X-Ray Phosphors and Scintillators (Counting Techniques)

Abstract

In Chapter 8, the excitation was exclusively by X-ray irradiation. In this chapter the stress will be on other types of ionising radiation such as 'Y rays and charged particles. In many cases, their energy will be higher than that of X rays. In all applications the counting of the number of ionizing events is essential. This method of radiation detection gives information on quantities such as the kind of radiation, the intensity, the energy, the time of emission, the direction and the position of the emission. Many of the applications use luminescent materials in the form of large single crystals.The organisation of this chapter is as follows. In Sect. 9.2 the principles of the interaction between ionizing radiation and condensed matter will be dealt with. In Sect. 9.3 the principles of several applications will be discussed and the material requirements specified. The preparation of the materials will concentrate on single crystal growth and will be discussed in Sect.9.4. Finally Sect. 9.5 will give a survey of the several materials in use and Sect. 9.6 will present a future outlook. For more details than presented here, the reader is referred to the proceedings of a recent workshop [I]. The Interaction of Ionizing Radiation with Condensed MatterThere are three ways in which ionizing (electromagnetic) radiation interacts with matter, viz.-the photoelectric effect -the Compton effect -pair production.

A Study on Mechanical Characteristics of Phosphor Film Containing Methyl Silicone Resin Based on Crosslinking Reaction Analysis

“…While curing, the double bond of the vinyl group in the base resin was broken due to the Pt(-complex) catalyst and it formed bonds with the Si–H of the cross-linker, resulting in crosslinking. The curing procedure of such methyl silicone resin made it possible to observe and measure the curing reaction heat generated by the exothermic reaction [ 1 , 27 ]. The properties of the three types of methyl silicone are as shown in Table 1 The mixing viscosity was measured at the fixed spindle shear rate (2.5 s −1 ) under a thermostatic bath (23 °C) connected with a rotational viscometer (DV-I prime, Brookfield, WI, USA) based on the KS M ISO 3219 standard.…”

“…Silicate phosphors have a narrow luminescence spectrum compared to oxide phosphors, so their color rendering property is lower. However, silicate phosphors have excellent chromaticity according to the operating current, and thus has the advantage that various wavelengths ranging from green and yellow to orange can be carried out by changing the chemical composition [ 1 , 2 , 3 , 4 , 5 ]. Phosphors are generally used in the form of a film, i.e., a phosphor film, combined with transparent materials such as PMMA (poly methyl methacrylate), epoxy resins, and glass.…”

Characteristics of the Maximum Glow Intensity According to the Thermoluminescent Phosphors used in the Absorbed Dose Measurement of the Radiation Therapy

“…또한 CaF 선량계는 LiF 선량계와 비교하여 형광 감도는 우수하지만 에너지 의존성이 크다는 단 점이 있다 [10], [11] . 이를 개선하기 위하여 LiF 선량계는 파우더 형태의 LiF:Mg·Ti(TLD-100: 99.96% 7Li, 0.04% 6Li)을 사용하여 결정의 크기 및 균일도 의존성을 개 선하고 열형광 판독 및 교정 유효성을 증가시켜 치료 방사선 선량보증 사업에 이용되고 있으며 [12]- [14] CaF 선량계의 경우 방사선량에 민감한 활성제(CaF2:Cu, CaF2:Tm, CaF2:Dy, CaF2:Mn) 첨가에 따른 형광 스펙트 럼을 변화시키고 가열온도에 대한 열형광 응답(TL response) 속도를 감소시켜 효율성을 증대하려는 노력 이 있었다 [15], [16] . [17], [18] .…”