Optically Stimulated Luminescence

Optically stimulated luminescence has developed into one of the leading optical techniques for the measurement and detection of ionizing radiation. This text covers, in a readable manner, advanced modern applications of the technique, how it can play a useful role in different areas of dosimetry and how to approach the challenges presented when working with optically stimulated luminescence.

The six chapters are as follows:

• Introduction, including a short history of OSL and details of successful applications

• Theory and Practical Aspects

• Personal Dosimetry

• Space Dosimetry

• Medical Dosimetry

• Other Applications and Concepts, including retrospective and accident dosimetry, environmental monitoring and UV dosimetry

Throughout the book, the underlying theory is discussed on an as-needed basis for a complete understanding of the phenomena, but with an emphasis of the practical applications of the technique. The authors also give background information and relevant key references on each method, inviting the reader to explore deeper into the subject independently.

Postgraduates, researchers, and those involved with radiation dosimetry will find this book particularly useful. The material is both relevant and accessible for both specialists and those new to the field, therefore is fundamental to any academic interested in modern advances of the subject.

Auteur

Stephen W. S. McKeever is Vice President for Research and
Technology Transfer at Oklahoma State University (USA). He is also
a Regents Professor in the department of physics. He was
named a Noble Research Fellow in Optical Materials in 1987.
Professor McKeever was also named the MOST (More Oklahoma Science
and Technology) Chair of Experimental Physics in 1999. He is widely
known for his research in optically stimulated luminescence (OSL)
and thermoluminescence (TL) with specific applications to radiation
dosimetry. Major accomplishments in recent years include leading a
research team that the developed optically stimulated luminescence
as a means of personal radiation dosimetry. The patented technology
was used commercially to develop a radiation dosimeter system
currently used worldwide. His special interests are space radiation
dosimetry to monitor radiation doses to astronauts on long-duration
space flights, such as a manned mission to Mars. He has authored or
co-authored over 180 scientific publications and five books.

Eduardo G. Yukihara is an Assistant Professor at Oklahoma
State University. He has been involved with research on OSL since
2000, and his research group currently focuses on the development
of the OSL technique in various fields such as space dosimetry,
medical dosimetry, accident dosimetry, neutron dosimetry, as well
as investigations in basic properties of OSL materials. He has
presented material relating to this book to students in short
courses, colloquia, a conference summer school, and invited
conference presentations. In addition, he has been invited to write
a review paper on applications of OSL in medicine and biology to
the journal Physics in Medicine and Biology.

Contenu

Preface xi

Acknowledgments xiii

Disclaimer xiv

List of Acronyms xv

1 Introduction 1

1.1 A Short History of Optically Stimulated Luminescence 1

1.2 Brief Description of Successful Applications 7

1.2.1 Personal 7

1.2.2 Space 8

1.2.3 Medical 9

1.2.4 Security 10

1.3 The Future 10

2 Theory and Practical Aspects 13

2.1 Introduction 13

2.2 Basic Aspects of the OSL Phenomenon 17

2.2.1 Energy Levels in Perfect Crystals 17

2.2.2 Defects in the Crystal 18

2.2.3 Excitation of the Crystal by Ionizing Radiation 19

2.2.4 Trapping and Recombination at Defect Levels 22

2.2.5 Thermal Stimulation of Trapped Charges 24

2.2.6 Optical Stimulation of Trapped Charges 25

2.2.7 The Luminescence Process 27

2.2.8 Rate Equations for OSL and TL Processes 33

2.2.9 Temperature Dependence of the OSL Signal 40

2.2.10 Other OSL Models 44

2.3 OSL Readout 47

2.3.1 Basic Elements of an OSL Reader 47

2.3.2 Stimulation Modalities 48

2.4 Instrumentation 58

2.4.1 Light Sources 59

2.4.2 Light Detectors 63

2.4.3 Optical Filters 67

2.4.4 Light Collection 69

2.4.5 Sample Heaters 69

2.5 Available OSL Readers 70

2.5.1 Experimental Arrangements 70

2.5.2 Automated Research Readers 71

2.5.3 Commercial Dosimetry Readers 73

2.5.4 Optical Fiber Systems 74

2.5.5 Imaging Systems 75

2.5.6 Portable OSL Readers 76

2.6 Complementary Techniques 76

2.6.1 OSL Emission and Stimulation Spectrum 76

2.6.2 Lifetime and Time-Resolved OSL Measurements 78

2.6.3 Correlations Between OSL and TL 78

2.6.4 Other Phenomena 82

2.7 Overview of OSL Materials 82

2.7.1 Artificial Materials 85

2.7.2 Natural Materials 95

2.7.3 Electronic Components 98

2.7.4 Other OSL Materials and Material Needs 98

3 Personal Dosimetry 101

3.1 Introduction 101

3.2 Quantities of Interest 102

3.2.1 Absorbed Dose and Other Physical Quantities 103

3.2.2 Protection Quantities 108

3.2.3 Operational Quantities 110

3.3 Dosimetry Considerations 111

3.3.1 Definitions 111

3.3.2 Dose Calculation Algorithm 114

3.3.3 Reference Calibration Fields for Personal and Area Dosimeters 118

3.3.4 Uncertainty Analysis and Expression of Uncertainty 119

3.4 Detectors 123

3.4.1 General Characteristics 123

3.4.2 Al 2 O 3 :C Detectors 129

3.4.3 BeO Detectors 140

3.5 Dosimetry Systems 143

3.5.1 Luxel+ Dosimetry System 143

3.5.2 InLight Dosimetry System 146

3.6 Neutron-Sensitive OSL Detectors 150

3.6.1 Development of Neutron-Sensitive OSL Detectors 151

3.6.2 Properties of OSLN Detectors 154

3.6.3 Ionization Density Effects 157

4 Space Dosimetry 163

4.1 Introduction 163

4.2 Space Radiation Environment 165

4.2.1 Galactic Cosmic Rays (GCR) 165

4.2.2 Earth's Radiation Belts (ERB) 167

4.2.3 Solar Particle Events (SPEs) 171

4.2.4 Secondary Radiation 173

4.3 Quantities of Interest 174

4.3.1 Absorbed dose, d 174

4.3.2 Dose Equivalent, H 175

4.3.3 Equivalent Dose, H T 175

4.3.4 Effective Dose, E 176

4.3.5 Gray-Equivalent, G T 176

4.4 Health Risk 177

4.5 Evaluation of Dose in Space Radiation Fields Using OSLDs (and TLDs) 178

4.5.1 The Calibration Problem for Space Radiation Fields 178

4.5.2 Thermoluminescence, TL 182

4.5.3 Optically Stimulated Luminescence, OSL 188

4.5.4 OSL Response in Mixed Fields 197

4.6 Applications 206 4.6...