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The mechanism of I2 dissociation in supersonic chemical oxygen-iodine lasers (COILs) is studied applying kinetic-fluid dynamics modeling, where pathways involving the excited species I2(X 1Σg+,10≤v<25), I2(X 1Σg+,25≤v≤47), I2(A′ 3Π2u), I2(A 3Π1u), O2(X 3Σg-,v), O2(a 1Δg,v), O2(b 1Σg+,v), and I(2P1/2) as intermediate reactants are included. The gist of the model is adding the first reactant and reducing the contribution of the second as compared to previous models. These changes, recently suggested by Azyazov, et al. [J. Chem. Phys. 130, 104306 (2009)], significantly improve the agreement with the measurements of the gain in a low pressure supersonic COIL for all I2 flow rates that have been tested in the experiments. In particular, the lack of agreement for high I2 flow rates, which was encountered in previous models, has been eliminated in the present model. It is suggested that future modeling of the COIL operation should take into account the proposed contribution of the above mentioned reactants. [ABSTRACT FROM AUTHOR]

Presents a study which examined the efficiency of chemical oxygen-iodine laser oscillators. Evaluation of chemical oxygen-iodine laser performance; Types of efficiencies introduced in the examination; Results and discussion.

Presents a study that described the design and operation of an oxygen-iodine chemical laser. Features of the laser; Analysis of the variation of laser power with run time; Calculation of the power extraction efficiency of the laser.

Presents a study which generated metastable oxygen in bubble column reactor for chemically pumped iodine lasers. Details of experimental techniques used; Information on the technical application of bubble column reactor; Calculation of the rate of absorption of chlorine and metastable oxygen.

Presents a study which developed a high-power chemical oxygen iodine laser system for industrial applications. Description of the laser system; Comparison of laser power to the effective oxygen power and the volume flow rate measured in the laser head; Correlation between saturation effect on laser power and effective oxygen power and the volume flow rate.

Presents a study that developed a highly efficient chemical oxygen iodine laser (COIL) with industrial uses. Oscillation of the COIL; Design concept of the system; Efficiencies that characterize the COIL.

We have investigated the interaction of regular and irregular structures - systems of shock waves, rarefaction waves, and turbulent layers - in a chemical oxygen-iodine laser. [ABSTRACT FROM AUTHOR]

The possibility of obtaining a high specific input energy in an electron-beam sustained discharge ignited in oxygen gas mixtures O2 : Ar : CO (or H 2) at the total gas pressures of 10–100 Torr was experimentally demonstrated. The specific input energy per molecular component exceeded ~6 kJ l -1 atm -1 (150 kJ mol -1) as a small amount of carbon monoxide was added into a gas mixture of oxygen and argon. It was theoretically demonstrated that one might expect to obtain a singlet delta oxygen yield of 25% exceeding its threshold value needed for an oxygen–iodine laser operation at room temperature, when maintaining a non-self-sustained discharge in oxygen gas mixtures with molecular additives CO, H2 or D2. The efficiency of singlet delta oxygen production can be as high as 40%. [ABSTRACT FROM AUTHOR]

Abstract, A new regime of chemical oxygen-iodine laser (COIL), high-pressure subsonic mode operation, was demonstrated using a jet-type singlet oxygen generator (SOG). The laser output power of 342W with chemical efficiency of 20.9% was obtained at the Cl[sub 2] flow rate of 18 mmol/s and the operating pressure of 6.4 Torr in the laser cavity. The specific energy was 3.1 J/1 which was tour times higher than our supersonic device, and was comparable to the highest value for the supersonic regime. The experimental results were in good agreement with the numerical simulation results. [ABSTRACT FROM AUTHOR]

The efficient power operation in a chemical oxygen-iodine laser for subsonic and supersonic modes has been demonstrated. It is shown that the substitution of the buffer gas N2 by CO2 does not cause any significant variation in the dependence of the output power on the degree of dilution of the active medium. The maximum power was 581 W for the flow rate of molecular chlorine 22 mMol/s that corresponds to a chemical efficiency of ηchem=29%. [ABSTRACT FROM AUTHOR]

Improving the chemical efficiency of the supersonic chemical oxygen-iodine laser (COIL) is a key issue for the design of devices for both defense and industrial applications. Efficiencies around 30% for the supersonic COIL have been the state of the art in the last decade. Here, we report the achievement of a record (40%) for the chemical efficiency of the supersonic COIL. More specifically, we show that by carefully studying and optimizing the operation of the chemical generator, the mixing of heavy and light molecules in the gas phase and the optical extraction efficiency, we have approached the theoretical limit for the chemical efficiency. [ABSTRACT FROM AUTHOR]

Presents a correction to the study 'Long Term Stability in the Operation of a Chemical Oxygen-Iodine Laser for Industrial Use,' which was published in the 1989 issue of the 'Journal of Applied Physics.'

