Titel: Optically Stimulated Luminescence Dosimetry
Autor/en: L. Boetter-Jensen, S. W. S. McKeever, A. G. Wintle
November 2003 - gebunden - 374 Seiten
Optically Stimulated Luminescence (OSL) has become the technique of choice for many areas of radiation dosimetry. The technique is finding widespread application in a variety of radiation dosimetry fields, including personal monitoring, environmental monitoring, retrospective dosimetry (including geological dating and accident dosimetry), space dosimetry, and many more. In this book we have attempted to synthesize the major advances in the field, covering both fundamental understanding and the many applications. The latter serve to demonstrate the success and popularity of OSL as a dosimetry method. The book is designed for researchers and radiation dosimetry practitioners alike. It delves into the detailed theory of the process from the point of view of stimulated relaxation phenomena, describing the energy storage and release processes phenomenologically and developing detailed mathematical descriptions to enable a quantitative understanding of the observed phenomena. The various stimulation modes (continuous wave, pulsed, or linear modulation) are introduced and compared. The properties of the most important synthetic OSL materials beginning with the dominant carbon-doped Al2O3, and moving through discussions of other, less-well studied but nevertheless important, or potentially important, materials. The OSL properties of the two most important natural OSL dosimetry material types, namely quartz and feldspars are discussed in depth. The applications chapters deal with the use of OSL in personal, environmental, medical and UV dosimetry, geological dating and retrospective dosimetry (accident dosimetry and dating). Finally the developments in instrumentation that have occurredover the past decade or more are described. The book will find use in those laboratories within academia, national institutes and the private sector where research and applications in radiation dosimetry using luminescence are being conducted. Potential readers inclu
1.1 Optically stimulated luminescence. 1.2 Historical development of OSL dosimetry. 1.3 OSL dosimetry. 1.3.1 Personal dosimetry. 1.3.2 Environmental dosimetry. 1.3.3 Medical dosimetry. 1.3.4 Retrospective dosimetry. 1.4 This book. CHAPTER
2: OPTICALLY STIMULATED LUMINESCENCE THEORY.
2.1 Stimulated luminescence. 2.2 Generalised mathematical description of optically stimulated luminescence. 2.3 The photoionisation cross-section. 2.3.1 Optical transitions. 2.3.2 Wavelength dependence. 2.3.3 Measurement of the photoionisation cross- section. 2.4 CW-OSL. 2.4.1 Models and rate equations. 2.4.2 The one-trap/one-centre model. 2.4.3 Models containing multiple-traps and centres. 2.4.4 A more generalised model. 2.4.5 Temperature dependence effects. 2.4.6 Thermal quenching. 2.5 LM-OSL. 2.5.1 First-order and general-order-kinetics. 2.5.2 Relationship between LM-OSL and CW-OSL. 2.5.3 Wavelength dependence of LM-OSL. 2.5.4 Photoconductivity. 2.6 Pulsed OSL. 2.6.1 Principles of POSL. 2.6.2 Delayed OSL (DOSL). 2.7 Phototransferred effects. 2.7.1 Procedure. 2.7.2 Mathematical description and typical data. 2.8 Radiophotoluminescence. 2.8.1 Procedure. CHAPTER
3: OSL PROPERTIES OF SYNTHETIC MATERIALS.
3.1 Al2O3. 3.1.1 Introduction. 3.1.2 Crystal growth. 3.1.3 OSL stimulation and emission characteristics of Al2O3:C. 3.1.4 The OSL response of Al2O3:C to radiation exposure. 3.1.5 The temperature dependence of OSL from Al2O3:C. 3.1.6 Zeroing of the OSL signal from Al2O3:C. 3.2 Halides. 3.2.1 KCl. 3.2.2 KBr. 3.2.3 NaCl. 3.2.4 RbI. 3.2.5 CaF2. 3.2.6 BaFX (X=Br, Cl, I). 3.3 Sulphates. 3.3.1 MgSO4. 3.3.2 CaSO4. 3.4 Sulphides. 3.4.1 AS (A = Mg, Sr, Ca, Ba). 3.5 Oxides. 3.5.1 BeO. 3.5.2 Fused quartz. CHAPTER
4: PASSIVE OPTICALLY STIMULATED LUMINESCENCE DOSIMETRY.
4.1. Personal dosimetry. 4.1.1 Introduction. 4.1.2 Landauer's LuxelTM personal dosimetry system. 4.1.3 Landauer's InLightTM personal dosimetry system. 4.1.4 Beta dosimetry. 4.1.5 POSL imaging. 4.2. Environmental OSL dosimetry using Al2O3. 4.2.1 Measurement of the natural terrestrial background radiation. 4.2.2 Measurement of the natural space background radiation. 4.3. UV dosimetry. 4.4. OSL and RL remote optical fibre dosimetry in medical applications. 4.4.1 Real-time in-vivo monitoring of doses during radiotherapy. 4.4.2 Optical fibre dosimeters. CHAPTER
5: OSL PROPERTIES OF NATURAL MATERIALS.
