Neutron Detectors for Scattering Applications (Particle Acceleration and Detection)

✍ Scribed by Yacouba Diawara (editor)

• Publisher: Springer
• Year: 2023
• Tongue: English
• Leaves: 257
• Category: Library

✦ Synopsis

This book covers the most common neutron detectors used in neutron scattering facilities and all of those in use at Oak Ridge National Lab. It starts describing the facilities, instruments and the critical detector parameters needed by various instruments. Then the key components of the 3He-based linear position-sensitive detectors as well as on their electronics, which require particular attention to signal processing and noise reduction, are introduced. One chapter is dedicated to the 3He alternatives where scintillators play a critical role. It also covers emerging neutron detection technologies including semiconductors, vacuum-based devices and their associated readouts, which will be required in the future for high rate and high-resolution neutron detectors.

The authors explain the logic behind the choice of materials as well as the various constraints that neutron detectors must respect to be useful. Some of these constraints, such as efficiency and gamma-ray sensitivity are common to all neutron counters while others, like timing resolution, dynamic range, and peak counting rate, depend on the applications.

The book guides experts, the nuclear science community, and young scholars through the physical processes and the required electronics in a way that is accessible for those not professionally involved in designing detector’s components and electronic circuits.

✦ Table of Contents

Foreword
Acknowledgments
Contents
Abbreviations
HFIR and SNS Instrument Names
Chapter 1: Neutron Scattering, Sources, and Instruments
1.1 Neutron Scattering: Introduction and Description
1.2 Neutron Sources and Neutron Production
1.3 The High Flux Isotope Reactor
1.4 Spallation Neutron Source
1.5 Neutron Instrument Components
References
Chapter 2: Neutron Detection Materials, Detector Properties, and Selection
2.1 Neutron Detection Materials
2.1.1 Helium-3
2.1.2 Boron-10
2.1.3 Lithium-6
2.2 Detector Properties
2.2.1 Efficiency
2.2.2 Counting Rate
2.2.3 Dead Time
2.2.4 Dynamic Range
2.2.5 Position Resolution
2.2.6 Time Resolution
2.2.7 Uniformity and Distortion
2.2.8 Gamma Rejection
2.2.9 Scintillation Decay Time
2.3 Detector Selection for Instruments
2.3.1 Instrument Classifications for Neutron Scattering
2.3.2 Diffractometers
2.3.3 Spectrometers
2.3.3.1 Triple Axis Spectrometers
2.3.3.2 Direct Geometry Spectrometers
2.3.3.3 Indirect Geometry Spectrometers
2.3.4 Small-Angle Neutron Scattering
2.3.5 Reflectometers
2.3.6 Neutron Imaging
References
Chapter 3: Gas-Based Detectors
3.1 Neutron Detection in Helium-3
3.1.1 Ionization Charge
3.1.2 Ionization Mode vs. Proportional Mode
3.1.3 Gas-Proportional Detectors
3.2 Linear Position-Sensitive Detectors
3.2.1 General Description
3.2.1.1 Introduction
3.2.1.2 Detector Tube Construction
3.2.1.3 Pulse-Height Spectrum
3.2.1.4 Count-Rate Effects
3.2.1.5 Circuitry for Position Determination
3.2.1.6 Correction for Voltage Offset Errors in Position Determination
3.2.1.7 Correction for Mismatched Gain Errors in Position Determination
3.2.1.8 Position Resolution and Noise Sources
3.2.1.9 Detector Module Construction
3.2.1.10 Detector Calibration and Characterization
3.2.2 LPSD Intrinsic Noise
3.2.2.1 Solution Using Instantaneous Values of Noise Voltages
3.2.2.2 Filtering of Noise by the Integrator
3.2.2.3 Calculation of RMS Noise Amplitudes
3.2.2.4 Noise Calculations for a Specific Detector
3.2.2.5 Experimental Test of Noise from Wire Resistance
