Growth and characterization of directionally solidified eutectic systems for scintillator applications

Fabrication of scintillating eutectic composites by various directional solidification techniques is introduced and discussed in some details. Number of methods widely practiced for the single crystal growth including Czochralski, Bridgman or vertical zone melting, and micro-pulling-down are also acceptable for the production of eutectic materials. Two types of such materials are considered here. These are (1) composites used for neutron scintillators; eutectic materials that consist of high neutron cross section material and efficient scintillator (they do not require regular micro-structure) and (2) high resolution scintillators; eutectic materials that have well ordered rod/fiber structure of one of the phases immersed into matrix of second phase (one of them should be efficient scintillator). In later one, the wave guiding can be established in one of the phases (either matrix or fibers). The composites with fiber structure are supposed to be very promising substances for detecting initial irradiation with high spatial resolution. LiF/LiYF₄ and LiF/CaF₂:Eu eutectic composites represent first group of the scintillators, but CsI/NaCl and GdAlO₃/α-Al₂O₃ correspond to the second one.