Tenue sous irradiation de multicouches NixC1-x/Ti

Nous présentons ici les résultats de l'étude du vieillissement sous irradiation aux neutrons thermiques de multicouches NiC/Ti utilisées dans la fabrication des supermiroirs pour guides de neutrons. Nous montrons que le titane subit, sous irradiation, un changement de phase avec ou sans formation d'hydrure. De plus, les contraintes dans le nickel varient en fonction des taux d'irradiation

Titanium Evolution Under Neutron Irradiation in NixC1-x/Ti Multilayers

Supermirrors, which are NixC1-x/Ti aperiodic multilayers, have become more and more important for use in neutron guides. The effects of neutron radiation on the structural and optical properties of such stacks have been studied to estimate the lifetime of the neutron guides. The results presented here have been obtained by neutron reflectivity, X-ray diffraction, Conversion-Electron Extended X-ray Absorption Fine Structure and High Resolution Transmission Electron Microscopy. It has been observed that the reflecting performances of the supermirrors were not altered by irradiation, but that a structural change did occur in the Ti layers