Detecting Environmental Radioactivity

Preface
Contents
1 Radioactivity: History and Phenomenology
1.1 Basic Description of the Atomic Nucleus. Nuclear Stability
1.1.1 Simple Nuclear Models
1.1.2 Atomic and Mass Numbers. Isobars, Isotopes, and Isotone Nuclei
1.1.3 Unstable Nuclides
1.2 Discovery of Radioactivity
1.2.1 Some Historic Data
1.2.2 Phenomenology of Radioactivity
1.3 Types of Radioactivity
1.3.1 Alpha Radioactivity
1.3.2 Beta Radioactivity: Electrons, Positrons, and Electron Capture
1.3.3 Gamma Radioactivity: Electromagnetic Radiation, Conversion Electrons, and Isomers
1.3.4 Other Radioactivity Types: Double Beta Decay, Proton and Neutron Emissions, Exotic Radioactivity, Fission
1.4 X-rays. Auger Electrons
References
2 Radioactivity: Decay Law, Definitions, and Units
2.1 Exponential Decay Law. Decay Constant, Half-Life and Mean-Life
2.2 Radioactive Activity and Units
2.2.1 Exponential Law of Activity
2.2.2 Becquerels and Curies
2.3 Radioactive Series
2.3.1 Bateman Equations
2.3.2 Transient and Secular Equilibria
2.4 Partial Activities. Branching Ratio and Intensity of Radiation
2.5 Decay Schemes
References
3 Natural and Artificial Radioactivity
3.1 Primordial Radionuclides
3.1.1 Long-Lived Radionuclides
3.1.2 Natural Radioactive Series
3.2 Cosmogenic Radionuclides
3.2.1 Cosmic Radiation
3.2.2 Production of Radionuclides by Cosmic Radiation
3.3 Artificial Radionuclides
3.3.1 Some Historic Data
3.3.2 Production of Radionuclides in Accelerators
3.3.3 Production of Radionuclides in Nuclear Reactors
References
4 Environmental Radioactivity
4.1 Presence of Natural Radioactivity in the Environment
4.1.1 Primordial Radionuclides
4.1.2 Cosmogenic Radionuclides
4.1.3 NORM Materials and Non-nuclear Industries
4.2 Sources of Artificial Radionuclides
4.2.1 The Start of the Nuclear Era. The Bomb Pulse
4.2.2 Radioactive Fallout
4.2.3 Nuclear Fuel Reprocessing Plants
4.2.4 Other Nuclear Facilities and Activities: Nuclear Power Plants
4.2.5 Nuclear Accidents
References
5 Levels and Behavior of Environmental Radioactivity
5.1 Dynamics of Radioactivity in the Environment
5.1.1 General Concepts of Radioecology
5.1.2 Radionuclide Speciation in the Environment
5.1.3 Exchange and Transport Processes. Transfer Parameters
5.1.4 Mathematical Modeling
5.2 Levels and Behavior of Radioactivity in the Atmosphere
5.2.1 Radioactivity in the Air
5.2.2 The Radon Problem
5.3 Levels and Behavior of Radioactivity in the Lithosphere. Radioactive Particles
5.3.1 Soils
5.3.2 Radioactive Particles
5.4 Levels and Behavior of Radioactivity in Fresh Waters
5.4.1 Rivers and Sediments
5.4.2 Lakes and Sediments
5.4.3 Groundwater
5.5 Levels and Behavior of Radioactivity in Oceans
5.5.1 Global Circulation
5.5.2 Seawater
5.5.3 Marine Sediments
5.6 Levels and Behavior of Radioactivity in the Biosphere
5.6.1 Plants, Animals
5.6.2 Seaweed and Other Marine Bioindicators
5.7 Levels and Behavior of Radioactivity in Foods
5.7.1 Drinking Water
5.7.2 Foodstuffs and Food Raw Materials
References
6 Radiological Impact. Radiation Dosimetry
6.1 Radiation Dosimetry
6.1.1 Radiation Exposure, Absorbed Dose and Dose Equivalent: Magnitudes and Units
6.1.2 Effective and Committed Doses and Other Magnitudes
6.2 Biological Effects of Radioactivity
6.2.1 Stochastic and Deterministic Effects
6.2.2 Radiation Effects on Human Health
6.3 Radiological Impact
6.3.1 Radiation Protection Programs
6.3.2 Radiation Protection Regulations
References
7 Principles of Radiation Detection: Interaction of Radiation with Matter
7.1 Interaction of Gamma Radiation with Matter
7.1.1 Photoelectric Effect
7.1.2 Compton Effect
7.1.3 Pair Production
7.1.4 Attenuation and Absorption Coefficients
7.1.5 Designing Gamma Radiation Detectors
7.2 Interaction of Charged Particles with Matter
7.2.1 Ionization and Excitation
