• Journal of radiological science and technology
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• v.1 no.1
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• pp.15-24
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• 1978

The characteristics of the rare earth phosphors intensifying screen (LM-6, Grenex-8) as compared with $CaWO_4$ intensifying screen had been studied utilizing several common x-ray films, and found the following results. 1. Compared with the conventional CaWO4 intensifying screen, the rare earth phosphors intensifying screen was found to be more sensitive over to 1.26-3.47 times. So the radiation exposure could be reduced to 1/1.26 -1/3.47. 2. Sharpness as well as the film speed were both increased. So the motion blurring and geometrical unsharpness could be decreased. 3. In spite of that the film speed was increased, photographic contrast was kept up. Therefore, the more ideal film of greater latitude could be obtained. 4. The effects of the rare earth phosphors intensifying screen would be much increased as using with orthochromatic x-ray films.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.859-863
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• 2023

In this study, simple and portable radiation detection system using X-ray intensifying screen, optical sensor and micro-controller unit for education was proposed. The system was simply composed of detection unit consisting of an optical sensor and intensifying screen, micro-controller unit, and was designed to be suitable for portable. Radiation was measured using developed detection system and absorbed dose dosimeter with changing tube voltage from 50 to 100 kVp. The tube current and SDD were fixed on 100 mAs and 100 cm, and dose were measured repeated ten times at each tube voltage. The response and linearity of the detection system were confirmed using the measured values. It was confirmed that the comparison measurement results of the detection system and absorbed dose dosimeter showed a high correlation(r : 0.998, p<.001). In this results, the feasibility of the detection system with intensifying screen and micro-controller unit based was confirmed, and we considered that the developed detection system could be applied to portable, compact, low cost system for education.

• Journal of radiological science and technology
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• v.10 no.1
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• pp.13-23
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• 1987

Author has studied for finding the method of decreasing the radiation dose and increasing diagnostic range in chest X-ray radiography. The study for the added filter thickness from half value layer to 1/8 value layer by decreasing curve and research for the exposure factors, decreasing ratio of radiation dose, ratio of scatter ray and image quality in chest X-ray radiography. The results were as follows: 1. By using the rare earth intensifying screen system at 120 Kvp, the sensitivity is increased by times and the exposure ratio is decreased 0.22 by comparison with the $CaWO_{4}$ intensifying screen system at 80 Kvp. 2. By using Al added filter of 1/8 value layer, the scatter ray is increased more than no filter, But the scatter ray is decreased more in $G_{4}/RxOG$ intensifying system than in LT-II/Rx intensifying system. 3. At 120 Kvp, the image quality value of $G_{4}/RxOG$ system is increased more than LT-II/Rx system compared with slight decreasing image quality value at 80 Kvp. Concluded that by using the added filter could decrease the radiation dose by 1/3 and obtain effective image quality with the added filter at high voltage hard exposure.

• Journal of the Korean Society of Radiology
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• v.11 no.7
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• pp.611-617
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• 2017

In this study, it was expected that long-term stability against external mechanical external force could be secured if the phosphor layer had ductility. In this study, a bendable $Gd_2O_2S:Tb$ sensitized paper was fabricated by screen printing method and the image uniformity was evaluated through RMS analysis and histogram analysis to investigate the effect of fatigue accumulation due to long-term external force and repetitive external force. As a result, the dominant pixel area is maintained constant and the relative standard deviation is less than 10% for the long-term external force. However, for the repetitive external force, the dominant pixel area is divided into three areas and the image uniformity is adversely affected. Based on these results, it is suggested that the curved surface detector can be applied by securing the mechanical stability against the existing radiation sensitized paper. However, further studies are needed to apply it to the flexible detector. As a result, flexible radiation sensitizers can be applied to various curved surfaces, and it is expected to be applicable to various fields such as nuclear medicine, medical treatment, and industrial fields in the future.