Jane Lehr is a Professor of Electrical and Computer Engineering at the University of New Mexico. Prior positions were at Sandia National Laboratories and the Air Force Research Laboratory's Directed Energy Directorate. She is a Fellow of the IEEE, past President of the IEEE Nuclear and Plasma Sciences Society, and currently serves as their Society Fellow Evaluation Chair.

Pralhad Ron, PhD, is a scientist from the Bhabha Atomic Research Center (BARC), India. He retired as Head, Accelerator and Pulsed Power Division (APPD) of BARC. He served as Chairman, Steering Committee on Electron Beam Center, Kharghar, New Bombay, and Chairman, Safety Review Committee on Particle Accelerators in India constituted by the Atomic Energy Regulatory Board (AERB).

Preface xvii

About the Authors xxi

Acknowledgements xxiii

Introduction xxv

1 Marx Generators and Marx-Like Circuits 1

1.1 Operational Principles of Simple Marxes 1

1.1.1 Marx Charge Cycle 3

1.1.2 Marx Erection 4

1.1.2.1 Switch Preionization by Ultraviolet Radiation 5

1.1.2.2 Switch Overvoltages in an Ideal Marx 5

1.1.3 Marx Discharge Cycle 6

1.1.3.1 No Fire 7

1.1.3.2 Equivalent Circuit Parameters During Discharge 7

1.1.4 Load Effects on the Marx Discharge 10

1.1.4.1 Capacitive Loads 10

1.1.4.2 A Marx Charging a Resistive Load 14

1.2 Impulse Generators 15

1.2.1 Exact Solutions 15

1.2.2 Approximate Solutions 18

1.2.3 Distributed Front Resistors 19

1.3 Effects of Stray Capacitance on Marx Operation 19

1.3.1 Voltage Division by Stray Capacitance 20

1.3.2 Exploiting Stray Capacitance: The Wave Erection Marx 22

1.3.3 The Effects of Interstage Coupling Capacitance 23

1.4 Enhanced Triggering Techniques 26

1.4.1 Capacitive Back-Coupling 26

1.4.2 Resistive Back-Coupling 27

1.4.3 Capacitive and Resistively Coupled Marx 28

1.4.4 The Maxwell Marx 30

1.5 Examples of Complex Marx Generators 31

1.5.1 Hermes I and II 31

1.5.2 PBFA and Z 32

1.5.3 Aurora 33

1.6 Marx Generator Variations 33

1.6.1 Marx/PFN with Resistive Load 35

1.6.2 Helical Line Marx Generator 38

1.7 Other Design Considerations 39

1.7.1 Charging Voltage and Number of Stages 39

1.7.2 Insulation System 40

1.7.3 Marx Capacitors 41

1.7.4 Marx Spark Gaps 41

1.7.5 Marx Resistors 42

1.7.6 Marx Initiation 42

1.7.7 Repetitive Operation 44

1.7.8 Circuit Modeling 45

1.8 Marx-Like Voltage-Multiplying Circuits 45

1.8.1 The Spiral Generator 46

1.8.2 Time Isolation Line Voltage Multiplier 48

1.8.3 The LC Inversion Generator 49

1.9 Design Examples 54

References 57

2 Pulse Transformers 63

2.1 Tesla Transformers 63

2.1.1 Equivalent Circuit and Design Equations 64

2.1.2 Double Resonance and Waveforms 65

2.1.3 Off Resonance and Waveforms 66

2.1.4 Triple Resonance and Waveforms 67

2.1.5 No Load and Waveforms 68

2.1.6 Construction and Configurations 69

2.2 Transmission Line Transformers 71

2.2.1 Tapered Transmission Line 71

2.2.1.1 Pulse Distortion 71

2.2.1.2 The Theory of Small Reflections 72

2.2.1.3 Gain of a Tapered Transmission Line Transformer 77

2.2.1.4 The Exponential Tapered Transmission Line 77

