Preface ........................................................ xi
List of Contributors ......................................... xiii
1 The Detection Problem ........................................ 1
1 Explosive Detection Technology - The Impetus .............. 1
2 The Problem ............................................... 3
3 Detection Technologies .................................... 4
2 Explosives: The Threats and the Materials ................... 11
1 Devices and Explosives ................................... 11
2 Fundamentals of Explosives ............................... 12
2.1 Usage of explosives ................................. 12
2.2 Detonation and deflagration ......................... 12
2.3 Primary and secondary explosives .................... 12
2.4 Energy release, explosive output, and critical
diameter ............................................ 13
2.5 Chemistry of some common explosives ................. 15
2.6 Military explosives ................................. 17
2.7 Plastic explosives .................................. 18
2.8 Commercial explosives ............................... 18
2.9 Propellants ......................................... 19
2.10 Terrorist use of homemade explosives ................ 20
2.11 Peroxide explosives ................................. 21
2.12 Exotic explosives ................................... 21
2.13 Energetic salts ..................................... 22
2.14 Non-solid explosives ................................ 23
3 Implications for Detection ............................... 23
3 Detection of Explosives by Dogs ............................. 27
1 Introduction ............................................. 27
2 The Scientific Basis of Explosives Detection by Dogs ..... 28
2.1 What do dogs detect? ................................ 29
2.2 Sensitivity ......................................... 31
2.3 Specificity ......................................... 32
2.4 Dynamic range ....................................... 34
2.5 Generalization ...................................... 34
2.6 Duty cycle .......................................... 35
2.7 Robustness .......................................... 36
3 Training, Evaluation and Maintenance ..................... 37
4 Conclusions .............................................. 38
4 Colorimetric Detection of Explosives ........................ 41
1 Introduction ............................................. 41
2 Nitroaromatic Explosives ................................. 43
3 Nitrate Esters and Nitramines ............................ 45
4 Improvised Explosives Not Containing Nitro Groups ........ 49
5 Peroxide-Based Explosives ................................ 49
6 Urea Nitrate ............................................. 52
7 Field Tests .............................................. 53
5 Nuclear Technologies ........................................ 59
1 Basis for Detection ...................................... 59
2 Physics Underlying Nuclear Detection Methods ............. 60
2.1 Detection principles ................................ 60
2.2 Neutron sources ..................................... 65
2.3 Detectors ........................................... 67
3 Survey of Neutron-Based Detection Approaches ............. 72
3.1 Thermal neutron activation .......................... 72
3.2 Fast neutron activation ............................. 73
3.3 Fast neutron-associated particle .................... 75
3.4 Pulsed fast neutron transmission spectroscopy ....... 76
3.5 Pulsed fast neutron analysis ........................ 78
4 Survey of Non-Neutron-Based Nuclear Detection Methods .... 80
4.1 Nuclear resonance absorption ........................ 80
4.2 Nuclear quadrupole resonance ........................ 81
4.3 Nuclear resonance fluorescence ...................... 82
5 Problems with the Use of Nuclear Techniques for
Explosive Detection ...................................... 83
5.1 Field deployment of neutron sources ................. 83
5.2 Health hazards because of radiation ................. 83
5.3 Material activation ................................. 84
5.4 Neutron shielding ................................... 84
5.5 Public perception of radiation ...................... 84
6 Summary .................................................. 84
6 X-ray Technologies .......................................... 89
1 Introduction ............................................. 89
2 X-ray Physics ............................................ 90
2.1 Production of X-rays ................................ 90
2.2 Attenuation of X-rays ............................... 92
2.3 X-ray detectors ..................................... 96
2.4 Dual-energy X-ray ................................... 97
2.5 Effective atomic number ............................ 100
3 History of X-Ray Screening Technology ................... 102
3.1 Early history ...................................... 103
3.2 Linear array X-ray scanners ........................ 104
3.3 Material discrimination ............................ 105
3.4 Autorwated detection ............................... 106
3.5 Other advancements in X-ray screening .............. 109
3.6 Cargo scanners ..................................... 110
4 X-Ray Inspection Systems ................................ 111
4.1 Conventional transmission .......................... 111
4.2 Dual-energy transmission systems ................... 116
4.3 Multi-view systems ................................. 120
4.4 Scatter-based systems .............................. 121
4.5 Coherent X-ray scatter ............................. 123
5 Conclusion .............................................. 127
7 CT Technologies ............................................ 131
1 Introduction ............................................ 131
2 Features of X-ray CT Imaging ............................ 131
3 Principles of CT Imaging ................................ 133
3.1 Single-slice CT .................................... 133
3.2 Multislice CT ...................................... 137
3.3 Dual-energy CT ..................................... 138
