SUPERMIRRORS STUDY BY NEUTRON MULTIREFLECTION

We present here time of flight neutron multireflection measurements. T his technique has been developed at the Laboratoire Leon Brillouin (Sa clay-France). Used in the investigation of supermirrors NiC/Ti, it all ows us to increase the precision of the measurement of the most import ant part of the curve for technological applications : the extension o f the total reflection plateau. The results on three systeMS (Ni-58 si ngle layer, multilayer NiC/Ti, supermirror NiC/Ti) are presented in th is 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, multireflectio n experiment enables us to increase the accuracy of the reflectivity v alue measured on the extended plateau.