Doğal Bor Mineralleri Kullanarak Radyasyon Dozimetresi Geliştirilmesi

Abstract

In this thesis study; it is aimed to develope a radiation dosimeter by using natural boron minerals in order to determine the radiation dose absorbed by people living and/or working in different sectors where ionizing radiation is present. In this study, natural boron minerals Colemanite-1, Colemanite-2, Inyoite and Ulexite obtained from different regions of Bigadiç in Balıkesir were used. The structural analysis of the minerals obtained as rocks was carried out by X-Ray Diffraction Method (XRD) and Scanning Electron Microscope (SEM) and Energy Dispersive X-Ray Spectroscopy (EDX) analysis. According to XRD results, natural boron mineral Colemanite-1 and Colemanite-2 are in monoclinic structure, and their crystallite dimensions are 39.45 nm and 39.36 nm, respectively. The natural boron mineral ulexite has a triclinic structure and its crystallite size is 41.26 nm. The natural boron mineral Inyoite has a monoclinic structure and its crystallite size is 39.37 nm. SEM analysis for structural morphology and EDX for elemental analysis were performed. As a result of the elemental analysis, B,O,Sr,Ca elements were determined in the structure of the natural boron mineral Colemanite sample, C,O,Na,Ca elements in the structure of the natural boron mineral Ulexite sample, and O,Ca elements in the structure of the natural boron mineral Inyoite sample. The natural Boron minerals studied during the thesis are cGy (1, 2, 3, 4, 5, 6, 7, 8, 9, 10 cGy), Gy (6.9) and kGy (1, 2, 3, 4, 5, 6, 7, 8 kGy) with different irradiation sources. In addition to these irradiation studies, UV irradiation studies were also carried out. The examination of the radiation dosimeter material, which is aimed to be developed, was dominantly carried out by Electron Spin Resonance (ESR) spectroscopy. In order to determine the optimum experimental conditions for ESR, microwave power and modulation amplitude studies were carried out and the optimum microwave power was determined as 1 mW and the optimum modulation amplitude as 1 G. The spectroscopic splitting factor g-value, which is an important spectral parameter in ESR spectroscopy; natural boron mineral was determined as 2.0021 and 2.0011 for the sample Colemanite-1 and Colemanite-2, respectively. The g-value is 2.0016 for the natural boron mineral Ulexite and 2,0009 for Inyoite. Peak-to-peak line width ∆Hpp value is found to be 4.56 G for Colemanite-1, 7.10 G for Colemanite-2, 6.55 G for Ulexite, and 6.32 G for Inyoite. It was observed that the dose dependence of the natural Boron minerals examined within the scope of the thesis was very low for cGy and Gy level irradiations, while there was an increase in ESR signal intensity values for all samples for irradiations carried out kGy range. Among the samples examined, among the samples examined, the highest dose-response curves were determined for Colemanite-1 and Colemanite-2.However, when the ESR results of the irradiated samples are detailed, it is concluded that some radiation sensitive and stable resonance peaks of the irradiated samples can also be used for dosimetric purposes. In this context, when the dose-response curves and time studies data obtained from irradiated natural Boron minerals; it was concluded that the 2nd and 4th resonance peaks for Colemanite-1 and Colemanite-2 samples, respectively, can be used in dose measurements because they are sensitive to radiation and more stable (time-dependent damping reduction 40% in Colemanite-1, 20% in Colemanite-2). For Ulexite and Inyoite, it was concluded that the sum of the 7th and 8th resonance peaks (middle peak) had a high dosimetric feature, respectively. There was no significant difference in the peak intensities in the spectrum of Colemanite-1 and Colemanite-2, irradiated and unirradiated with the effect of UV irradiation, there was an increase in the peak intensities of manganese in the spectrum of Ulexite and Inyoite. Within the scope of the thesis; Thermoluminescence (TL) studies were also carried out for the samples irradiated at cGy, Gy and kGy levels in order to get complementary information to the ESR data obtained to determine the dosimetric properties of the examined samples.The TL studies carried out showed that there was no significant difference between irradiated and non-irradiated natural Boron minerals.