Practical Gamma-ray Spectrometry

Cover
Title Page
Copyright
Contents
Preface to the Third Edition
Preface to the Second Edition
Preface to the First Edition
Internet Resources Within the Book
About the Website
Chapter 1 Radioactive Decay and the Origin of Gamma and X‐Radiation
	1.1 Introduction
	1.2 Beta Decay
		1.2.1 β− or Negatron Decay
		1.2.2 β+ or Positron Decay
		1.2.3 Electron Capture (EC)
		1.2.4 Multiple Stable Isotopes
	1.3 Alpha Decay
	1.4 Spontaneous Fission (SF)
	1.5 Exotic Decay Modes
	1.6 Gamma Emission
		1.6.1 The Electromagnetic Spectrum
		1.6.2 Some Properties of Nuclear Transitions
		1.6.3 Lifetimes of Nuclear Energy Levels
		1.6.4 Width of Nuclear Energy Levels
		1.6.5 Internal Conversion
		1.6.6 Abundance, Yield and Emission Probability
		1.6.7 Ambiguity in Assignment of Nuclide Identity
	1.7 Other Sources of Photons
		1.7.1 Annihilation Radiation
		1.7.2 Bremsstrahlung
		1.7.3 Prompt Gamma‐Rays
		1.7.4 X‐rays
			1.7.4.1 X‐ray Nomenclature
			1.7.4.2 X‐ray Energies
			1.7.4.3 X‐rays and Identification
			1.7.4.4 The Energy Widths of X‐rays
	1.8 The Mathematics of Decay and Growth of Radioactivity
		1.8.1 The Decay Equation
		1.8.2 Growth of Activity in Reactors
		1.8.3 Growth of Activity from Decay of a Parent
			1.8.3.1 Transient Equilibrium – t1/2 Parent > t1/2 Daughter
			1.8.3.2 Secular Equilibrium – t1/2 Parent ≫ t1/2 Daughter
			1.8.3.3 No Equilibrium – t1/2 Parent < t1/2 Daughter
			1.8.3.4 Multiple Parent–Daughter Relationships
	1.9 The Chart of the Nuclides
		1.9.1 A Source of Nuclear Data
		1.9.2 A Source of Generic Information
			1.9.2.1 Thermal Neutron Capture (n, γ)
			1.9.2.2 Fast Neutron Reactions, (n, p), etc.
			1.9.2.3 Fission Reactions (n, f)
	Practical Points
	Further Reading
Chapter 2 Interactions of Gamma Radiation with Matter
	2.1 Introduction
	2.2 Mechanisms of Interaction
		2.2.1 Photoelectric Absorption
		2.2.2 Compton Scattering
		2.2.3 Pair Production
	2.3 Total Attenuation Coefficients
	2.4 Interactions Within the Detector
		2.4.1 The Very Large Detector
		2.4.2 The Very Small Detector
		2.4.3 The ‘Real’ Detector
		2.4.4 Summary
	2.5 Interactions Within the Shielding
		2.5.1 Photoelectric Interactions
		2.5.2 Compton Scattering
		2.5.3 Pair Production
	2.6 Bremsstrahlung
	2.7 Attenuation of Gamma Radiation
	2.8 The Design of Detector Shielding
	Practical Points
	Further Reading
Chapter 3 Semiconductor Detectors for Gamma‐Ray Spectrometry
	3.1 Introduction
	3.2 Semiconductors and Gamma‐Ray Detection
		3.2.1 The Band Structure of Solids
		3.2.2 Mobility of Holes
		3.2.3 Creation of Charge Carriers by Gamma Radiation
		3.2.4 Suitable Semiconductors for Gamma‐Ray Detectors
		3.2.5 Newer Semiconductor Materials
	3.3 The Nature of Semiconductors
	3.4 The Manufacture of Germanium Detectors
		3.4.1 Introduction
		3.4.2 The Manufacturing Process
		3.4.3 Lithium‐Drifted Detectors
		3.4.4 Detector Configurations
		3.4.5 Absorption in Detector Caps and Dead Layers
		3.4.6 Detectors for Low‐Energy Measurements
		3.4.7 Well Detectors
	3.5 Detector Capacitance
		3.5.1 Microphonic Noise
	3.6 Charge Collection in Detectors
