Growth of rare earth scintillation crystals with low cost

Abstract

The invention provides a calculating method of growing parameters in a rare earth scintillation crystal growing process and a growing process of rare earth scintillation crystals. The growing process comprises the following steps: firstly, mixing an oxide raw material for preparing the rare earth scintillation crystals to obtain a mixed raw material; then in a vacuum atmosphere or a protective atmosphere, sintering the mixed raw material obtained in the step to obtain a polycrystal material block; and finally, in the vacuum atmosphere or the protective atmosphere, after melting the polycrystal material block, performing crystal growth by means of a pulling method according to the growing parameters calculated by the calculating method guided by seeds with specific growing directions to obtain the rare earth scintillation crystals. From the aspect of a crystal growing theory, the growing parameters such as the fastest growth rate, pulling growth rate and crystal rotating rate thermodynamically permitted through special simulating, deducing and calculating methods are obtained. The growing process is low in energy consumption, little in noble metal loss, short in time of growing process and high in crystal rate of finished products and has an obvious low cost advantage.

Description

technical field [0001] The invention relates to the technical field of scintillation crystal materials, in particular to the growth of low-cost rare earth scintillation crystals. Background technique [0002] Scintillation crystals refer to crystals that can convert the kinetic energy of high-energy particles into light energy and emit flashes under the impact of high-energy particles such as X-rays and radiation. Scintillation, on the other hand, refers to a radioluminescent process that converts high-energy rays or particles into pulses of ultraviolet or visible fluorescence. Scintillation crystals are an important conversion medium that can convert high-energy rays / particles into fluorescent pulses in the near-ultraviolet / visible range. Therefore, they have excellent ionizing radiation detection functions and are currently widely used in high-energy physics, nuclear physics, nuclear medicine imaging, security Inspection, industrial exploration and other important fields....

AI Technical Summary

Problems solved by technology

[0005] However, in the growth process of rare-earth scintillation crystals, such as the growth of cerium-doped yttrium-lutetium silicate (Ce:LYSO) scintillation crystals, the main problems are: 1) the melting point of rare-earth silicate scintillation crystals is high (2050 ° C), which is relatively The high melting point will cause the medium / high frequency power supply to consume high power during the heating process; 2) The melting point of the rare earth silicate scintillation crystal is close to the melting point of the heating body Ir crucible (2450°C), and the Ir volatilization is serious, and the growth period is long Serious loss of precious metals

3) The seed crystal is easy to fuse. The seed crystal is easy to be blown during the seeding process, resulting in failure of crystal growth. The seed crystal is reinstalled after cooling down and opening the furnace, which seriously wastes electric energy and precious metal loss; 4) The crystal is easy to crack. To prevent rare earth silicate The scintillation crystal cracks and its growth rate decreases, resulting in a long growth cycle and high labor costs during the growth process

[0006] To sum up, in the crystal growth process, high energy consumption, serious loss of precious metals, high labor costs in the growth process, and low crystal yield make the growth cost of rare earth silicate scintillation crystals high.

In addition, the high cost of high-purity rare earth raw materials also greatly increases the cost of rare earth scintillation crystals

[0007] Therefore, the high cost of rare earth scintillation crystals has become a shackle in its application field, which hinders its further application in the detection field. How to obtain a low-cost rare earth scintillation crystal growth process has become an urgent problem for frontier scholars in the application field. The problem

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