Elements of Plasma Technology (eBook)

Dr. Chiow San Wong received the Ph.D. degree in plasma physics from the University of Malaya (UM), Kuala Lumpur, Malaysia, in 1983. He is Professor of physics and has been the Leader of UM’s Plasma Technology Research Group since 1992. His research focuses on plasma physics and applications, particularly pulsed radiation sources and their applications, plasma systems for material processing and surface treatment, and atmospheric discharges. He has published more than 230 papers, with more than 130 in refereed journals. Prof. Wong has been a Fellow of the Malaysian Academy of Sciences since 2007. He was a Fellow of the Alexander von Humboldt Stiftung in 1987 and the President of the Asian African Association for Plasma Training from 2004 to 2012. In 2005, he was the recipient of the Malaysian Toray Science and Technology Award for his contribution in the development of plasma technology in Malaysia.

Preface 6
Acknowledgments 7
Contents 8
1 Basic Concepts in Plasma Technology 11
Abstract 11
1.1 Plasma---The Fourth State of Matter 11
1.2 Collision 12
1.2.1 Elastic Collision 12
1.2.2 Inelastic Collision 14
1.3 Collision Cross-Section 15
1.4 Fundamental Processes in a Plasma 16
1.5 Some Consideration of Thermodynamic Properties of Plasma 17
1.6 Concept of Plasma Potential 19
1.7 Criteria of Plasma 20
1.8 Effect of Boundary in Plasma 21
1.9 Particle Transport Inside Plasma 22
2 Methods of Plasma Generation 25
Abstract 25
2.1 DC Electrical Discharge 25
2.1.1 Electrical Breakdown 25
2.1.2 The I--V Characteristic of Electrical Discharge 30
2.1.3 The Corona Discharge 32
2.1.4 The Glow Discharge 33
2.1.5 Hot Cathode Discharge 35
2.1.6 The Arc Discharge 36
2.2 AC (Radiofrequency) Discharge 39
2.3 Microwave Heating of Plasma 44
2.4 Pulsed Plasma Discharges 46
2.4.1 Pulsed Arc Discharge in High Pressure Flash Lamp 48
2.4.2 Inductive Model of Pulsed Discharge---Shock Heating 51
2.4.2.1 Shock Heating of Plasma 52
2.4.2.2 Pulsed Plasma Systems with Shock Heating as Plasma Heating Mechanism 56
References 58
General References 58
3 Plasma Diagnostic Techniques 59
Abstract 59
3.1 Electrical Measurements 59
3.1.1 Pulsed Current Measurement by Using the Rogowski Coil 60
3.1.1.1 Integration Using Passive Integrator 61
3.1.1.2 The Rogowski Coil as a Current Transformer 62
3.1.1.3 Calibration of the Rogowski Coil 63
3.1.2 Pulsed Voltage Measurements 65
3.1.2.1 The Resistive Voltage Divider 65
3.1.2.2 Capacitive Voltage Divider 67
3.1.2.3 Calibration of the Voltage Divider 69
3.1.3 Interpretation of the Current and Voltage Waveforms 69
3.2 Pulsed Magnetic Field Measurement 71
3.3 Plasma Spectroscopy 72
3.3.1 Plasma Radiation 72
3.3.1.1 Bremsstrahlung 72
3.3.1.2 Recombination 73
3.3.1.3 Radiative Decay 74
3.3.1.4 Some Useful Facts About Plasma Emission Spectrum 74
3.3.2 The Plasma Models 75
3.3.2.1 Local Thermodynamic Equilibrium (LTE) 75
3.3.2.2 Corona Equilibrium (CE) Model 77
3.3.3 Examples of Population Density Distribution and Plasma Spectra 78
3.3.3.1 Population Density Distribution 78
3.3.3.2 Examples of Plasma Emission Spectra 79
3.3.4 Optical Emission Spectroscopy of Plasma 80
3.4 The Langmuir Probe (Electric Probe) 84
3.4.1 Electron Temperature and Density Measurements of Steady State Plasmas 84
3.4.2 Dynamic Studies of a Flowing Plasma (or Charged Particle Beam) 86
3.5 X-ray Diagnostic Techniques 88
3.5.1 X-ray Absorption Filter 89
3.5.2 X-ray Detectors 90
3.5.2.1 Time-Resolved X-ray Detectors 90
3.5.2.2 Time-Integrated X-ray Imaging 97
3.6 Neutron Diagnostic Techniques 101
3.6.1 The Foil Activation Neutron Detector for Absolute Neutron Yield Measurement 101
3.6.1.1 Steady Source 102
3.6.1.2 Pulsed Neutron Source 103
3.6.2 The Detector Setup 105
3.6.3 Time-Resolved Neutron Pulse Measurement 106
References 108
General Reference 108
4 Some Examples of Small Plasma Devices 109
Abstract 109
4.1 The Electromagnetic Shock Tube [1] 109
4.1.1 Numerical Modeling of the Electromagnetic Shock Tube Dynamics 110
4.1.2 Experimental Measurements of Electromagnetic Shock Tube Dynamics 113
4.2 The Plasma Focus 115
4.2.1 Introduction 115
4.2.2 Characteristics of the Plasma Focus Discharge [3] 115
4.2.3 Design Consideration 116
4.2.4 X-ray Emission from the Plasma Focus Discharge 118
4.2.5 Neutron Emission 119
4.2.6 Particle Beam Emission 120
4.3 The Vacuum Spark 121
4.4 Scaled-Down Operation of Vacuum Spark---Flash X-ray Tube 122
4.5 The Pulsed Capillary Discharge 123
4.6 The 50 Hz Alternating Current (A.C.) Glow Discharge System 125
4.7 Atmospheric Pressure Dielectric Barrier Discharge 128
4.8 Wire Explosion System for Nano Powder Fabrication 129
References 131