		3.6.1 Charge Collection Time
		3.6.2 Shape of the Detector Pulse
		3.6.3 Timing Signals from Germanium Detectors
		3.6.4 Electric Field Variations Across the Detector
		3.6.5 Removing Weak Field Regions from Detectors
		3.6.6 Trapping of Charge Carriers
		3.6.7 Radiation Damage
	3.7 Packaging of Detectors
		3.7.1 Construction of the Detector Mounting
		3.7.2 Loss of Coolant
		3.7.3 Demountable Detectors
		3.7.4 Electrical Cooling of Detectors
	3.8 Position‐Sensitive Detectors
		3.8.1 Segmentation
		3.8.2 Gamma‐Ray Tracking
	Practical Points
	Further Reading
Chapter 4 Electronics for Gamma‐Ray Spectrometry
	4.1 The General Electronic System
		4.1.1 Introduction
		4.1.2 Electronic Noise and Its Implications for Spectrum Resolution
		4.1.3 Pulse Shapes in Gamma Spectrometry Systems
		4.1.4 Impedance – Inputs and Outputs
		4.1.5 The Impedance of Cabling
		4.1.6 Impedance Matching
	4.2 Detector Bias Supplies
	4.3 Preamplifiers
		4.3.1 Resistive Feedback Preamplifiers
		4.3.2 Reset Preamplifiers
		4.3.3 The Noise Contribution of Preamplifiers
		4.3.4 The Rise Time of Preamplifiers
		4.3.5 Intelligent Preamplifiers and High‐Voltage Supplies
	4.4 Amplifiers and Pulse Processors
		4.4.1 The Functions of the Amplifier
		4.4.2 Pulse Shaping
		4.4.3 The Optimum Pulse Shape
		4.4.4 The Optimum Pulse Shaping Time Constant
		4.4.5 The Gated Integrator Amplifier
		4.4.6 Pole‐zero Cancellation
		4.4.7 Baseline Shift
		4.4.8 Pile‐up Rejection
		4.4.9 Amplifier Gain and Overview
	4.5 Resolution Enhancement
		4.5.1 New Semiconductor Materials
	4.6 Multichannel Analysers and Their Analogue‐to‐Digital Converters
		4.6.1 Introduction
		4.6.2 Pulse Range Selection
		4.6.3 The ADC Input Gate
		4.6.4 The ADC
			4.6.4.1 The Wilkinson ADC
			4.6.4.2 The Successive Approximation ADC
		4.6.5 MCA Conversion Time and Dead Time
		4.6.6 Choosing an ADC
		4.6.7 Linearity in MCAs
		4.6.8 Optimum Spectrum Size
		4.6.9 MCA Terms and Definitions
		4.6.10 A Short History of MCA Systems
		4.6.11 Simple MCA Analysis Functions
	4.7 Live Time Correction and Loss‐Free Counting
		4.7.1 Live Time Clock Correction
		4.7.2 The Gedcke–Hale Method
		4.7.3 Use of a Pulser
		4.7.4 Loss‐Free Counting (LFC)
		4.7.5 MCA Throughput
	4.8 Spectrum Stabilization
		4.8.1 Analogue Stabilization
		4.8.2 Digital Stabilization
	4.9 Coincidence and Anticoincidence Gating
	4.10 Multiplexing and Multiscaling
	4.11 Digital Pulse Processing Systems
	Practical Points
	Further Reading
Chapter 5 Statistics of Counting
	5.1 Introduction
		5.1.1 Statistical Statements
	5.2 Counting Distributions
		5.2.1 The Binomial Distribution
		5.2.2 The Poisson and Gaussian Distributions
	5.3 Sampling Statistics
		5.3.1 Confidence Limits
		5.3.2 Combining the Results from Different Measurements
		5.3.3 Propagation of Uncertainty
	5.4 Peak Area Measurement
		5.4.1 Simple Peak Integration
		5.4.2 Peaked‐Background Correction
	5.5 Counting Decision Limits
		5.5.1 Critical Limit (LC): ‘Is the Net Count Significant?’
		5.5.2 Upper Limit (LU): ‘Given That This Count Is Not Statistically Significant, What Is the Maximum Statistically Reasonable Count?’
