Nuclear Batteries and Radioisotopes (eBook)

Preface 8
Contents 11
1 Introduction to Nuclear Batteries and Radioisotopes 15
Abstract 15
1.1 Fundamental Concepts 17
1.2 Nuclear Battery Design Considerations 23
1.2.1 Surface Interface 28
1.2.2 Volume Interface 30
1.3 Products from Ionizing Radiation: Heat and Ion Pairs 31
1.4 Geometrical Considerations in the Interface of an Isotropic Radiation Source to a Transducer 42
1.5 Methodology for Analysis 47
1.6 Summary 48
References 49
2 Radioisotopes 52
Abstract 52
2.1 Existing Radioisotope Supplies 52
2.1.1 Primordial Radioisotopes 53
2.1.2 Cosmogenic Radioisotopes 54
2.1.3 Manmade Radioisotopes 58
2.2 Radioisotope Production 62
2.2.1 Separation from Spent Fuel 63
2.2.1.1 Bismuth Phosphate Process 63
2.2.1.2 REDOX Process 66
2.2.1.3 PUREX Process 67
2.2.1.4 Other Processes 68
2.2.2 Separation from Natural Decay Chains 70
2.2.3 Production by Neutron Capture in a Reactor 76
2.2.4 Production by Accelerator 77
2.3 Cost of Radioisotopes 80
2.3.1 Cost of Separation 80
2.3.1.1 Cost Analysis 81
2.3.1.2 Dissolution, Mixing and Drying Equipment 81
2.3.1.3 Sunk Costs Considerations 82
2.3.2 Cost of Neutron Capture 82
2.3.3 Cost of Accelerator 86
2.4 Other Factors Influencing Cost 87
2.4.1 Safety 87
2.4.2 Software 87
2.4.3 Liquidity of Capital (Cash) 88
2.5 Isotopes Produced from the Manhattan Project 88
2.6 Mixed Oxide Fuel Fabrication Facility (MOX FFF) 88
2.7 Summary 89
References 90
3 Interactions of Ionizing Radiation with Matter and Direct Energy Conversion 93
Abstract 93
3.1 Ionizing Radiation Types and Ranges 93
3.1.1 Fission Fragments 93
3.1.2 Alpha Particles 99
3.1.3 Beta Particles and Positrons 102
3.1.4 Shielding Considerations 104
3.1.5 Rules of Thumb and Their Limitations 107
3.1.6 The Limitations of Average Beta Energy 109
3.1.7 What Types of Radiation Work Best with Nuclear Batteries and Why 114
3.2 Types of Transducers Used in Nuclear Batteries 114
3.2.1 Ion Pair Based 115
3.2.1.1 Efficiency of a Beta or Alpha Voltaic Cell Based on a Classic P-N Junction 117
Open Circuit Voltage (Voc) and the Driving Potential Efficiency 120
Depletion Zone Width and Current 123
3.2.2 Schottky Barriers 125
3.2.2.1 Liquid Semiconductor Schottky Barrier 127
3.2.3 Direct Charge Collection 128
3.2.3.1 The Ideal Match Between the Electric Field and the Ionizing Radiation 128
DCNB Design and Inefficiencies 129
Mismatch of the Electric Field with the Energy Distribution of the Particles 132
Effects of Angular Distribution 133
3.2.3.2 Reciprocating Cantilever 136
3.2.4 Indirect 137
3.2.4.1 Gaseous Fluorescers 138
PIDEC and RECS 138
Spectral Considerations for Excimer Emitters 139
Effect of Impurities on Excimer Efficiency 144
PIDEC 146
Nuclear-Driven Fluorescers 149
The Ion Source 150
Excimer Fluorescers 150
The Photon Energy Converter 152
Photovoltaic Conversion of Narrowband Fluorescence 152
Wide Band-Gap Photovoltaic Materials 156
Gas 159
Solid Sources that Can Mimic Gas 159
