Study and Development of Some Materials Used as a Radiation Dosimeter

Abstract

In radiological emergencies, table salt can be considered an established method for the retrospective dosimetry of previous exposures and the dosimetry of probably exposed people, where it is a material that can be expected to be easily available in accident locations and it can easily be sampled collection. This thesis deals with the study of the properties of thermoluminescence to four types of salt different source of sodium chloride which is characterized by its availability in abundance in nature and cheap price in order to be used in radiation dosimetry and in particular retrospective dosimetry. This thesis contains four chapters as follows: Chapter I This chapter includes an introduction about the radiation, dosimetry, dose limits of radiation and retrospective dosimetry. Also includes published research on the study and analysis of sodium chloride salt. Chapter II This chapter exposed to discuss the theoretical basis of thermoluminescence phenomena and a detailed explanation of this phenomenon, as well as to be met by the properties of thermoluminescence materials. Chapter III This chapter is exposed to explain the four types of NaCl different source and processing of irradiation and measurement, also includes a description of the devices used in this investigation, such as thermoluminescence reader, the cell used in the irradiation processes. Chapter IV This chapter deals with the obtained experimental results, and these results are summarized as follows: This thesis is a study of some dosimetric properties for four different commercial salt samples of sodium chloride (NaCl), obtained from different sources. Indian salt (supplied by oxford lab), Egyptian table salt (SAL), Saudi Arabian table salt (MASA) and British table salt (Cook’s), are the four nominated types of salt to procedure in this work. Samples were irradiated with Gamma source using Cs-137. TL analysis of the samples were done using Harshaw Model 4500 TLD Reader, with WinREMS (Windows Radiation Evaluation and Management System) at heating rate 5 oC /sec with final temperature set to 350 oC. One prominent glow peak is observed in the glow curve at around 216 - 222 oC for the nominated salt samples. The results show that, TL intensity of the glow curve is direct proportional to the grain size. The results indicate that, Cook’s salt is the most sensitive and preferable one to complete the study. The results show also that, TL intensity of the chosen salt has a linear response with the dose for a broad range from 250 mGy to 20 Gy. The post-irradiated fading rates are investigated and show stability after 8 days. The fading at room temperature was monitoring during 24 days. Cook’s salt may be candidate for using as a Gamma ray retrospective dosimeter.