Dosimetric characterization of materials with applications on archaeometry and retrospective dosimetry

Abstract

The purpose of this work is to investigate the influence of thermal quenching in quartz luminescence for the application of quartz in dating of archaeological and geological samples.Additionally, it supports to bring precise results when quartz is used for accidental and retrospective dosimetric applications. The information delivered in the present work corresponds to the theoretical study of thermal quenching as well as experimental study on the natural and artificial quartz samples via heating rates within the range 0.25 to 20K/s. The experimental is concentrated on determination of prevalent pair of thermal quenching parameters. It was followed to by the attempt of reconstruction of thermally quenched glow curve. This dissertation is organized in the following manner.Chapter 1 entitled basic introduction of interaction of matter with radiation especially with photon, neutron and charged particles.Chapter 2 entitled basic concepts of TL model, discussion of glow curve, expressions and tools used in the context of thermally stimulated luminescence (TL). This chapter can be read independently. The chapter is opened with a discussion of shapes of TL associated with a trap center and a recombination center. It includes an analysis developed to determine the trapped charge carrier distribution using TL techniques. Some of its basic terminologies of TL are attached in the title appendix after references.The theoretical aspect of thermal quenching which exist in all TL dosimeter is well explained with the help of different models of thermal quenching. The mechanism of thermal quenching described in different models in the existing literature is summarized. The thermal quenching in quartz is also discussed in brief.Chapter 3 gives detail information about quartzes and their luminescence properties. This chapter can be read independently to have a general view of luminescence of quartz. The luminescence properties in quartz are attributed by creation of defects due to irradiation. In this context various defects presents in quartzes are presented on the basis of available literature on quartz. The various fields where luminescence properties of quartzes are applicable are highlighted. The application of quartz in various sectors archeology (dating and authenticity testing), geology, accidental dosimetry and retrospective dosimetry are briefly discussed.Chapter 4 deals for experimental equipment, its operation mode, various units of Risø systems; irradiation chamber (source unit 90 Sr), heating system, light detection system and function of all 6.3. Methods of analysis ………………………………………………………….. 117 6.4. Results of heating rate measurements ………………………………………….. 120 6.4.1 Analysis of peaks within the temperature region 350-500K …………. 120 6.4.2 Determination of different sets of thermal quenching parameters …….. 123 6.4.3 Analysis of high temperature peaks (>500K) from natural TL signal …. 129 6.4.4 Fitting to evaluate thermal quenching parameters ……………………... 133 6.4.5 Evaluation of error analysis of C, W …………………………………... 137...