Türkiye kaynaklı doğal kuvarsın lüminesans özellikleri ve geriye dönük dozimetri çalışmalarında kullanımı

Abstract

In luminescence dating or retrospective dosimetry, the absorbed dose in relevant material due to its age or radiation accident can only be assessed comparing the lüminesans intensities after exposing them to photons with known energy. In this type of studies, the installation of high-energy photon sources is not suitable due to radiation safety in working environment. It is often a weak beta source (90Sr/90Yr) (0.37-1.48GBq) is installed in the laboratory or built-in the luminescence equipment. The absorbed dose in the material exposed to such sources can not be assessed because the energy of betas and scattered photons can not be measured directly. Therefore, for a given material the calibration of beta sources is performed by comparing the luminescence intensities after exposing them to photons with known energy. Quartz is one of the most common mineral used in dating and retrospective dosimetry. Therefore, the dosimetric suitability of quartz obtained from Sivrihisar for beta source calibration is investigated. After the measurements of natural radionuclide concentration and crystal structure, the dosimetric properties of quartz using luminescence are investigated in detail. Rather stable dosimetric properties are obtained after application of various heat treatment and irradiation procedure. The quartz samples were irradiated with photons in Secondary Standart Dosimetry Laboratory in Munich (Helmholtz Zentrum). As a result of this study, a material has prepared to be used for beta source calibration in luminescence laboratories in Turkey and measurement protocols were designed to optimize the beta source calibration procedures.