Tirage et caractérisation des fibres monocristallines scintillatrices de composition grenat

Abstract

The work of thesis was realized in collaboration with Our laboratory of Crystallography - University frères Mentouri, Constantine1- Algeria, institut lumière - matière ( ILM ) Lyon1- france, the European Center for Nuclear Research (CERN) in Geneva-Switzerland, and the Institute for Scintillation Materials NAS, Kharkov-Ukraine (ISMA), we developed and characterized crystal fibers doped with cerium and praseodymium by micro-pulling down technique. Studies of the scintillation properties of cerium and praseodymium doped garnets, were performed on crystal fibers elaborated by the micro-pulling down growing technique. Aluminates of A3Al5O12 (A = Y or Lu) doped with Ce3+ or Pr3+ ions were synthesized as mono-crystals fibers. The studies carried out by DRX, absorption and emission spectroscopy demonstrate that the YAG and LuAG phases are obtained alone without any other parasitic phases. Measurements of attenuation along the fibers and distribution of the rare earth activator (Ce3+ or Pr3+) gave spatial mapping of the distribution of dopants in the fibers, which made it possible to evaluate the luminous in-homogeneities within the fiber Material as a function of the different growing parameters, which made it possible to evaluate the efficiency of each of the two materials in detecting the gamma rays. The whole of this work clearly shows the potential applications of these two materials.