# Gaseous Electronics and Gas Lasers

## 1st Edition

**Authors:**Blake E. Cherrington

**Editors:**D. Ter Haar

**eBook ISBN:**9781483278964

**Imprint:**Pergamon

**Published Date:**1st January 1979

**Page Count:**282

## Description

Gaseous Electronics and Gas Lasers deals with the fundamental principles and methods of analysis of weakly ionized gas discharges and gas lasers. The emphasis is on processes occurring in gas discharges and the analytical methods used to calculate important process rates. Detailed analyses of a variety of gas discharges are presented using atomic, ionic, and gas lasers as primary illustrations.

Comprised of 12 chapters, this book begins with some initial categorization of gas discharge species and an overview of their interactions. The discussion then turns to an elementary theory of a gas discharge; inelastic collisions; distribution functions and the Boltzmann equation; and transport coefficients. Subsequent chapters focus on the fluid equations; electron-density decay processes; excited species; atomic neutral gas lasers; molecular gas lasers; and ion lasers. The important electron loss processes that determine the behavior of a plasma when the source and loss terms balance are also examined.

This monograph will be of value to graduate students, practitioners, and researchers in the fields of physics and engineering, as well as to professionals interested in working with weakly ionized discharges.

## Table of Contents

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

## Details

- No. of pages:
- 282

- Language:
- English

- Copyright:
- © Pergamon 1979

- Published:
- 1st January 1979

- Imprint:
- Pergamon

- eBook ISBN:
- 9781483278964