TED-AJ03-517 ANALYSIS OF TEMPERATURE DISTRIBUTION IN A SEMI-TRANSPARENT CRYSTAL DURING CZOCHRALSKI SINGLE-CRYSTAL GROWTH

概要

論文の詳細を見る
Gd_2SiO_5 (GSO) single-crystal is widely used for sensors in positron emission computed tomograhy, etc. Temperature distributions in a semi-transparent GSO crystal during Czochralski single-crystal growth were numerically investigated by two-dimensional axisymmetric heat-transfer analysis of thermal radiation and conduction. Since the properties of the GSO crystal and melt change from transparent to opaque at a wavelength of 4.5 μm, the band-energy approximation was used in the analysis. The results showed that the upper part of an insulator in a Czochralski apparatus was heated by thermal radiation energy at the so-call transparent wavelength (at a wavelength shorter than 4.5 μm) from inside of a heated crucible, and the peripheral of the upper part of the insulator. Temperature distributions in the crystal were calculated by changing the border wavelength (between transparent and opaque of the crystal). Longitudinal temperature distribution was maximum when the border wavelength was 4.5 μm. Peripheral temperature of the crystal at the solid-liquid interface decreased when the border wavelength was short (that is, average transmittance is low). [figure]
一般社団法人日本機械学会の論文