Advanced X-ray Detector Technologies: Design and Applications

Preface
Contents
Contributors
Toward Perovskite-Related Scintillators with Necessary Stokes Shift and Thickness for Hard X-Ray Radiography and Gamma Spectroscopy
1 Attractiveness of Pb-Halide Perovskites for Scintillation Detectors of Ionizing Radiation
2 Temperature Dependence of Photoluminescence and Radioluminescence from Single-Crystal Pb-Halide Perovskites
3 Thermal Quenching Avoided in Nanocrystalline Pb-Halide Perovskites: Success of LEDs
4 What Is Hindering Transfer of LED Success to Scintillation Success Using 3D Pb-Halide Perovskites?
5 Absorption and Photoluminescence in Single-Crystal CsPbBr3
6 Absorption and Photoluminescence in Single-Crystal MAPbBr3
7 Absorption and Photoluminescence in Nanocrystals of Three-Dimensional CsPbBr3
8 X-Ray Attenuation Length Compared to Luminescence Attenuation Length
9 Optical Absorption Coefficient of Pb-Halide Perovskites in the Range of Exciton Luminescence
10 Urbach Edge Broadening
11 Temperature-Dependent Urbach Broadening as a Contributor to the Experimentally Observed Thermal Quenching of Excitonic Radioluminescence in Single-Crystal 3D Pb-Halide Perovskites
12 The Stokes Shift Challenge
13 Strategy #1: Self-Trapped Excitons in Lower-Dimensional Perovskite-Related Materials
14 Ion-Size Control of STE Relaxation: Parallels Between Alkali Halides and Halide Perovskites
15 Sacrifice of Stopping Power to Get Stokes Shift?
16 Strategy #2: Wavelength Shifter in the Perovskite Emitter or Its Supporting Matrix
17 Strategy #3: Ion Activator in Perovskite Host
References
Emerging Lead-Halide Perovskite Semiconductor for Solid-State Detectors
1 Introduction
2 Material Structure
3 Crystal Growth and Characterizations
3.1 Solution-Based Single-Crystal Growth
3.2 Commonly Used Hybrid Perovskite Single-Crystal Growth Techniques
3.3 Single-Crystal Characterization
4 Electronic Properties
4.1 Charge Transport Properties
4.2 Defects
4.3 Surface and Interface Effects
5 Solid-State Detector
5.1 Introduction
5.2 X-Ray Detectors
5.3 γ-Ray Detectors
5.4 Scintillators
6 Challenges and Future Directions
References
Modelling Spectroscopic Performance of Pixelated Semiconductor Detectors Through Monte-Carlo Simulation
1 Introduction
2 Monte-Carlo Detector Model
2.1 Photon Generation and Attenuation
2.1.1 Photon Attenuation
2.1.2 Scattering
2.1.3 Absorption
2.1.4 Fluorescence
2.2 Charge Transport
2.2.1 Charge Cloud Size
2.2.2 Signal Induction
2.2.3 Readout at the Pixelated Anode
2.3 Spectral Response Reconstruction
3 Experimental Measurements with a CdTe Detector
3.1 The CdTe Detector
3.2 Data Collection
3.3 Event Type Spectra and Charge Sharing
4 Comparison Between Model and Experiment
4.1 Simulated Detector Response
4.2 Charge Sharing Rates
4.3 Fluorescence Charge Sharing
5 Summary
References
High-Z Pixel Sensors for Synchrotron Applications
1 Towards the 4th Generation of Synchrotrons
2 Hybrid Pixel Detectors
2.1 Working Principle
2.2 Photon Counting
2.3 Charge Integrating
3 High-Z Sensor Materials
3.1 Chromium Compensated Gallium Arsenide (GaAs:Cr)
3.2 Cadmium Telluride (CdTe)
3.3 Cadmium Zinc Telluride (CdZnTe)
3.4 Other Materials
4 Outlook
References
CdTe Sensors for Space-Based X-ray Detectors
1 Introduction
1.1 Cadmium Telluride
1.1.1 Material Characteristics
1.1.2 Carrier Lifetime, Schottky Electrodes
1.1.3 Bias Polarization
1.2 Cadmium Zinc Telluride
1.3 Heritage of CdTe and CZT in Space Experiments
1.3.1 Integral
1.3.2 Swift
1.3.3 Chandrayaan-1
1.3.4 NuSTAR
1.3.5 AstroSat