		5.5.3 Confidence Limits
		5.5.4 Detection Limit (LD): ‘What Is the Minimum Number of Counts that I Can Be Confident of Detecting?’
		5.5.5 Determination Limit (LQ): ‘How Many Counts Would I Have to Have to Achieve a Particular Statistical Uncertainty?’
		5.5.6 Other Calculation Options
		5.5.7 Minimum Detectable Activity (MDA): ‘What Is the Least Amount of Activity I Can Be Confident of Measuring?’
		5.5.8 Uncertainty of the LU and MDA
		5.5.9 An Example by Way of Summary
	5.6 Special Counting Situations
		5.6.1 Non‐Poisson Counting
		5.6.2 Low Numbers of Counts
		5.6.3 Non‐Poisson Statistics Due to Pile‐up Rejection and Loss‐Free Counting
	5.7 Optimizing Counting Conditions
		5.7.1 Optimum Background Width
		5.7.2 Optimum Peak Width
		5.7.3 Optimum Spectrum Size
		5.7.4 Optimum Counting Time
	5.8 Uncertainty Budgets
		5.8.1 Introduction
		5.8.2 Accuracy and Precision
		5.8.3 Types of Uncertainty
		5.8.4 Types of Distribution
		5.8.5 Uncertainty on Sample Preparation
		5.8.6 Counting Uncertainties
		5.8.7 Calibration Uncertainties
			5.8.7.1 Nuclear Data Uncertainty
			5.8.7.2 Uncertainty on Efficiency Calibration Standards
		5.8.8 An Example of an Uncertainty Budget
	Practical Points
	Further Reading
Chapter 6 Resolution: Origins and Control
	6.1 Introduction
	6.2 Charge Production – ωP
		6.2.1 Germanium Versus Silicon
		6.2.2 Germanium Versus Sodium Iodide
		6.2.3 Temperature Dependence of Resolution
	6.3 Charge Collection – ωC
		6.3.1 Mathematical Form of ωC
	6.4 Electronic Noise – ωE
		6.4.1 Parallel Noise
		6.4.2 Series Noise
		6.4.3 Flicker Noise
		6.4.4 Total Electronic Noise and Shaping Time
	6.5 Resolving the Peak Width Calibration
	Practical Points
	Further Reading
Chapter 7 Spectrometer Calibration
	7.1 Introduction
	7.2 Reference Data for Calibration
	7.3 Sources for Calibration
	7.4 Energy Calibration
		7.4.1 Errors in Peak Energy Determination
	7.5 Peak Width Calibration
		7.5.1 Factors Affecting Peak Width
		7.5.2 Algorithms for Peak Width Estimation
		7.5.3 Estimation of the Peak Height
		7.5.4 Anomalous Peak Widths
	7.6 Efficiency Calibration
		7.6.1 Which Efficiency?
		7.6.2 Full‐energy Peak Efficiency
		7.6.3 Is an Efficiency Calibration Curve Necessary?
		7.6.4 The Effect of Source‐to‐Detector Distance
		7.6.5 Calibration Errors Due to Difference in Sample Geometry
		7.6.6 An Empirical Correction for Sample Height
		7.6.7 Effect of Source Density on Efficiency
			7.6.7.1 Corrections Based on Estimated Mass Attenuation Coefficients
			7.6.7.2 Empirical Correction for Self‐absorption
		7.6.8 Efficiency Loss Due to Random Summing (Pile‐up)
		7.6.9 True Coincidence Summing
		7.6.10 Corrections for Radioactive Decay
		7.6.11 Electronic Timing Problems
	7.7 Absolute Total Efficiency
	7.8 Mathematical Efficiency Calibration
		7.8.1 Empirical Mathematics
		7.8.2 Gamma Spectrometry Goes to Monte Carlo
		7.8.3 Do Monte Carlo‐Based Programs Work?
		7.8.4 Efficiency Calibration Software
		7.8.5 Using Monte Carlo to Assist Other Methods
			7.8.5.1 Efficiency Transfer
			7.8.5.2 The Representative Point (RP) Method
		7.8.6 The Virtual Gamma Spectrometry Laboratory
	Practical Points
	Further Reading
Chapter 8 True Coincidence Summing
	8.1 Introduction
	8.2 The Origin of Summing
	8.3 Summing and Solid Angle
	8.4 Spectral Evidence of Summing
	8.5 Validity of Close Geometry Calibrations
		8.5.1 The Effect of TCS on Efficiency Calibration
	8.6 Summary
	8.7 Summing in Environmental Measurements
	8.8 Achieving Valid Close Geometry Efficiency Calibrations
