Gorilets'kyj V. Physical-technical foundations of growing massive alkali halide crystals from melt.

Object of study: growth of big-size pure and doped alkali halide crystals from melt on a seed; study of structural macrodefects, optical and scintillation properties. Purpose of investigation: complex investigation of peculiarities of pure KCl crystallization and effect of single activator centers present in the volume of doped (CsI(Na), NaI(Tl), CsI(CO3), LiF(W)) crystals on their optical and scintillation characteristics. Methods of study and equipment: luminescent and optical spectroscopy, spectrophotometers "Specord M-40", UR-20, laser-calorimetric set-up, installation for crystal growth "Rost". Theoretical and practical results, novelty: physical-technical foundations of the method for growing big-size alkali halide crystals with a specified dislocation structure and controlled optical, scintillation and mechanical characteristics have been created. An instrumental-technical complex has been designed, tested and implemented to practice. Methods of study and equipment: luminescent and optical spect roscopy, spectrophotometers "Specord M-40", UR-20, laser-calorimetric set-up, installation for crystal growth "Rost". Degree of application in industry: introduced in industrial production have been highly transparent optical KCl crystals up to 600 mm in diameter, NaI(Tl), CsI(Na) crystals 520 mm in diameter having higher and more uniform scintillation parameters, techniques of straight and curvilinear cutting of crystals by a directed dissolution for cutting big crystals into blanks of different shape which have low roughness of the surface and the corresponding technological equipment. Field of application: optical and scintillation material research science.