Chemical Lasers

1. Introduction.- 2. Fundamentals of Chemical Laser Kinetics.- 2.1 Qualitative Analysis of Chemical Laser Operation.- 2.1.1 Specific Power of Coherent Radiation.- 2.1.2 Laws Governing Population Inversion.- Development in the Case of Chemical Pumping.- 2.1.3 Energy Characteristics and Their Dependence on the Physico-Chemical Reaction Mechanism.- 2.2 Nonequilibrium Excitation in Chemical Reactions.- 2.3 Population Inversion and Amplification of Radiation in Yibrational-Rotational Transitions.- 2.3.1 Amplification Conditions..- Total and Partial Population Inversion.- 2.3.2 Gain.- 2.4 Elementary Vibrational Relaxation Processes.- 2.4.1 Experimental Data.- 2.4.2 Theoretical Studies.- 2.5 General Equations Describing Physico-Chemical.- Processes Occurring in the Laser Medium.- 2.5.1 Radiative Processes.- 2.5.2 Chemical Kinetics.- 2.5.3 Vibrational-Rotational Kinetics.- 2.5.4 Energy Conservation Equation.- 2.5.5 Generation of Radiation in Gas Flows.- 2.6 Calculation of the Generation and Amplification of Radiation in Multi-Level Chemical Lasers in Quasistationary Approximation.- 3. Kinetics and Numerical Analysis of Chain-Reaction Chemical Lasers (Pulsed Mode).- 3.1 Brief Review of the Theory.- 3.2 H2-F2 System.- 3.2.1 Hydrogen-Fluorine Reaction Mechanism..- Explosion Limits.- 3.2.2 Mathematical Model of the Hydrogen-Fluoride Laser (HFL).- 3.2.3 Calculation of the Effect of Basic Factors on the Energy Characteristics and Emission Dynamics of HFL in the Rotational-Translational Equilibrium Approximation.- 3.2.4 Effect of Rotational Nonequilibrium on Laser Emission Spectrum, Dynamics, and Energy.- 3.2.5 Modeling of HFL with Allowance Made for Rotational Nonequilibrium and Anharmonicity of Lasing Molecules.- 3.3 D2 - F2 - CO2 System.- 3.3.1 Qualitative Discussion of the Kinetic Scheme of Chemical Pumping Involving Energy Transfer.- 3.3.2 Elementary Process Kinetics and Laser Performance Calculation Procedures.- 3.3.3 Calculation of the Effect of Basic Factors on the Energy Characteristics of the DF-C02 Laser.- 3.3.4 Oscillation Excitation and Quenching Mechanism.- 3.3.5 Comparison Between the Energy Characteristics of the H2 - F2 and D2 - F2 - C02 Systems.- 3.3.6 On the Use of Energetic Chain Branching to Initiate Laser Emission with a High Quantum Yield.- 4. Pulsed Chemical Lasers.- 4.1 Requirements for the Parameters of Chemically-Pumped Pulsed Laser Systems.- 4.2 Initiation of Pulsed Chemical Lasers.- 4.2.1 Initiation Techniques.- 4.2.2 Engineering Aspects of Initiation.- 4.2.3 Questions Relating to the Homogeneity of Initiation and the Scaling of the Laser Medium Size.- 4.2.4 Comparison Between Flash-Photolysis and Electron-Beam Initiation Techniques.- 4.3 Laser Mixture Preparation Problems.- 4.4 Non-Chain-Reaction Pulsed Hydrogen-Fluoride Lasers..- 4.5 H2(D2)-F2 Lasers.- 4.5.1 Spectral and Temporal Characteristics.- 4.5.2 Effect of Oxygen and Mixture Preparation Techniques on Laser Performance Characteristics.- 4.5.3 Energy Characteristics.- 4.6 D2 - F2 - CO2 Lasers.- 4.7 Effect of Additives Accelerating the Hydrogen Fluorination Chain Reaction.- 4.8 Beam Divergence in Hydrogen-Fluoride Lasers.- 4.9 Pulsed Chemical Lasers Operating on Vibrational Overtones of HF and DF Molecules.- 4.10 Amplifier-Mode Operation of Pulsed Hydrogen-Fluoride Lasers.- 4.11 High-Repetition-Rate Operation of Chemical Lasers.- 4.12 Pulsed Chemical Lasers Based on Chain Reactions Other than the Hydrogen-Fluorine Reaction.- 4.13 Current Status of Pulsed Chemical Lasers.- 5. Continuous-Wave Chemical Lasers.- 5.1 Physical Principles of Operation of CWCL's.- 5.2 Purely Chemical Subsonic DF-CO2 Lasers.- 5.2.1 Basic Schemes. Experimental Situation.- 5.2.2 Simplified Theoretical Model..- Discussion of Experimental Data.- 5.2.3 Design-Basis Theoretical Model of Continuous-Wave DF-C02 Laser.- 5.3 Supersonic HF (DF) Lasers..- A Review of Experimental Work.- 5.3.1 Plasma-Generator Laser Version.- 5.3.2 Self-Contained Laser Version.- 5.4 Principal Power Performance Features of Supersonic CWCL's.- 5.4.1 Introductory Remarks. Flame Front Concept.- 5.4.2 Estimation of Scale Factors.- 5.4.3 Mixture-Pressure Dependence of Laser Energy Characteristics.- 5.4.4 Factors Limiting the Energy Performance of the "Cold"-Reaction HF Laser.- 5.5 Prospects for the Development of the DF-CO2 and HF CWCL's.- 5.5.1 Supersonic DF-CO2 Laser.- 5.5.2 HF CWCL with Chain Excitation Mechanism.- 5.6 Other Types of CWCL's.- 5.6.1 Hydrogen-Halide Lasers.- 5.6.2 Continuous-Wave Chemical CO Lasers.- 5.6.3 CWCL's with Energy Transfer to Polyatomic Molecules.- 5.7 Other Possible CWCL's Versions.- 5.7.1 Standing-Detonation-Wave HF Chemical Laser.- 5.7.2 16-(im Flowing-Gas DF-CO2 Chemical Laser.- 5.7.3 Continuous-Wave Optical Resonance Transfer HF Laser.- 6. Oxygen-Iodine Chemical Laser - a New Candidate for Engineering Applications.- 6.1 Experimental Results.- 6.2 Singlet Oxygen Generators.- 6.3 Kinetics of the Processes Occurring in the Active Medium of OICL.- 6.4 Pulsed OICUs.- 7. Photon Branching in Chain Reactions and IR-Radiation Initiated Chemical Lasers.- References.