$CaSO_4:Tb$ TLD의 제작과 특성에 관한 연구

A Study on Fabrication and Characteristics of $CaSO_4:Tb$ TLD

In this study, the highly sensitive $CaSO_4:Tb$ glass capsule type TLDs are fabricated and their trap parameters are determined. The optimum conditions of fabricating of $CaSO_4:Tb$ phosphor was obtained to be in impurity concentration of Tb 1.0 mol% and sintering of $600^{\circ}C$, 2 hr. The glow curve of $CaSO_4:Tb$ consists of three glow peaks and these peaks are isolated by thermal bleaching method. Activation energy of the three glow peaks measured by the initial rise, the peak shape and the heating rate method are 0.70, 0.87, and 1.03 eV. The frequency factors are $1.76{\times}10^9,\;1.74{\times}10^9$, and $9.77{\times}10^8\;s^{-1}$, and the kinetic orders are 1.12, 1.46, and 1.34, respectively. The isolated glow peaks are fitted by least square method and optimum temperature range of the main peak for radiation dosimetry is $230{\sim}295^{\circ}C$.