Gaseous Electronics and Gas Lasers

Preface

Acknowledgements


1. Introduction


1.1 Gas Discharge Species


1.1.1 Neutrals


1.1.2 Charged Particles


1.1.3 Excited Species and Photons


1.2 Interactions Between Species


1.3 Basic Characterization of Electrons


1.3.1 Debye Shielding


1.3.2 Plasma Frequency


1.4 References


2. Elementary Theory of a Gas Discharge


2.1 The Langevin Equation


2.2 Mobility, Conductivity and Dielectric Constant


2.3 Energy Balance, Electron Temperature and Energy Relaxation


2.4 References


3. Collisions


3.1 Cross Section, Mean Free Path and Collision Frequency


3.2 Classical Scattering by a Central Force


3.2.1 Electron-Molecule Hard-Sphere Collisions


3.2.2 Coulomb Collision Scattering


3.2.3 Differential Scattering Cross Section


3.2.4 Scattering Cross Section


3.2.5 Attractive Potentials


3.3 Inelastic Collisions


3.3.1 Ionization


3.3.2 Electronic Excitation


3.3.3 Vibrational and Rotational Excitation of Molecules


3.3.4 Recombination


3.3.5 Attachment


3.4 References


4. Distribution Functions and the Boltzmann Equation


4.1 Averages and Collisional Rates


4.2 Equilibrium Distributions and Rates


4.2.1 Collisional Rates for a Maxwellian Distribution


4.2.2 Detailed Balance and Inverse Processes


4.3 The Boltzmann Equation


4.3.1 The Collision Integral


4.4 Expansion of the Boltzmann Equation for an Applied Electric Field


4.4.1 Expansion of the Collision Integral


4.5 Distribution Function for an Applied Electric Field - Elastic Collisions Only


4.5.1 Constant Collision-Frequency Case


4.5.2 Constant Mean Free-Path Case


4.6 Distribution Functions when E1ectron-Electron Co11isions are Important


4.7 Distribution Functions when Inelastic Collisions Dominate


4.7.1 The Boltzmann Equation Including Inelastic Processes


4.7.2 The Distribution Function for Atomic Gases


4.7.3 The Distribution Function for Molecular Gases


4.7.4 Rate-Process Calculations


4.8 Approximate Analytic Techniques for Determining Distribution Functions and Rates


4.8.1 Two and Three-Electron Group Models


4.8.2 The "Upflux" Approach


4.9 References


5. Transport Coefficients


5.1 Electrical Conductivity


5.2 Mobility


5.3 Diffusion


5.4 The Einstein Relation and Characteristic Energy


5.5 Corrections to the Langevin Equation


5.6 References


6. The Fluid Equations


6.1 The Continuity Equation


6.2 The Momentum-Conservation Equation


6.3 The Energy-Conservation Equation


6.4 References


7. Electron-Density Decay Processes


7.1 Diffusion


7.1.1 Rectangular Geometry


7.1.2 Cylindrical Geometry


7.1.3 Spherical Geometry


7.1.4 Ambipo1ar Diffusion


7.1.5 Transition Diffusion


7.1.6 Diffusion in Multi-Species Discharges


7.1.7 Diffusion Cooling


7.2 Recombination


7.2.1 Radiative Recombination


7.2.2 Three-Body Recombination


7.2.3 Dissociative Recombination


7.2.4 Electron Temperature Dependence of Recombination


7.2.5 Electron Density Decay in Plasmas with Diffusion and Recombination


7.3 Attachment


7.3.1 Radiative Attachment


7.3.2 Dissociative Attachment


7.3.3 Three-Body Attachment


7.4 References


8. DC Discharges - The Positive Column


8.1 Diffusion-Dominated Discharges


8.1.1 Electron Temperature in the Diffusion-Dominated Discharge


8.1.2 Longitudinal Electric Field in the Diffusion-Dominated Discharge


8.1.3 Deviations from the Simple Theory


8.2 Attachment-and Recombination-Dominated Discharges


8.3 Constriction and Instability of the Positive Column


8.4 References


9. Excited Species


9.1 Radiative1y Decaying Species


9.2 Co11isionally Decaying Species


9.2.1 The Neon (1s5) Metastables Species


9.2.2 The Helium (23S) Metastable Species


9.3 References


10. Atomic Neutral Gas Lasers


10.1 The Laser Concept


10.1.1 Population Inversion and Gain


10.1.2 Small Signal Gain, Saturation Intensity and Amplitude of Oscillation


10.1.3 Power Available from a Laser Amplifier


10.2 The Helium-Neon Laser


10.2.1 Rate Equations, Population Inversion and Gain


10.2.2 Similarity Laws for He-Ne Lasers


10.2.3 Cascade Interactions


10.3 Electron Collision-Pumped Lasers


10.4 References


11. Ion Lasers


11.1 Metal Vapor Lasers


11.2 Rare-Gas Ion Lasers


11.2.1 Argon Ion Lasers


11.3 References


12. Molecular Gas Lasers


12.1 Molecular Structure and Nomenclature


12.1.1 Rotation


12.1.2 Vibration


12.1.3 Vibration-Rotation


12.1.4 Electronic Structure


12.2 The Molecular Nitrogen Laser


12.3 The Molecular Hydrogen Laser


12.4 CO2 Lasers


12.4.1 Upper Laser-Level Excitation Mechanisms


12.4.2 Laser-Level Relaxation Mechanisms


12.4.3 Electron Energy Distributions and Fractional Power Transfer


12.4.4 Laser Kinetics Model


12.5 Excimer Lasers


12.5.1 Rare-Gas Excimers


12.5.2 Rare Gas-Monohalide Excimers


12.5.3 Mercury-Halide Lasers


12.6 References

Appendix A. Expansion of the Boltzmann Equation in Spherical Harmonics

Index