5.1 Quartz. 5.1.1 Crystal structure and point defects. 5.1.2 Decay curve shapes obtained under continuous stimulation - CW-OSL. 126.96.36.199 Stimulation sources. 188.8.131.52 Effect of the 110 degreeC trap. 184.108.40.206 Dependence on power. 220.127.116.11 Three components. 18.104.22.168 Effect of stimulation wavelength. 22.214.171.124 Effect of stimulation temperature. 5.1.3 Linear modulation OSL - LM-OSL. 126.96.36.199 LM-OSL at 160 degreeC with 470 nm stimulation. 188.8.131.52 LM-OSL at different temperatures with 526 nm stimulation. 5.1.4 Pulsed OSL. 184.108.40.206.1 TRL. 220.127.116.11.2 DOSL or OSA. 5.1.5 Excitation spectra. 18.104.22.168 Bleaching response spectrum. 22.214.171.124 Excitation spectra after bleaching by 514 ± 25 nm light. 126.96.36.199 Continuous scanning of stimulation wavelengths. 188.8.131.52 Excitation interference filters and using xenon lamp. 184.108.40.206 Excitation using laser lines from 458 to 645 nm. 220.127.116.11 Stimulation in the infrared 780 - 920 nm. 5.1.6 Emission spectra. 18.104.22.168 OSL emission spectra. 22.214.171.124 TL emission spectra. (i)360 - 420 nm (near UV to violet). (ii)420 - 490 nm (blue). (iii) 590 - 650 nm (orange). 126.96.36.199 Radioluminescence. 5.1.7 Dose dependence. 188.8.131.52 Fast component. (i) Multiple aliquot data. (ii) Single aliquot data. (iii) Single grain data. 184.108.40.206 Low doses. 5.1.8 Effects of previous thermal treatment. 220.127.116.11 High temperature annealing - above 500 degreeC. (i) Comparison of LM-OSL, TL, RL and EPR. (ii) CW-OSL growth curves after annealing. 18.104.22.168 Low temperature annealing - 160 to 280 degreeC. 22.214.171.124 Thermal stability. (i) Isothermal decay. (ii) Pulse annealing. 126.96.36.199 Irradiation at elevated temperature. 188.8.131.52 Thermal transfer. 5.1.9 Raised temperature OSL. 184.108.40.206 Thermal quenching. 220.127.116.11 Thermal assistance. 5.1.10 The slow component. 18.104.22.168 Thermal stability. 22.214.171.124 Growth curve. 126.96.36.199 Optical bleaching. 5.1.11 Photoionisation cross-section. 5.1.12 Modelling processes that give rise to OSL in quartz. 5.1.3 Summary. 5.2 Feldspars. 5.2.1 Crystal structure. 5.2.2 Decay curve shape obtained under continuous stimulation - CW-OSL and CW-IRSL. 188.8.131.52 Stimulation sources. 184.108.40.206 Effect of stimulation temperature. (i) initial signal. (ii) decay curve shape. 5.2.3 Linear modulation IRSL (LM-OSL). 5.2.4 Pulsed OSL and IRSL. 220.127.116.11 Pulsed OSL. 18.104.22.168 Pulsed IRSL. 22.214.171.124 Optically stimulated afterglow. 5.2.5 Excitation spectra. 126.96.36.199 Direct measurements. 188.8.131.52 Bleaching response spectrum. 5.26 Emission spectra. 184.108.40.206 IRSL emission spectra. (i) 280-290 nm (near--UV). (ii) 320-340 nm (near--UV). (iii) 390-440 nm (violet/blue). (iv) 550-570 nm (yellow/green). (v) 600-750 nm (red/far red). 220.127.116.11 TL emission spectra. 18.104.22.168 RL emission spectra. (i) under X-ray stimulation at low temperature. (ii) under X-ray stimulation above room temperature. (iii) under beta stimulation from a 137Cs source. 22.214.171.124 PL emission spectra. 5.2.7 Effects of previous optical treatment. 126.96.36.199 Bleaching at ambient temperature. 188.8.131.52 IR bleaching at elevated temperature. 5.2.8 Effects of previous thermal treatment. 184.108.40.206 Preheating of laboratory and naturally irradiated samples. 220.127.116.11 Pulse annealing. 18.104.22.168 Irradiation at elevated temperature. 5.2.9 Raised temperature IRSL and OSL. 22.214.171.124 Thermal quenching. 126.96.36.199 Thermal assistance. (i) above room temperature. (ii) below room temperature. (iii) wavelength dependence. (iv) link to anomalous fading. 5.2.10 Anomalous fading. 188.8.131.52 TL, OSL and IRSL. 184.108.40.206 Attempts to remove anomalous fading. (i) using a preheat. (ii) using an optical treatment. 220.127.116.11 Attempts to avoid anomalous fading. (i)using time--resolved measurements. (ii)using different detection wavelengths. 18.104.22.168 CL and TL spectra of fading feldspars. 22.214.171.124 Low temperature phosphorescence. 126.96.36.199 Single grain IRSL fading and fadia plots. 188.8.131.52 Logarithmic signal decay. 184.108.40.206 Correcting for anomalous fading. 5.2.11 Radioluminescence. 220.127.116.11 A new dating method. 18.104.22.168 Practical considerations. 22.214.171.124 Methods of De determination. 126.96.36.199 Thermal stability. 188.8.131.52 Single grain measurements. 5.2.12 Models for IRSL, OSL, IR-RL in feldspars. 184.108.40.206 IRSL. 220.127.116.11 OSL. 18.104.22.168 IR-RL. 22.214.171.124 Comparison of IR-RL and IRSL (or OSL). 5.3 Conclusions. CHAPTER
6: RETROSPECTIVE OSL DOSIMETRY. Part I: RETROSPECTIVE ACCIDENT DOSIMETRY.
