Gasdynamic Laser

ISBN-13: 9783642679292 / Angielski / Miękka / 2011 / 300 str.

S. A. Losev

Opis

This book deals with gasdynamic lasers (GDL)-high-energy sources of co- directional radiation. The theory and practice of gasdynamic lasers herent are based on three fields of modern science: quantum electronics, physico- chemical kinetics, and gasdynamics. This circumstance has determined the content of this book, which can be divided into two parts. The first four which occupy a considerable part of the book, prepare the reader chapters, for discussing the theoretical and experimental results of up-to-date GDL studies. The necessity of such a presentation is dictated by the fact that gasdynamic lasers can be a subject of interest for readers who are experts one of the mentioned fields, or those who have just begun studying in only GDLs. Such a representation is based on the experience gained by the author over several years in delivering lectures on this subject to students of Moscow State University. These lectures fonned the basis of the book, which can also be used as a text. The basic information on gasdynamic lasers is contained in the last two chapters of the book. These chapters give mathematical models of processes occurring in existing high-energy infrared GDLs (C0 GDLs, carbon monoxide 2 GDLs, etc. ), experimental results for these lasers, and also consider some possible new designs of GDLs. Of greatest interest in this respect are the attempts to create recombination electronic GDLs and plasmadynamic lasers.

Spis treści

1. Introduction.- 2. Basic Concepts of Quantum Electronics.- 2.1 Energy Levels and Quantum Transitions in Atoms and Molecules.- 2.2 Absorption and Amplification of Light in a Gas: Pumping and the Gain Coefficient.- 2.3 Laser Radiation in Resonators: Radiation Power.- 2.4 Unstable and Multipass Resonators.- 2.5 Active Medium Flow in a Cavity.- 3. Physico-chemical Gas Kinetics.- 3.1 Thermodynamic Properties of Gas Mixtures.- 3.2 Molecular Energy Exchange upon Collisions.- 3.3 Vibrational Transition Probabilities in Molecules.- 3.4 Vibrational Relaxation Kinetics.- 3.5 Vibrational Exchange Kinetics in CO2.- 3.6 Chemical Reactions in Gases.- 3.7 Processes in Heterogeneous Mixtures.- 4. Relaxation in Nozzle Gas Flow.- 4.1 One-Dimensional Steady-State Inviscid Gas Flow.- 4.2 Deactivation of Molecular Vibrations and Recombination of Atoms in Nozzles.- 4.3 Nozzle Contouring. Non-One-Dimensional Gas Flow.- 4.4 Effect of Viscosity. Gas Flow in Nozzle Array Wakes.- 4.5 Shock Tube with a Nozzle.- 5. Infrared CO2 Gasdynamic Laser.- 5.1 Kinetics of Processes in an Active Medium. Gain Coefficient.- 5.2 Small-Signal Gain Optimization.- 5.3 Output Power. Power Optimization.- 5.4 Combustion-Driven Gasdynamic Laser. Effect of Impurities.- 5.5 Supersonic Mixing Gasdynamic Lasers.- 5.6 Losses and Efficiency.- 5.7 Twin-Mode CO2 Laser.- 5.8 Creation of an Active Medium in Expansion Waves and Shock Waves.- 6. Gasdynamic Lasers with Other Active Medium.- 6.1 N2O and CS2 Gasdynamic Lasers.- 6.2 Carbon Monoxide Gasdynamic Laser.- 6.3 Gasdynamic Lasers for Far Infrared Spectral Region.- 6.4 Recombination Lasers on Electronic Transitions.- 6.5 Plasmadynamic Lasers.- Appendixes.- A. Derivation of Relations Between Einstein’s Coefficients.- B. Approximate Analytical Representation of the Voigt Functions.- C. Small-Signal Gain as a Function of Intensity.- D. Simplest Models of Molecular Motion.- E. Relations Between Concentrations of Mixture Components.- F. Material Balance Equations for Mixtures.- G. Chemical Equilibrium in a Gas Mixture.- H. Derivation of the Arrhenius Formula for the Rate Constant of a Chemical Reaction.- I. Chemical Kinetics Equations.- J. Relations for Gasdynamic Parameters of One-Dimensional Steady-State Flow.- K. Continuity Equation for an Individual Component in a Flow.- L. Implicit Method of the Numerical Solution of Differential Equations.- M. Relaxation of the System of Harmonic Oscillators in Nonisothermic Conditions.- List of the Most Used Symbols.- References.