Observation of channeling effects for relativistic electrons in a polycrystal

Abstract

Channeling phenomena have been studied extensively, mainly using single crystals as targets. Although the channeling of a low energy ion beam has been used to analyze the structure of polycrystalline materials, there have been few reports on the channeling of relativistic electrons in a polycrystal. In this paper, experimental results are presented for the channeling of 255-MeV electrons in a 10-μm-thick polycrystalline Mo foil. Channeling was observed as a broadening of the transmitted beam at specific foil rotation angles. The range of rotation angles for which channeling occurred was about 3.7°, which was considered to reflect the angular texture distribution in the Mo foil. To confirm this hypothesis, X-ray diffraction measurements were performed on the same Mo foil. The intensity of the {110} reflection was measured as a function of the foil rotation angle. The resulting texture distribution was found to be in fairly good agreement with that obtained in the channeling experiments. The applications of textured polycrystals to beam manipulation techniques and radiation sources are also discussed.