6.1. Introduction. 6.2. Materials and sampling. 6.3. Sample preparation and experimental details. 6.4. Determination of the accident dose. 6.4.1 Retrospective assessment of environmental dose rates. 6.4.2 Estimation of the accident dose. 6.5. Analytical protocols. 6.5.1 Introduction. 6.5.2 Multiple-aliquot protocols. 6.5.3 The Single Aliquot Regeneration and Added Dose (SARA)protocol. 6.5.4 True single-aliquot protocols. 126.96.36.199 Introduction. 188.8.131.52 Variation of OSL signal with preheat. 184.108.40.206 Choice of OSL signal. 220.127.116.11 Sensitivity changes with regeneration cycles. 18.104.22.168 The single-aliquot regeneration (SAR) protocol. 6.6. Evaluation of dose-depth profiles in bricks. 6.6.1 Continuous OSL scanning. 6.6.2 Determination of depth-dose profiles from Chernobyl bricks. 6.6.3 Absolute errors and estimated precision of the equivalent dose in bricks. 6.7. Retrospective OSL dosimetry using unheated quartz. 6.7.1 Dose distributions. 6.7.2 Thermal transfer and sensitivity changes. 6.7.3 Concrete. 6.8 Retrospective OSL dosimetry using household and workplace chemicals. 6.9 Retrospective OSL dosimetry using porcelain. 6.9.1 Introduction. 6.9.2 The origin of OSL in porcelain. 22.214.171.124 Time-decaying dose-dependent OSL signals. 126.96.36.199 Time-steady PL emission spectra from porcelain. 188.8.131.52 OSL stimulation spectra. 6.9.3 OSL dose response of porcelain. 6.9.4 Dose-depth profiles in porcelain and the effect of transparency. 6.9.5 OSL dosimetry using porcelain dental crowns. 6.10 Retrospective accident dosimetry - conclusions. Part II: GEOLOGICAL AND ARCHAEOLOGICAL DATING. 6.11 Measurement Procedures. 6.11.1 Multiple-aliquot methods. 6.11.2 Single-aliquot methods. 184.108.40.206 Feldspars. (i) Additive dose. (ii) Regenerative dose. 220.127.116.11 Quartz. (i) Additive dose. (ii) Regenerative dose. 18.104.22.168 Luminescence sensitivity. (i) Multiple luminescence signals. (ii)Comparison of the 110 degreeC TL peak and OSL. 22.214.171.124 Reliability of OSL monitoring of sensitivity change. 6.11.3 Dose distributions for single aliquots. 126.96.36.199 Histograms. 188.8.131.52 Probability plots. 184.108.40.206 Radial plots. 220.127.116.11 Calculation of De. 6.12 Single grains. 6.12.1 Measurements. 18.104.22.168. Feldspars. 22.214.171.124 Quartz. 6.12.2 Dose distributions for single grains. 126.96.36.199 Histograms. 188.8.131.52 Probability plots. 184.108.40.206 Radial plots. 220.127.116.11 Calculation of De. 6.13 Geological and archaeological dating-conclusions. CHAPTER
7: OSL MEASUREMENT TECHNOLOGY.
7.1 Stimulation modes. 7.1.1 CW-OSL. 7.1.2 LM-OSL. 7.1.3 POSL. 7.2 The light detection system. 7.2.1 Photomultiplier tubes. 7.2.2 Imaging photon detectors. 7.2.3 Solid state detectors. 7.3 Automated OSL readers. 7.4 Development of optical stimulation sources. 7.4.1 Laser stimulation. 7.4.2 IR LED stimulation. 7.4.3 IR laser diode stimulation. 7.4.4 Broad-band light stimulation. 7.4.5 Optimisation of OSL detection. 7.4.6 Green LED stimulation. 7.4.7 Blue LED stimulation. 7.4.8 Blue LED and cut-off filter characteristics. 7.4.9 Ramping the LEDs. 7.4.10 Pulsed and time-resolved OSL. 7.5 Wavelength resolved OSL. 7.5.1 Stimulation spectrometry. 7.5.2 Emission spectrometry. 7.6 Imaging systems. 7.7 Single grain OSL systems. 7.7.1 Introduction. 7.7.2 CCD luminescence imaging systems. 7.7.3 Single grain laser OSL systems. 7.8 Automatic OSL scanners. 7.9 Portable systems for OSL measurements in the field. 7.10 The measurement of radioluminescence. 7.11 Commercially available OSL apparatus. 7.12 Future developments.