	8.9 TCS, Geometry and Composition
	8.10 Achieving ‘Summing‐Free’ Measurements
		8.10.1 Using the ‘Interpolative Fit’ to Correct for TCS
		8.10.2 Comparative Activity Measurements
		8.10.3 Using Correction Factors Derived from Efficiency Calibration Curves
		8.10.4 Correction of Results Using ‘Bodged’ Nuclear Data‘Bodge’ is British slang for a clumsy, messy, inelegant or inadequate solution to a problem.
	8.11 Mathematical Summing Corrections
	8.12 Software for Correction of TCS
		8.12.1 GESPECOR
		8.12.2 Calibrations Using Summing Nuclides
		8.12.3 TCS Correction in Spectrum Analysis Programs
	8.13 Using Coincidences for Measurement
	Practical Points
	Further Reading
Chapter 9 Computer Analysis of Gamma‐Ray Spectra
	9.1 Introduction
		9.1.1 Can You Trust the ‘black box’?
	9.2 Methods of Locating Peaks in the Spectrum
		9.2.1 Using Regions of Interest
		9.2.2 Locating Peaks Using Channel Differences
		9.2.3 Derivative Peak Searches
		9.2.4 Peak Searches Using Correlation Methods
		9.2.5 Checking the Acceptability of Peaks
	9.3 Library‐Directed Peak Searches
	9.4 Energy Calibration
	9.5 Estimation of the Peak Centroid
	9.6 Peak Width Calibration
	9.7 Determination of the Peak Limits
		9.7.1 Using the Width Calibration
		9.7.2 Individual Peak Width Estimation
		9.7.3 Limits Determined by a Moving Average Minimum
	9.8 Measurements of Peak Area
	9.9 Full‐Energy‐Peak Efficiency Calibration
	9.10 Multiplet Peak Resolution by Deconvolution
	9.11 Peak Stripping as a Means of Avoiding Deconvolution
	9.12 Spectrum Smoothing
	9.13 The Analysis of the Sample Spectrum
		9.13.1 Peak Location and Measurement
		9.13.2 Corrections to the Peak Area for Peaked‐Background
		9.13.3 Upper Limits and Minimum Detectable Activity
		9.13.4 Activity Estimations Using Efficiency Curves
		9.13.5 Comparative Activity Estimations
		9.13.6 Corrections Made by the Spectrum Analysis Program
			9.13.6.1 Random Summing Correction
			9.13.6.2 Other Corrections
	9.14 Nuclide Identification
		9.14.1 Simple Use of Lookup Tables
		9.14.2 Taking into Account Other Peaks
	9.15 The Final Report
	9.16 Setting up Nuclide and Gamma‐Ray Libraries
	9.17 Buying Spectrum Analysis Software
	9.18 Reading the Manual
	9.19 The Spectrum Analysis Programs Referred to in the Text
	Practical Points
	Further Reading
Chapter 10 Scintillation Spectrometry
	10.1 Introduction
	10.2 The Scintillation Process
	10.3 Scintillation Activators
	10.4 Lifetime of Excited States
	10.5 Temperature Variation of the Scintillator Response
	10.6 Scintillator Detector Materials
		10.6.1 Sodium Iodide – NaI(Tl)
		10.6.2 Bismuth Germanate – BGO
		10.6.3 Caesium Iodide – CsI(Tl) and CsI(Na)
		10.6.4 Undoped Caesium Iodide – CsI
		10.6.5 Barium Fluoride – BaF2
		10.6.6 Caesium Fluoride – CsF
		10.6.7 Rare‐Earth Halides – LaCl3(Ce), LaBr3(Ce) and CeBr3
		10.6.8 Other Scintillators
	10.7 Photomultiplier Tubes
	10.8 The Photocathode
	10.9 The Dynode Electron Multiplier Chain
	10.10 Photodiode Scintillation Detectors
	10.11 Silicon Photomultipliers
	10.12 Construction of the Complete Detector
		10.12.1 Detector Shapes
		10.12.2 Optical Coupling of the Scintillator to the Photomultiplier
	10.13 The Resolution of Scintillation Systems
		10.13.1 Statistical Uncertainties in the Detection Process
		10.13.2 Factors Associated with the Scintillator Crystal
		10.13.3 The Variation of Resolution with Gamma‐Ray Energy
	10.14 Electronics for Scintillation Systems
		10.14.1 High‐Voltage Supply
		10.14.2 Preamplifiers
