, it allows us to increase the precision of the measurement of the most important part of the curve for technological applications : the extension of the total reflection plateau. The results on three systems (⁵⁸Ni single layer, multilayer NiC/Ti, supermirror NiC/Ti) are presented in this paper. Beyond the good quality of the mirrors, they demonstrate the very good reliability of such a measurement. Moreover, they show that compared to a classical single reflection measurement, multireflection experiment enables us to increase the accuracy of the reflectivity value measured on the extended plateau.