7.2.2 Stopping Power. The Bethe-Bloch Equation
7.2.3 Bremsstrahlung
7.2.4 Cherenkov Radiation
7.2.5 Range, Specific Ionization, and Bragg Curves
7.2.6 Designing Charged-Particle Detectors
7.3 Nuclear Reactions. Interaction of Neutrons with Matter
7.3.1 Nuclear Reactions with Neutrons
7.3.2 Path of Neutrons Through Matter
7.3.3 Designing Neutron Detectors
References
8 Principles of Radiation Detection: Counting and Spectrometry
8.1 Introduction
8.2 Counting Efficiency
8.2.1 Absolute Efficiency
8.2.2 Partial Efficiencies. Photopeak Efficiency
8.3 Background of Detectors
8.3.1 Sources and Components
8.3.2 Background Corrections
8.4 Dead Time
8.4.1 Sources of Dead Time
8.4.2 Dead-Time Corrections
8.5 Energy Spectra
8.5.1 Components
8.5.2 Energy Resolution
References
9 Gas Ionization Detectors
9.1 Physics of Gas Ionization Detectors
9.1.1 Ionization in Gases
9.1.2 Charge Transfer Reactions in Gases
9.1.3 Multiplication of Charge in Gases. Townsend Avalanche
9.2 Ionization Chamber
9.3 Proportional Counters
9.4 Geiger–Müller Counters
9.5 Radiation Counting and Spectrometry with Gas Ionization Detectors
9.6 Background in Gas Ionization Detectors
References
10 Scintillation Detectors
10.1 Physics of Scintillation Detectors
10.1.1 Organic Scintillators
10.1.2 Inorganic Scintillators
10.1.3 Gas Scintillators
10.1.4 Photomultipliers
10.2 Counting and Spectrometry with Scintillation Detectors
10.3 Gamma-Ray Spectrometry with Scintillation Detectors
10.3.1 Pulse Height Spectrum
10.3.2 Identification of Radionuclides and Activity Calculation
10.4 Counting and Spectrometry with Liquid Scintillation Detectors
10.4.1 Technical Aspects
10.4.2 Applications
10.5 Background in Scintillation Detectors
References
11 Semiconductor Detectors
11.1 Physics of Semiconductor Detectors
11.1.1 Electron-hole Production
11.1.2 Energy Resolution
11.1.3 Types of Semiconductor Detectors
11.2 Gamma-Ray Spectrometry with Semiconductor Detectors
11.2.1 Pulse Height Spectrum
11.2.2 Identification of Radionuclides and Activity Calculation
11.3 Alpha- and Beta-Spectrometry with Semiconductor Detectors
11.3.1 Pulse Height Spectrum
11.3.2 Activity Determination
11.4 X-ray Spectrometry with Semiconductor Detectors
11.4.1 Pulse Height Spectrum
11.4.2 Activity Determination
11.5 Background in Semiconductor Detectors
References
12 Dosimeters, Other Detectors, and Specific Designs
12.1 Dosimeters
12.1.1 Active Dosimeters
12.1.2 Passive Dosimeters
12.2 Track Detectors
12.3 ΔE–E Telescopes
12.4 Time-Of-Flight Spectrometers
12.5 Cherenkov Detectors
12.5.1 Cherenkov Threshold Counters
12.5.2 Cherenkov Differential Detectors
12.5.3 Cherenkov Circular Image Detectors
References
13 Radiochemistry for Environmental Samples
13.1 Sampling Techniques
13.1.1 Solid Samples
13.1.2 Liquid Samples
13.1.3 Atmospheric Samples
13.1.4 Biological Samples
13.2 Sample Transport and Storage
13.3 Chemical Procedures
13.3.1 Preconcentration Processes
13.3.2 Separation and Purification Procedures
13.3.3 Source Preparation for Counting and Spectrometry
13.4 Yield Determination
13.5 Efficiency Calibration of Radiation Counters and Spectrometers
13.5.1 Calibration Curves for Charged Particles
13.5.2 Calibration Curves for Gamma Radiation
13.6 Speciation Studies
13.7 Quality Assurance
References
14 Principles of Low-Level Counting and Spectrometry
14.1 Need of Low-Level Counting Techniques (LLC)
14.1.1 Levels of Radioactivity in the Environment
14.1.2 Problems Requiring LLC
14.2 Counting Statistics
14.2.1 The Random Nature of Radioactivity
14.2.2 Uncertainty Calculations in Radioactivity Measurements
14.3 Figure of Merit (FOM)
14.3.1 Definition and FOM Equation
14.3.2 Analysis of the FOM Equation
14.4 Generalized Figure of Merit
14.4.1 Definition and Equation
14.4.2 Analysis of the Equation
