고감도 CaSO_4 : Dy TL 분말의 TL 특성 및 고감도 TL 소자 제작 Dy TL powder and development of high sensitivity CaSO_4 Dy TL pellet = TL characteristics of CaSO_4

다국어 초록 (Multilingual Abstract)

CaSO_4 : Dy series TL material is widely used as a personal dosimeter because of its high sensitivity to radiation. KAERI(Korea Atomic Energy Research Institute) has been produced CaSO_4 TL powder activated by Dy(rare earth elements) for several years and continually tried to improve its sensitivity having more than that of commercialized Teledyne CaSO_4 : Dy TL powders(USA). The TL powder is prepared by adding 0.1mol% Dy as an activator and by the acid evaporation method at first. And new step of washing this powder by distil-water is appended to separate non-crystalized powder in the initial crystal of CaSO_4 : Dy powder. CaSO_4 : Dy crystal TL powder which is produced by applying this new method has higer sensitivity than before washing step, and it has also higher sensitivity than that of Teledyne CaSO_4 : Dy TL powder. This CaSO_4 : Dy TL powder shows good TL characteristics such as dose response, energy response and fading. It is not possible to make solid detectors of only CaSO_4 : Dy TL phosphor without any binding material. Until now widely used sintered pellets. which were made from a mixture of CaSO_4 : Dy TL phosphor and Teflon. But, due to reduction in content of CaSO_4 : Dy TL phosphor in pellets(15∼20wt%) the TL sensitivity of pellets was reduced correspondingly. To variously use the CaSO_4 : Dy TL phosphor, research for preparing detectors by mixing CaSO_4 : Dy TL phosphor with different binding substances has been conductedThis paper described development of a new type of CaSO_4 : Dy pellets by using P-compounds as a bonding material(KCT-300), and compared the TL sensitivity with that of the commercialized Teledyne CaSO_4 : Dy pellets. Sensitivity of a new developed KCT-300 shows about 6 times than Teledyne ones, and can be used to measure very low radiation dose.