Gaseous Dielectrics V presents the proceedings of the Fifth International Symposium on Gaseous Dielectrics, held in Knoxville, Tennessee on May 3-7, 1987. This book discusses the effective coupling between basic and applied research and technology achieved in this area.Organized into 12 chapters, this book begins with an overview of the status of theoretical calculations of excitation and ionization coefficients for electrons. This text then provides an extensive investigation into different phases of discharge development in electronegative gases. Other chapters consider the use of sulfur hexafluoride as a dielectric medium in rail systems and gas circuit breakers. This book reviews as well the primary requirements for a successful gas analysis program, with emphasis on measurement and interpretation methods. The final chapter deals with the progress in dielectric quality assurance of gas insulated substations (GIS), which has resulted from improved scientific knowledge of significant phenomena.This book is a valuable resource for electrical and electronics engineers.

Chapter 1: Basic Physics of Gaseous Dielectrics Excitation and Ionization Coefficients Discussion Laser-Enhanced Electron Attachment and Its Possible Application for Optical Switching Discussion Galvanooptical Measurement of Photodetachment from Negative Ion Swarms in Oxygen Discussion Electron Collision Cross Sections for C2F6 and N2O Discussion A Macroscopic Model of Electron Swarm Motion in Non-Equilibrium Regions Non-Equilibrium Description of Electrons in a Gas Influenced by Space-Time Varying Electric Fields Temperature Dependent Electron Transport and Rate Coefficient Studies for e-Beam-Sustained Diffuse Gas Discharge Switching Time Dependent Conductivity Studies of Electron Thermalisation in Simple GasesChapter 2: Basic Mechanisms Breakdown Mechanisms in Electronegative Gases Discussion Predischarge Development in N2 and SF6 at High Gas Pressures Discussion Effect of Temperature on the Uniform Field Breakdown Strength of Electronegative Gases Discussion The Influence of Thermal Ionization on Electrical Breakdown Discussion Contribution to a Unified Theory of the Leader Processes Discussion Mechanism of a Short Gap Breakdown Experimental Investigation of the Streamer to Leader Transition in SF6 Under Negative Polarity Modeling of Leader Branching in Electronegative Gases The Leader Inception Characteristics in Positive Sphere-Plane Air Gaps Velocity Measurements in Mixtures of SF6 and N2 in Non-Uniform Field Gaps Under Positive Impulse VoltageChapter 3: Gas Decomposition/Reacnons/Toxicity Decomposition of SF6 by Arc Discharge and the Determination of tne Reaction Product S2F10 Discussion Corona-Induced Decomposition of Dielectric Gases Discussion Investigations of the Toxicological Action of Spark-Decomposed SF6 in Mammalian Cells Discussion Degradation of the Dielectric Properties of SF6 Due to the Presence of Gaseous Impurities; Deviations of the "Paschen's Law" at High Pressures for Positive Polarity Discussion The Influence of Impurities on the Dielectric Strength of SF6 for Positive Polarity; The Nature of Initiatory Electrons Formation and Stability of SF5 and S2F10 SOF4 Production in Spark Breakdown of SF6/O2 Mixtures Assay of SF6 and Spark-Decomposed SF6 for Mutagenic Activity in the CHO/HGPRT Mammalian Cell SystemChapter 4: Diagnostics/Field Probes Gas Analysis as a Diagnostic Tool for Gas-Insulated Equipment Discussion On the Possibility of Diagnostics of GCB and GIS by Gas Chromatography Discussion On the Electrostatics of Probe Measurements of Surface Charge Densities Discussion Measurement of Accumulated Charge on Dielectric Surfaces with an Electrostatic Probe Discussion The Effect of Humidity on Space Charge Growth in Short Air Gaps Laser Probing of Air Gaps Under AC ConditionsChapter 5: Gases/Mixtures for GIS Transformers and Circuit Breakers Predicting the Breakdown Strength of Mixtures from Basic Data Discussion The Dielectric Strength of Dichlorotetrafluoroethane (1,2-C2Cl2F4) Determined in a Combined Swarm/Breakdown Study Discussion The Influence of Gaseous Admixtures to SF6 on the Corona Stabilized Regime at AC and at Positive Impulse Voltage Discussion Nonuniform Field Corona and Breakdown Characteristics of SF6/Freon Mixtures Discussion