14.5 Designing an LLC Experiment
14.5.1 Sampling Strategy
14.5.2 Counting or Spectrometry, or Both
14.6 Limit of Detection and Minimum Detectable Activity
References
15 Low-Level Counting and Spectrometry Techniques
15.1 Techniques for Detector Background Suppression
15.1.1 Passive Shielding
15.1.2 Active Shielding
15.1.3 Underground Laboratories
15.2 Techniques for Increasing Counting Efficiency
15.2.1 External Counting and Spectrometry
15.2.2 Internal Counting and Spectrometry
15.2.3 Radiation Coincidence Techniques
References
16 Principles of Mass Spectrometry
16.1 Limitations of Radiometric Methods. Need for Mass Spectrometry Techniques
16.1.1 Loss of Information by Counting Emitted Radiation
16.1.2 Counting Atoms Instead of Emitted Radiation
16.2 Basics of Mass Spectrometry
16.2.1 Electrostatic and Magnetic Rigidity
16.2.2 The Mass-Energy Plane
16.2.3 The Dynamic Approach
16.3 Low-Energy Mass Spectrometers: TIMS, SIMS, GDMS, RIMS, ICP‒MS
16.4 Applications to Environmental Radioactivity
References
17 Principles of Particle Accelerators
17.1 Need of Accelerators
17.2 Parts of an Accelerator
17.2.1 The Ion Source
17.2.2 The Acceleration Step
17.2.3 The Reaction Chamber
17.2.4 Ion Optics and Other Elements
17.3 Electrostatic Accelerators
17.3.1 Van de Graaff Accelerators
17.3.2 Cockcroft–Walton Accelerators
17.4 Linear Accelerators (LINACS)
17.5 Circular Accelerators
17.5.1 Cyclotrons
17.5.2 Synchrotrons
17.6 Applications of Accelerators to Environmental Problems
References
18 Accelerator Mass Spectrometry (AMS)
18.1 Experimental Challenges in the Determination of Radioactivity in the Environment
18.2 Limitations of Low-Energy Mass Spectrometry
18.2.1 Isobar and Molecular Background
18.2.2 Mass-To-Charge Ratio Background
18.3 History of AMS
18.3.1 Early Measurements. The 14C Dating Problem
18.4 Principles and Contributions of AMS
18.4.1 Typical AMS Systems
18.4.2 The Ion Source and Low-Energy Side. Advantages of Accelerating Negative Ions
18.4.3 The Tandem. Charge Stripping and Tandem Beams. Molecular Background Suppression
18.4.4 High-Energy Side and Ion Detectors. Isobar Rejection
18.4.5 Measurements in AMS
18.5 Low-Energy AMS (LEAMS)
18.5.1 The Use of Low-Terminal Voltages
18.5.2 Charge Stripping at Low-Terminal Voltages
18.5.3 Some Examples of LEAMS Systems
18.6 AMS Applications to Environmental Radioactivity
18.6.1 AMS Sample Preparation
18.6.2 AMS in Environmental Radioactivity
References
19 Neutron Activation Analysis
19.1 Principles of Neutron Activation Analysis (NAA)
19.1.1 Neutron Activation of Materials
19.1.2 Prompt Gamma NAA (PGNAA)
19.1.3 Delayed NAA (DNAA)
19.1.4 Radiochemical and Instrumental NAA
19.2 General Equation
19.2.1 The Mass Equation
19.2.2 Mass Determination Methods
19.3 Sensitivity, Interferences, and Limitations
19.3.1 Analysis of the Mass Equation. Design of an NAA Experiment
19.3.2 Types of Interferences
19.4 Experimental Systems
19.4.1 Radioisotope Sources
19.4.2 Nuclear Reactors
19.4.3 Neutron Generators. Accelerator-Based Neutron Sources
19.5 Other Neutron-Based Analytical Techniques
19.5.1 Neutron Resonance Capture Analysis
19.5.2 Neutron Resonance Transmission Analysis
19.6 Applications to Environmental Radioactivity
References
20 Radioactive Particle Characterization
20.1 Radioactive Particle Characterization
20.2 Radioactive Particle Identification and Isolation
20.2.1 Radiometric Methods
20.2.2 Imaging Techniques
20.2.3 Particle Isolation and Manipulation
20.3 Radioactive Particle Size, Morphology, and Composition
20.3.1 Electron Microscopy
20.3.2 Computed Tomography (CT)
20.3.3 Nano- and µ-XRF Techniques
20.3.4 Nuclear Microprobes
20.4 Radioactive Particle Characterization
20.4.1 X-ray Diffraction (XRD)
20.4.2 XANES and EXAFS
20.4.3 Electron Spectroscopy Techniques (EELS, STEM-HAADF)
References
Index