Thermal processes at growh of non-activated scintillational materials

The object of research is the directed crystallization partly of semitransparent materials from melt. The subject of research is mathematical models of radiation-conductive and radiation-convective heat exchange. Mathematical models and techniques of numeral solution of tasks of ra-diation-convective heat exchange are worked out taking into account influence of impurities in melt on an asorptance and selectivity of optical properties of semitransparent crystal and melt. Dominant influence of radiation heat transfer was shown by researches with the use of simulation of the temperature fields, gradients of temperature, convection and radiation fluxes at the change of crystal-melt system configuration. The row of numeral experiments is conducted at Kiropulos method conditions for growing of alkaline-haloid crystals (in particular, cesium iodide), with the purpose of optimization of this crystal growth method conditions and their comparison with ISM NAS experimental data. The research results of factors influence on the growth thermal processes control allow analysing technological processes and giving recommendation on configuration of heater powers in the crystallizational setting at the scintillation materials production. Methodologies of the optical measuring are modified for an absorptive environment and determination of supercooling at the front of crystallization. mathematical modeling, crystallization, semitransparent material, radiation-conductive heat exchange, finite volumes method, method of discrete ordinates, asorptance, impurity.

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