		10.14.3 Amplifiers
		10.14.4 Multi‐channel Analysers and Spectrum Analysis
	10.15 Comparison of Sodium Iodide and Germanium Detectors
	Practical Points
	Further Reading
Chapter 11 Low Count‐Rate Systems
	11.1 Introduction
	11.2 Counting with High Efficiency
		11.2.1 MDA: Efficiency and Resolution
		11.2.2 MDA: Efficiency, Background and Counting Period
			11.2.2.1 Variation of BS, the Compton Continuum Due to the Sample, with Detector Size
			11.2.2.2 Variation of BE, the Environmental Background, with Detector Size
			11.2.2.3 The Effect of Resolution on Relative MDA and Count Period
			11.2.2.4 Is Bigger MUCH Better?
	11.3 The Effect of Detector Shape
		11.3.1 Low‐Energy Measurements
		11.3.2 Well Detectors
		11.3.3 Sample Quantity and Geometry
	11.4 Low Background Systems
		11.4.1 The Background Spectrum
		11.4.2 Low Background Detectors
		11.4.3 Detector Shielding
		11.4.4 The Graded Shield
		11.4.5 Airborne Activity
		11.4.6 The Effect of Cosmic Radiation
			11.4.6.1 Direct Interaction of Secondary Cosmic Radiation
			11.4.6.2 Cosmic Neutron‐Induced Activity
		11.4.7 Underground Measurements
	11.5 Active Background Reduction
		11.5.1 Compton Suppression Systems
			11.5.1.1 Design Considerations – Spectrometry (HPGe) Detector
			11.5.1.2 Design Considerations – Guard Detector
			11.5.1.3 Disadvantages of Compton Suppression
		11.5.2 Veto Guard Detectors
	11.6 Limiting Electronic Noise
	11.7 Ultra‐low‐Level Systems
	Practical Points
	Further Reading
Chapter 12 High Count‐Rate Systems
	12.1 Introduction
	12.2 Detector Throughput
	12.3 Preamplifiers for High Count Rate
		12.3.1 Energy Rate Saturation
		12.3.2 Energy Resolution
		12.3.3 Dead Time
	12.4 Amplifiers
		12.4.1 Time Constants and Pile‐up
		12.4.2 The Gated Integrator
		12.4.3 Pole‐Zero Correction
		12.4.4 Amplifier Stability – Peak Shift
		12.4.5 Amplifier Stability – Resolution
		12.4.6 Overload Recovery
	12.5 Digital Pulse Processing
	12.6 The ADC and MCA
	12.7 Dead Times and Throughput
		12.7.1 Extendable and Non‐extendable Dead Time
		12.7.2 Gated Integrators
		12.7.3 DSP Systems
		12.7.4 Theory Versus Practice
			12.7.4.1 Semi‐Gaussian Analogue Versus Digital Processor
			12.7.4.2 Gated Integrator Analogue Versus Digital Processor
		12.7.5 Modern DSPEC and LYNX Digital Systems
	12.8 System Checks
	Practical Points
	Further Reading
Chapter 13 Ensuring Quality in Gamma‐Ray Spectrometry
	13.1 Introduction
	13.2 Nuclear Data
	13.3 Radionuclide Standards
	13.4 Maintaining Confidence in the Equipment
		13.4.1 Setting Up and Maintenance Procedures
		13.4.2 Control Charts
		13.4.3 Setting Up a Control Chart
	13.5 Gaining Confidence in the Spectrum Analysis
		13.5.1 Test Spectra with Known Peaks
			13.5.1.1 The IAEA G1 Test Spectra
			13.5.1.2 The Sanderson Test Spectra
			13.5.1.3 Programs for Mathematically Creating Test Spectra
		13.5.2 Test Spectra Created by Counting
			13.5.2.1 The 1995 IAEA Test Spectra
			13.5.2.2 The 1997 NPL Test Spectra
			13.5.2.3 The 2002 IAEA Test Spectra
			13.5.2.4 The CTBTO Spectrum
			13.5.2.5 Finding Test Spectra
		13.5.3 Measuring Test Samples – Intercomparison Exercises
			13.5.3.1 NPL Environmental Radioactivity Proficiency Test Exercises
			13.5.3.2 The IAEA Proficiency Exercises
		13.5.4 Assessing Spectrum Analysis Performance
		13.5.5 Assessment of Intercomparison Exercises
	13.6 Maintaining Records
	13.7 Accreditation
	Practical Points
	Further Reading
Chapter 14 Gamma Spectrometry of Naturally Occurring Radioactive Materials (NORM)