2.3 Magnetic Induction 79

2.3.1 Linear Pulse Transformers 81

2.3.2 Induction Cells 81

2.3.3 Linear Transformer Drivers 83

2.3.3.1 Operating Principles 85

2.3.3.2 Realized LTD Designs and Performance 88

2.4 Design Examples 90

References 93

3 Pulse Forming Lines 97

3.1 Transmission Lines 97

3.1.1 General Transmission Line Relations 99

3.1.2 The Transmission Line Pulser 101

3.2 Coaxial Pulse Forming Lines 102

3.2.1 Basic Design Relations 102

3.2.2 Optimum Impedance for Maximum Voltage 104

3.2.3 Optimum Impedance for Maximum Energy Store 105

3.3 Blumlein PFL 105

3.3.1 Transient Voltages and Output Waveforms 107

3.3.2 Coaxial Blumleins 109

3.3.3 Stacked Blumlein 111

3.4 Radial Lines 113

3.5 Helical Lines 116

3.6 PFL Performance Parameters 117

3.6.1 Electrical Breakdown 118

3.6.2 Dielectric Strength 119

3.6.2.1 Solid Dielectric 119

3.6.2.2 Liquid Dielectric 119

3.6.3 Dielectric Constant 126

3.6.4 Self-Discharge Time Constant 126

3.6.5 PFL Switching 127

3.7 Pulse Compression 128

3.7.1 Intermediate Storage Capacitance 129

3.7.2 Voltage Ramps and Double-Pulse Switching 129

3.7.3 Pulse Compression on Z 131

3.8 Design Examples 134

References 141

4 Closing Switches 147

4.1 Spark Gap Switches 148

4.1.1 Electrode Geometries 150

4.1.2 Equivalent Circuit of a Spark Gap 154

4.1.2.1 Capacitance of the Gap 154

4.1.2.2 Resistance of the Arc Channel 155

4.1.2.3 Inductance of Arc Channel 156

4.1.3 Spark Gap Characteristics 158

4.1.3.1 The Self-Breakdown Voltage and Probability Density Curves 158

4.1.3.2 Delay Time 160

4.1.3.3 Rise Time (tr) 163

4.1.3.4 Burst-Mode Repetitively Pulsed Spark Gaps 164

4.1.3.5 Shot Life 166

4.1.3.6 Electrode Erosion 167

4.1.4 Current Sharing in Spark Gaps 172

4.1.4.1 Parallel Operation 172

4.1.4.2 Multichanneling Operation 173

4.1.5 Triggered Spark Gaps 177

4.1.5.1 Operation of Triggered Spark Gaps 177

4.1.5.2 Types of Triggered Switches 179

4.1.6 Specialized Spark Gap Geometries 195

4.1.6.1 Rail Gaps 195

4.1.6.2 Corona-Stabilized Switches 197

4.1.6.3 Ultra-Wideband Spark Gaps 199

4.1.7 Materials Used in Spark Gaps 201

4.1.7.1 Switching Media 201

4.1.7.2 Electrode Materials 203

4.1.7.3 Housing Materials 204

4.2 Gas Discharge Switches 204

4.2.1 The Pseudospark Switch 204

4.2.1.1 Trigger Discharge Techniques 206

4.2.1.2 Pseudospark Switch Configurations 207

4.2.2 Thyratrons 209

4.2.3 Ignitrons 213

4.2.4 Krytrons 214

4.2.5 Radioisotope-Aided Miniature Spark Gap 216

4.3 Solid Dielectric Switches 216

4.4 Magnetic Switches 217

4.4.1 The Hysteresis Curve 218

4.4.2 Magnetic Core Size 220

4.5 Solid-State Switches 221

4.5.1 Thyristor-Based Switches 223

4.5.1.1 Silicon-Controlled Rectifier 223

4.5.1.2 Reverse Switch-On Dynister 226

4.5.1.3 Gate Turn-Off Thyristor 226

4.5.1.4 MOS Controlled Thyristor 227

4.5.1.5 MOS Turn-Off Thyristor 228

4.5.1.6 Emitter Turn-Off Thyristor 229

4.5.1.7 Integrated Gate-Commuted Thyristor 230

4.5.2 Transistor-Based Switches 230

4.5.2.1 Insulated Gate Bipolar Transistor 230

4.5.2.2 Metal-Oxide-Semiconductor Field-Effect Transistor 231