1.3.6 Hitomi
1.3.7 ASIM
1.3.8 Spektr-RG
2 CdTe in STIX, Space Design Considerations
2.1 Sensor Selection
2.2 Thermal Constraints
2.3 Reliability and Redundancy
3 Displacement Damage by Energetic Protons
3.1 Ionizing Energy Loss
3.2 Displacement Damage
3.3 Equivalent Fluence Calculation
3.4 Literature
3.5 Proton Irradiation Study with STIX Sensors
3.5.1 FWHM at 31 keV
3.5.2 Electron Drift Length
3.5.3 Hole Drift Length
3.5.4 FWHM at 81 keV
3.5.5 Leakage Current
3.5.6 Polarization Time Scale
3.6 Conclusions on Radiation Hardness of CdTe
4 Summary
References
X-Ray Detectors in Medical Imaging
1 Introduction
2 Radiography
3 Fluoroscopy
4 Tomographic Imaging
5 Spectral Imaging
6 Imaging at the Higher Energy of X-Ray Photons
7 Scattered Radiation
8 Forced Fluorescence
9 Phase-Contrast Imaging
10 Summary
Bibliography
Status of DEXA Instrumentation Using Direct and Indirect Detectors
1 Introduction
2 Basic Principles and Techniques for DEXA Instrumentation
3 Different Features of Commercial Systems
3.1 Generating Low- and High-Energy Beams: Voltage Switching Versus K-Edge Filtering
3.2 Acquiring DEXA Images: Pencil Beams, Fan Beams, and Cone Beams
3.3 Photon Detectors: Direct Versus Indirect Mechanisms
4 LYSO-GAPD and GAGG-GAPD Detector for DEXA Potential Application
4.1 GAPD Photosensor
4.2 Scintillation Crystals
4.3 Approaches Used at Chonnam National University
4.3.1 DEXA Detector Configurations
4.3.2 Experimental Setup
4.3.3 Characterization of the Intrinsic Performance of the DEXA Detectors
4.3.4 Imaging Performance and Long-Term Stability
5 Summary
References
Medical Photon-Counting CT – Status and Clinical ApplicationReview
1 Introduction
2 Principles of Medical Photon-Counting CT
2.1 Properties of Solid-State Scintillation Detectors
2.2 Properties of Photon-Counting Detectors
2.3 Challenges for Photon-Counting Detectors in Medical CT
3 Preclinical Evaluation of Photon-Counting CT
References
Linearly Polarized X-ray Fluorescence Computed Tomography with a Photon Counting Detector
1 Introduction
2 Linearly Polarized X-ray Generation and Compton Scattering Suppression Theory
2.1 Linearly Polarized X-ray Generation
2.2 Compton Scattering Suppression
3 Monte Carlo Simulation
3.1 Imaging Geometry, Light Source, Detector, and Phantom
3.2 Image Reconstruction
4 Results and Discussions
5 Possibility Toward In Vivo Imaging
5.1 Imaging Time
5.2 Pulse Pile-Up Effect
5.3 Radiation Dose
6 Future of This Imaging Modality
References
3D XRF and Compton Imaging with CdTe and CdZnTe Arrays
1 3D X-Ray Fluorescence Tomography with a CdTe Array
2 Multi-isotropic Compton Imaging with CdZnTe Crystals
References
Coded Aperture Technique with CdTe Pixelated Detectors for the Identification of the 3D Coordinates of Radioactive Hot-Spots
1 Introduction
1.1 Basic Principles of Coded Aperture Imaging
1.2 Figures of Merit in Coded Aperture Imaging
1.3 The Parallax Phenomenon
2 Materials and Methods
2.1 Simulation
3 Results and Discussion
3.1 The 3D Source Localization Accuracy (3D SLA)
3.2 Spatial Resolution of a Two γ-Cameras System for Extended Sources
3.3 The Intrinsic Noise
3.4 The Optimum Geometry
3.5 The Kernel Filtering
4 Summary
References
Positron Emission Tomography (PET) Imaging Based on Sub-millimeter Pixelated CdZnTe Detectors
1 Positron Emission Tomography
2 Pixelated CdZnTe Detectors in PET
3 CdZnTe PET Detector Characterizations
3.1 Charge Sharing
3.2 Spatial Resolution
3.3 Depth of Interaction
3.4 Timing Resolution
4 Evaluation of CdZnTe PET Imaging Resolution
5 Summary
References
Index