Effect of a Trichlorotrifluoroethane Vapor Additive on Dielectric Strength of SF6 Gas Measurement of the Figure of Merit M for Several Perfluorocarbon Gases Breakdown Voltage Measurement of Some Vapor-Mist DielectricsChapter 6: Gaseous Media for Discharge Chemistry and Etching/Coron Gaseous Media for Plasma Chemistry and Etching Discussion Practical Implications of Dry Plasma Processing Discussion Important Considerations for Optimizing Production Rates in RF Discharge Chemistry Discussion Negative DC Corona Discharge in SF6 for Highly Divergent Fields Discussion Calculation of Corona Onset Voltage with Space Charge Effect DC Corona Control in Coaxial Gas Insulating SystemsChapter 7: Gas Engineering for Pulsed Power and Switching Gas Engineering for Pulsed Power and Switching Discussion Penning Ionization Ternary Gas Mixtures for Diffuse Discharge Opening Switches Discussion Gas Mixtures for Spark Gap Closing Switches with Emphasis on Efficiency of Operation Discussion The Influence of Transverse Magnetic Fields on Glow Discharges in He/SF6 Gas Mixtures Discussion Analysis of the Cathode Fall of Glow Discharges in a He/SF6 Gas Mixture Gas Engineering Studies for High Pressure Self-Sustained Diffuse Discharge Closing Switches Diffuse Discharges in High-Pressure Mixtures of c-C4F8 and HeChapter 8: Gas Breakdown Under Steep-Fronted Voltages Statistical Breakdown Process in SF6 and Breakdown Voltage Calculations Discussion Formative Time Lags in SF6-N2 Gas Mixtures for Different Field Distribution Discussion Voltage-Time Characteristics of Impulse Breakdown in SF6 Gas Discussion Spacer Flashover Time Lags in SF6 Under Fast-Front Impulse Voltages Discussion Breakdown Volt-Time Characteristics in SF6 Mixtures for a Coaxial Cylinder Gap Effect of Field Divergence on the Lightning Impulse Breakdown of Rod-Plane Gaps in N2/SF6 Mixtures Free Particle Initiated Breakdown of SF6 Under Voltages of Different Time DependenceChapter 9: New Developments in Gas-Insulated Equipment/Gas Handling Development of ±500 kV HVDC Gas-Insulated Switchgears Discussion A Manufacturer's Experience in the Cyclic Use of SF6 Gas Discussion Volt-Time Curves of Disconnector-Generated Fast Transients inside GIS Discussion Insulation Characteristics of Separate Cooling Sheet Winding-Type Gas-Insulated Transformer Discussion Recovery Strength of SF6-Insulated Gaps Stressed by Double Lighting Impulse Voltages Conduction Currents in Gas-Insulated Switchgear for Low Level DC Stress Effects of Electrode Surface Roughness on Dark Current and Switching Impulse Breakdown Voltage in Compressed SF6 Gas Mixing Rates and Diffusion of Various Gases and Moisture into SF6Chapter 10: Gas/Insulator Interface/Flashover Surface Changes Induced by Low Kinetic Energy Products from Corona Discharge on Epoxy Resin in Air Discussion Avalanches Near a Dielectric Spacer in Nitrogen Gas Discussion Measurement of the Temporal Decay of Charges on Insulator Surfaces Discussion Effect of Ribs on Surface Discharge in SF6 Gas Discussion Application of ESCA in GIS Spacer Surface Analysis Discussion Study of the Charge Build-Up on Dielectrics Submitted to Corona Discharge and Ageing Effects Influence of 60 Hz AC Charging of Spacers on Subsequent Impulse Flashover in Compressed SF6 Surface Flashover of Polyester, Polypropylene, and Teflon Films in Low Pressure SF6 and N2 Media Research on Conductor-Plane Long-Gap Characteristics by Surface Discharge Analogy Model The Surface and Volume Effects of Interactions of Internal Partial Discharges with Solid DielectricsChapter 11: Quality Control in Testing Gas-Insulated Apparatus Fundamental Knowledge and the Testing of GIS Discussion Flashover Damage Test Procedure for Insulating Materials in Compressed SF6 Discussion Strength of Typical GIS Configurations with Special Reference to Composite and Combined Stresses Discussion Limits to Partial Discharge Detection Discussion Broad Band Pulse Detection Studies of Corona and Breakdown in Air, N2, O2, CO2, SF and SF6-N2 MixturesChapter 12: Reports of Discussion Groups Group Discussion on New Diagnostic Techniques Group Discussion on Gas-Insulated Transformers and DC GIS Group Discussion on Gas Engineering for Modern Technologies: Input from Basic ResearchList of ParticipantsPhotographs of ParticipantsAuthor Index