4.6 Design Examples 231

References 235

5 Opening Switches 251

5.1 Typical Circuits 251

5.2 Equivalent Circuit 253

5.3 Opening Switch Parameters 254

5.3.1 Conduction Time 255

5.3.2 Trigger Source for Closure 255

5.3.3 Trigger Source for Opening 256

5.3.4 Opening Time 256

5.3.5 Dielectric Strength Recovery Rate 256

5.4 Opening Switch Configurations 256

5.4.1 Exploding Fuse 257

5.4.1.1 Exploding Conductor Phenomenon 258

5.4.1.2 Switch Energy Dissipation in the Switch 260

5.4.1.3 Time for Vaporization 261

5.4.1.4 Energy for Vaporization 262

5.4.1.5 Optimum Fuse Length 263

5.4.1.6 Fuse Assembly Construction 263

5.4.1.7 Multistage Switching 265

5.4.1.8 Performances of Fuse Switches 267

5.4.2 Electron Beam-Controlled Switch 267

5.4.2.1 Electron Number Density (ne) 269

5.4.2.2 Discharge Resistivity (¿) 271

5.4.2.3 Switching Time Behavior 271

5.4.2.4 Efficiency of EBCS 274

5.4.2.5 Discharge Instabilities 276

5.4.2.6 Switch Dielectric 277

5.4.2.7 Switch Dimensions 278

5.4.3 Vacuum Arc Switch 280

5.4.3.1 Mechanical Breaker 280

5.4.3.2 Magnetic Vacuum Breaker 282

5.4.3.3 Mechanical Magnetic Vacuum Breaker 283

5.4.4 Explosive Switch 284

5.4.5 Explosive Plasma Switch 286

5.4.6 Plasma Erosion Switch 286

5.4.7 Dense Plasma Focus 287

5.4.8 Plasma Implosion Switch 289

5.4.9 Reflex Switch 290

5.4.10 Crossed Field Tube 291

5.4.11 Miscellaneous 293

5.5 Design Example 294

References 295

6 Multigigawatt to Multiterawatt Systems 303

6.1 Capacitive Storage 305

6.1.1 Primary Capacitor Storage 305

6.1.2 Primary-Intermediate Capacitor Storage 306

6.1.3 Primary-Intermediate-Fast Capacitor Storage 307

6.1.3.1 Fast Marx Generator 308

6.1.4 Parallel Operation of Marx Generators 308

6.1.5 Pulse Forming Line Requirements for Optimum Performance 309

6.1.5.1 Peak Power Delivery into a Matched Load 309

6.1.5.2 Low-Impedance PFLs 310

6.1.5.3 Pulse Time Compression 310

6.2 Inductive Storage Systems 311

6.2.1 Primary Inductor Storage 311

6.2.2 Cascaded Inductor Storage 311

6.3 Magnetic Pulse Compression 313

6.4 Inductive Voltage Adder 315

6.5 Induction Linac Techniques 317

6.5.1 Magnetic Core Induction Linacs 317

6.5.2 Pulsed Line Induction Linacs 319

6.5.3 Autoaccelerator Induction Linac 322

6.6 Design Examples 323

References 328

7 Energy Storage in Capacitor Banks 331

7.1 Basic Equations 331

7.1.1 Case 1: Lossless, Undamped Circuit ¿ = 0 333

7.1.2 Case 2: Overdamped Circuit ¿ > 1 334

7.1.3 Case 3: Underdamped Circuit ¿ < 1 336

7.1.4 Case 4: Critically Damped Circuit ¿ = 1 336

7.1.5 Comparison of Circuit Responses 337

7.2 Capacitor Bank Circuit Topology 338

7.2.1 Equivalent Circuit of a Low-Energy Capacitor Bank 339

7.2.2 Equivalent Circuit of a High-Energy Capacitor Bank 340

7.3 Charging Supply 342

7.3.1 Constant Voltage (Resistive) Charging 342

7.3.2 Constant Current Charging 344

7.3.3 Constant Power Charging 345

7.4 Components of a Capacitor Bank 345

7.4.1 Energy Storage Capacitor 346

7.4.1.1 Capacitor Parameters 347

7.4.1.2 Test Methods 349

7.4.1.3...