	14.1 Introduction
	14.2 The NORM Decay‐Series
		14.2.1 The Uranium Series – 238U
		14.2.2 The Actinium Series – 235U
		14.2.3 The Thorium Series – 232Th
		14.2.4 Radon Loss
		14.2.5 Natural Disturbance of the Decay‐Series
	14.3 Gamma Spectrometry of the NORM Nuclides
		14.3.1 Measurement of 7Be
		14.3.2 Measurement of 40K
		14.3.3 Gamma Spectrometry of the Uranium/Thorium Series Nuclides
		14.3.4 Allowance for Natural Background
		14.3.5 Resolution of the 186 keV Peak
		14.3.6 Other Spectral Interferences and Summing
	14.4 Nuclear Data of the NORM Nuclides
	14.5 Measurement of Chemically Modified NORM
		14.5.1 Measurement of Separated Uranium
		14.5.2 Measurement of Separated Thorium
		14.5.3 ‘Non‐natural’ Thorium
		14.5.4 Measurement of Gypsum – A Cautionary Tale
	Practical Points
	Further Reading
Chapter 15 Applications
	15.1 Monitoring Radon in Water
		15.1.1 The Principle of the Method
		15.1.2 Detector Background
		15.1.3 Taking Water Samples
		15.1.4 Background Measurement
		15.1.5 Standardization
		15.1.6 Spectrum Acquisition
		15.1.7 Analysis of the Spectra
	15.2 Whole Body Counting
		15.2.1 The Background Problem
		15.2.2 Whole Body Counting Is Different
		15.2.3 Is There a Standard Body?
	15.3 Gamma Spectrometry and the CTBT
		15.3.1 Background
		15.3.2 The Global Verification Regime
		15.3.3 Nuclides Released in a Nuclear Explosion
		15.3.4 Measuring the Radionuclides
			15.3.4.1 Radioactive Particulate Monitoring
			15.3.4.2 Noble Gas Monitoring
		15.3.5 Current Status
	15.4 Gamma Spectrometry of Nuclear Industry Wastes
		15.4.1 Measurement of Isotopically Modified Uranium
		15.4.2 Measurement of Transuranic Nuclides
		15.4.3 Waste Drum Scanning
	15.5 Safeguards
		15.5.1 Enrichment Meters
		15.5.2 Plutonium Spectra
		15.5.3 Fresh and Aged Samples
		15.5.4 Absorption of Gamma‐Rays
		15.5.5 Hand‐held Monitors
	15.6 PINS – Portable Isotopic Neutron Spectrometry
	15.7 Gamma‐Ray Imaging
	15.8 Investigating the Structure of the Atomic Nucleus Using Gamma‐Ray Spectroscopy
	Further Reading
Chapter 16 Choosing and Setting Up a Detector, and Checking Its Specifications
	16.1 Introduction
	16.2 Setting Up a Germanium Detector System
		16.2.1 Installation – The Detector Environment
			16.2.1.1 The Counting Room
			16.2.1.2 The Electrical Supply
			16.2.1.3 Placement of the Detector
		16.2.2 Liquid Nitrogen Supply
		16.2.3 Shielding
		16.2.4 Cabling
		16.2.5 Installing the Detector
		16.2.6 Preparation for Powering‐up
