Studies of ways to reduce defects in CdWO_4j signle crystals

摘要

Studies are reported of the nature and fomtion conditions of strucutral defects affecting principal working characteristics of cadmium tungstate single crystlas (macro- and microinclsions, scattering centers, block structure, twinning, violations of stoichiometry). It is shown tha macro- and microinclsions re morphoogically related to the crystal gowth from the supercooled melt and are cuased by the caputre of crystal-formating components as intrinsicj impurities by the growing crystal. Macro- and microinclusions are shown to form layered structures paralell to the (1 0 0) planes, which are also twinning planes. Ways are proposed to improe structural perfection of the crystals, providing for their hgih functional characteristics. Accounting for the studied features of intrinsic defect formation, optimm crystallogrpahic direcions were suggested for the crystal growth and subseuent cutting into scintillation elemens with high and reproducible funcional characteristics.