Solid-State 159
3.2.5 Solid-State Emitter and PV 161
3.2.5.1 Phosphors 162
3.2.6 Hybrid Solid-State Emitter 167
3.2.7 Heat Based 168
3.2.7.1 Seebeck Effect and RTG 168
3.2.7.2 Thermoionics 171
3.2.7.3 Thermophotovoltaics 180
3.3 Summary 183
References 184
4 Power Density Dilution Due to the Interface of the Isotope with the Transducer 188
Abstract 188
4.1 Introduction 189
4.2 Phase of the Radioisotope 191
4.2.1 Radioisotope in Solid Phase 191
4.2.2 Radioisotope in Liquid Phase 193
4.2.3 Radioisotope in Gaseous Phase 194
4.2.4 Gaseous-like Radioisotopes 198
4.3 Phase of the Transducer 200
4.3.1 Solid Phase Transducer 200
4.3.2 Liquid Phase Transducer 200
4.3.3 Gas Phase Transducer 203
4.3.4 Plasma Phase Transducer 203
4.4 Surface Interface 203
4.4.1 Methods of Forming Surface Sources 204
4.4.1.1 Thin Foil 204
4.4.2 Electroplating, Painting and Baking 206
4.4.3 Evaporation and Sputtering 206
4.4.4 Implanting 207
4.5 Charged Particle Escape Probability from Surface Sources 207
4.6 Scale Length Matching 208
4.6.1 Scale Length of Ionizing Radiation 209
4.6.1.1 Ion Scale Length 210
4.6.1.2 Beta Scale Length 210
4.6.2 Scale Length of Transducer 216
4.6.2.1 Scale Length of P-N Junctions 216
4.7 Geometrical Considerations 220
4.8 Power Density Dilution Factors for Surface Interfaces 226
4.9 Power Density Dilution Factors for Volume Interfaces 227
4.10 Summary 228
References 229
5 Efficiency Limitations for Various Nuclear Battery Configurations 232
Abstract 232
5.1 Basics of Nuclear Battery Design 232
5.1.1 Transducer Efficiencies 233
5.1.1.1 p-n Junctions 233
The Use of Ionizing Radiation from Nuclear Reactions to Produce Electron-Hole Pairs in a p-n Junction 235
Temperature Effects in p-n Junctions 238
5.1.1.2 The Use of Ionizing Radiation from Nuclear Reactions to Produce Electron-Hole Pairs in a Schottky Barrier 238
5.1.1.3 The Use of Photons to Produce Electron-Hole Pairs in a p-n Junction 239
5.1.2 Direct Charge Nuclear Battery (DCNB) 241
5.2 Radiation Damage 246
5.3 Health and Safety 251
5.3.1 Nuclear Regulatory Commission Rules and Regulations 251
5.3.2 Po-210 Poisoning 254
5.3.3 NASA RTG Safety 256
5.4 System Efficiencies and Power Density 263
5.4.1 Alphavoltaics Analysis 264
5.4.2 Betavoltaics Analysis 269
5.4.3 PIDEC Analysis 271
5.5 Analysis of Problems in Nuclear Battery Literature 280
5.6 Summary 291
References 293
6 Potential Applications for Nuclear Batteries 296
Abstract 296
6.1 Successful Applications 296
6.1.1 Pacemakers 297
6.1.2 Deep Space Probes 297
6.1.3 Curiosity Rover 300
6.1.4 Remote Power Applications 300
6.1.5 Other 301
6.2 Military Missions 302
6.2.1 Light Weight Portable Nuclear Batteries 303
6.2.2 MEMS 309
6.3 MEMS 309
6.3.1 Drones 309
6.3.2 Nano-Power Systems 310
6.3.3 Fission Reactors 313
6.4 Summary 314
References 315
Appendix A: Range Calculations 317
Appendix B: Beta Spectra 322
Appendix C: Theoretical Nuclear Battery Design Concepts 346
Appendix D: Ranges for Alpha Emitters 352
Index 359