		16.2.7 Powering‐up and Initial Checks
			16.2.7.1 Resistive Feedback Preamplifier Systems
			16.2.7.2 Transistor Reset (TRP) Preamplifier Systems
		16.2.8 Switching Off the System
	16.3 Optimizing the Electronic System
		16.3.1 General Considerations
		16.3.2 DC Level Adjustment and Baseline Noise
		16.3.3 Setting the Conversion Gain and Energy Range
		16.3.4 Pole‐zero (PZ) Cancellation
			16.3.4.1 Oscilloscope and Source
			16.3.4.2 Oscilloscope and Square Wave
			16.3.4.3 Automatic Correction
		16.3.5 Incorporating a Pulse Generator
			16.3.5.1 With a Resistive Feedback Preamplifier
			16.3.5.2 With a Transistor Reset Preamplifier
		16.3.6 Baseline Restoration (BLR)
		16.3.7 Optimum Time Constant
	16.4 Checking the Manufacturer\'s Specification
		16.4.1 The Manufacturer\'s Specification Sheet
		16.4.2 Detector Resolution and Peak Shape
		16.4.3 Detector Efficiency Coaxial Detectors
			16.4.3.1 Well Detectors
		16.4.4 Peak‐to‐Compton (P/C) Ratio
		16.4.5 Window Thickness Index
		16.4.6 Physical Parameters
	Practical Points
	Further Reading
Chapter 17 Troubleshooting
	17.1 Fault‐finding
		17.1.1 Equipment Required
		17.1.2 Fault‐finding Guide
	17.2 Preamplifier Test Point and Leakage Current
		17.2.1 Resistive Feedback (RF) Preamplifiers
		17.2.2 Transistor Reset and Pulsed Optical Reset Preamplifiers
	17.3 Thermal Cycling of the Detector
		17.3.1 The Origin of the Problem
		17.3.2 The Thermal Cycling Procedure
		17.3.3 Frosted Detector Enclosure
	17.4 Ground Loops, Pick‐up and Microphonics
		17.4.1 Ground Loops
		17.4.2 Electromagnetic Pick‐up
			17.4.2.1 Common Mode Rejection
			17.4.2.2 Mains Supply Problems
		17.4.3 Microphonics
			17.4.3.1 Mechanisms and Checks
			17.4.3.2 Solutions
	Practical Points
Appendix A Sources of Information
	A.1 Introduction
	A.2 Nuclear Data
		A.2.1 Sources of Nuclear Data
		A.2.2 Online Sources of Gamma‐Ray Emission Data
			A.2.2.1 DDEP
			A.2.2.2 Lara
			A.2.2.3 ENSDF
			A.2.2.4 NuDat 3.0
			A.2.2.5 IAEA
		A.2.3 Nuclear Databases Offline and in Print
	A.3 Internet Sources of Other Nuclear Data
	A.4 Chemical Information
	A.5 Further Research
	A.6 Practical Gamma‐Ray Spectrometry Website
Appendix B Gamma‐ and X‐Ray Standards for Detector Calibration
Appendix C X‐Rays Routinely Found in Gamma Spectra
Appendix D Gamma‐Ray Energies in the Detector Background and the Environment
Appendix E Chemical Names, Symbols and Relative Atomic Masses of the Elements
Glossary
Index
EULA