3.2.3 The Attraction of the Central Wire to the Tube Wall for LPSD Tubes
3.2.3.1 Electrostatic Attraction of an Off-Center Wire to a Cylindrical Tube
3.2.3.2 Wire Deflection in Response to Side Forces
3.2.3.3 Scaling Rule
3.2.3.4 Numerical Simulation
3.2.3.5 Simulation Results
3.3 Single-Output Helium-3 Detector Tubes
3.4 Brookhaven National Laboratory 20 cm Multi-Wire Proportional Chamber
3.4.1 Details of Construction: Pressure Vessel and Fill Gas
3.4.2 Details of Construction: Wire Grids and Preamplifiers
3.4.3 Principle of Operation
3.5 Brookhaven National Laboratory 120 Curved Multiwire Proportional Chamber
3.5.1 Details of Construction: Pressure Vessel and Fill Gas
3.5.2 Details of Construction: Wire Grids and Preamplifiers
3.5.3 Principle of Operation
3.6 Denex Delay Line Detector
3.6.1 Details of Construction: Pressure Vessel and Fill Gas
3.6.2 Details of Construction: Wire Grids and Preamplifiers
3.6.3 Principle of Operation
3.7 Ordela Preamplifier per Wire Detector
3.7.1 Details of Construction: Pressure Vessel and Fill Gas
3.7.2 Details of Construction: Wire Grids and Preamplifiers
3.7.3 Principle of Operation
3.8 Beam Monitors
3.8.1 Introduction
3.8.2 Neutron Beam Monitors
3.8.3 Beam Monitors Used in Neutron Science Experiments
3.8.4 Operation Physics of the Multiwire Proportional Chamber Beam Monitors
3.8.5 Beam Monitor Performance Characteristics
3.8.5.1 Count Rate Limitations
3.8.5.2 Beam Monitor Neutron Absorption Probability
3.8.5.3 Beam Monitor Neutron Event Detection Probability
3.8.6 Mechanical Design of MWPC Beam Monitors
3.8.7 Beam Monitor Readout Electronics Overview
3.8.7.1 Preamplifier
3.8.7.2 Control Box
3.8.8 Beam Monitor Characteristic Tests
3.8.8.1 Beam Monitor Efficiency Test
3.8.8.2 Beam Monitor Attenuation Test
3.8.8.3 Beam Monitor TOF Test
3.8.9 Conclusion and Future Requirements
References
Chapter 4: Scintillator-Based Detectors
4.1 Anger Cameras for Neutron Detection
4.1.1 Anger Cameras
4.1.1.1 History
4.1.1.2 Principle of Operation
4.1.2 Design
4.1.2.1 Front-End Optics
Light Cone
Gamma Ray Discrimination
4.1.2.2 Electronic Boards
4.1.2.3 FPGA Board/Software
4.1.2.4 Communications
4.1.3 Performance
4.1.4 Anger Cameras at Beamlines
4.1.4.1 BL-3 SNAP
4.1.4.2 BL-11B MANDI and BL-12 TOPAZ
4.1.4.3 HB-3A DEMAND
4.1.5 Improvements and Future Detectors
4.1.5.1 Resolution and Distortion
4.1.5.2 Gamma Ray Discrimination
4.1.5.3 Large Angle Coverage Detector
4.2 Neutron Imaging With Wavelength Shifting Fiber-Based Scintillation Detectors
4.2.1 Introduction
4.2.2 Principles of WLSF
4.2.3 Neutron Imaging Using WLSFs
4.2.3.1 Design Concepts
4.2.3.2 Position Encoding Methods
Analog Position Encoding
Digital Position Encoding
4.2.3.3 Fiber Coding
4.2.4 WLSF-Based Neutron Detectors at ORNL
4.2.5 Limitations and Potential Improvements
4.2.5.1 Scintillator Selection
4.2.5.2 WLSF Selection
4.2.5.3 Photosensor Selection
4.2.6 Current Status and Future Perspectives
4.2.7 Conclusion
References
Chapter 5: Other Detectors
5.1 Solid-State Neutron Beam Monitors
5.1.1 Principle of Operation
5.1.2 Detector Structure
5.1.3 Charge Generation
5.1.4 Biasing Conditions
5.1.5 Charge Collection
5.1.6 Solid-State Beam Monitor Efficiency
5.1.7 Signal Processing
5.1.8 TOF Spectrum
5.1.9 Beam Profiling
5.2 Semiconductor Neutron Detectors
5.3 Gaseous and Vacuum-Based Neutron Detectors
5.4 Image Plates and CCD-Based Neutron Detectors
5.5 Future Directions
References
Appendices
Appendix A: Reactor-Based Neutron Sources
Appendix B: Spallation-Based Neutron Sources
Appendix C: Derivation of EF for Direct Geometry Spectrometers
Appendix D: Derivation of EI and EF for Indirect Geometry Spectrometers
Index