4 CT Scanner Operation .................................... 140
5 CT Scanner Design Considerations ........................ 144
8 Analysis and Detection of Explosives by Mass
Spectrometry ............................................... 147
1 Introduction ............................................ 147
2 Trace Analysis of Explosives ............................ 150
2.1 Analysis of explosives by GC/MS .................... 150
2.2 Analysis of explosives by LC/MS .................... 151
3 Detection of Hidden Explosives .......................... 164
4 Conclusions ............................................. 168
9 Advances in Ion Mobility Spectrometry of Explosives ........ 171
1 Introduction ............................................ 171
2 Sampling, Portals, and Inlets ........................... 172
3 Ion Formation and Ion Sources ........................... 178
3.1 Gas phase ionization reactions ..................... 178
3.2 Ion sources ........................................ 181
4 Drift Tubes and Analyzer Development .................... 186
5 Field Asymmetric IMS and Differential Mobility
Spectrometry ............................................ 188
6 Pre-Separation with IMS ................................. 192
7 Calibrations and Vapor Sources .......................... 194
8 Applications of IMS for Explosives Determinations ....... 195
9 Future .................................................. 198
10 Detection of Explosives Using Amplified Fluorescent
Polymers ................................................... 203
1 Introduction fo Conjugated Polymers ..................... 203
2 Amplified Fluorescent Conjugated Polymers as Sensors .... 204
3 Electron Transfer fluorescence Quenching ................ 206
4 Polymer Design Principles for Solid-State Sensors ....... 208
4.1 Thin-film conjugated polymer sensors and
aggregation ........................................ 208
4.2 Other important design parameters for sensitivity
and selectivity - polymer 1 as a model ............. 210
5 Ultra-trace TNT Detection with Operable Devices ......... 213
6 Future Research Directions:Selected Examples ............ 216
6.1 Future device improvements:chromatographic
effects ............................................ 216
6.2 Future material and transduction improvements -
lasing sensors ..................................... 218
7 Conclusion .............................................. 220
11 Post-Blast Detection Issues ................................ 223
1 Objectives .............................................. 223
2 Controlling the Aftermath ............................... 224
2.1 Questions from the media and government leaders .... 224
2.2 Scene control ...................................... 224
2.3 Zoning ............................................. 225
3 Initial Scene Examination ............................... 226
3.1 Map the scene ...................................... 226
3.2 Was it a bomb? ..................................... 226
3.3 The right question(s) .............................. 226
3.4 Damage assessment .................................. 227
3.5 Debris collection .................................. 228
3.6 Explosives residues ................................ 228
3.7 Aircraft ........................................... 229
3.8 Quality assurance .................................. 230
3.9 Bomb scenes and mental stress ...................... 230
4 Laboratory Examinations ................................. 231
4.1 Work streams ....................................... 231
4.2 Functions .......................................... 231
4.3 Laboratory safety .................................. 231
4.4 Receipt ............................................ 232
4.5 Receipt of items for trace analysis ................ 232
4.6 Trace analysis ..................................... 233
4.7 Storage and disposal ............................... 238
5 Facsimiles and Tests .................................... 238
6 Prediction of Explosive Effects ......................... 239
7 Summary ................................................. 241
12 Explosives and Dangerous Chemicals: Constitutional
Aspects of Search and Seizure .............................. 245
1 Introduction ............................................ 246
2 The Fourth Amendment .................................... 246
2.1 Elements of Fourth Amendment ....................... 247
3 The Bill of Rights ...................................... 251
4 The Fourteenth Amendment ................................ 251
5 The Law on Search and Seizure ........................... 251
5.1 Background: Fourth Amendment jurisprudence ......... 251
5.2 Evidentiary search and seizure ..................... 252
5.3 Search and seizure exceptions ...................... 255
5.4 Remedies ........................................... 261
6 Surveillance Technology ................................. 262
6.1 New surveillance technology ........................ 262
6.2 Tracking ........................................... 263
6.3 Telephonic wiretap ................................. 263
6.4 Internet software .................................. 264
6.5 Data mining ........................................ 264
7 Terrorism ............................................... 265
7.1 Explosives ......................................... 265
8 Technical Security Administration - Administrative
Searches and Seizures ................................... 269
8.1 Transport security ................................. 269
8.2 Explosives detection ............................... 270
8.3 Passenger profiling ................................ 271
9 USA Patriot Act ......................................... 272
9.1 Creation ........................................... 272
9.2 Conflicts between Patriot Act and civil rights ..... 274
9.3 Discussion ......................................... 274
9.4 Application ........................................ 275
10 Conclusion .............................................. 275
Index ......................................................... 283
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