Develops pulsed iodine laser driven by a chemical oxygen generator. Demonstration of energy deposition; Extraction of the pulsed laser by high-energy density pulsed pumping; Estimation of the specific energy.

Review: 47 refs. [ABSTRACT FROM AUTHOR]

Generation of atomic iodine by dissociation of CF3I in a RF discharge was studied experimentally in a configuration ready for direct use of the method in an oxygen-iodine laser. The discharge was ignited between coaxial electrodes with a radial distance of 3.5 mm in a flowing mixture of 0.1-0.9 mmol s[?]1 of CF3I and 0.5-6 mmol s[?]1 of buffer gas (Ar, He) at a pressure of 2-3 kPa. The discharge stability was improved by different approaches so that the discharge could be operated up to a RF source limit of 500 W without sparking. The gas leaving the discharge was injected into the subsonic or supersonic flow of N2 and the concentration of generated atomic iodine and gas temperature were measured downstream of the injection. An inhomogeneous distribution of the produced iodine atoms among the injector exit holes was observed, which was attributed to a different gas residence time corresponding to each hole. The dissociation fraction was better with pure argon as a diluting gas than in the mixture of Ar-He, although the variation in the Ar flow rate had no significant effect on CF3I dissociation. The dissociation fraction calculated from the atomic iodine concentration measured several centimetres downstream of the injection was in the range 7-30% when the absorbed electric energy ranged from 200 to 4000 J per 1 mmol of CF3I. The corresponding values of the fraction of power spent on the dissociation decreased from 8% to 2% and the energy cost for one iodine atom increased from 30 to 130 eV. Due to a possible high rate of the atomic iodine loss by recombination after leaving the discharge, these values were considered as lower limits of those achieved in the discharge. [ABSTRACT FROM AUTHOR]

Cooling the flow in the electric discharge excited oxygen-iodine laser is used to increase gain in the supersonic cavity and laser power. The flow is cooled by injecting helium precooled in a liquid nitrogen bath downstream of the iodine injector. The highest gain achieved is 0.21% cm[?]1 over the gain path of 10 cm. Laser power measured in a stable resonator with 99.9% and 99.0% reflectivity mirrors is 7.8 W. Gain measured downstream of the resonator during lasing remains high, 0.15% cm[?]1, 25% lower than gain without lasing, demonstrating that a small fraction of power available for lasing is coupled out. [ABSTRACT FROM AUTHOR]

The continuous wavelength chemical oxygen-iodine laser can be turned into pulse operation mode in order to obtain high energy and high pulse power. We propose an approach to produce iodine atoms instantaneously by pulsed gas discharge with the assistance of spark pre-ionization to achieve the pulsed goal. The influence of spark pre-ionization on discharge homogeneity is discussed. Voltage-current characteristics are shown and discussed in existence of the pre-ionization capacitor and peaking capacitor. The spark pre-ionization and peaking capacitor are very helpful in obtaining a stable and homogeneous discharge. The lasing is achieved at the total pressure of 2.2-2.9kPa and single pulse energy is up to 180 mJ, the corresponding specific output energy is 1.0 J/L. [ABSTRACT FROM AUTHOR]

The pulsed chemical oxygen-iodine laser (COIL) development is aimed at many new applications. Pulsed electric discharge is most effective in turning COIL operation into the pulse mode by instant production of iodine atoms. A numerical model is developed for simulations of the pulsed COIL initiated by an electric discharge. The model comprises a system of kinetic equations for neutral and charged species, electric circuit equation, gas thermal balance equation and the photon balance equation. Reaction rate coefficients for processes involving electrons are found by solving the electron Boltzmann equation, which is re-calculated in a course of computations when plasma parameters changed. The processes accounted for in the Boltzmann equation include excitation and ionization of atoms and molecules, dissociation of molecules, electron attachment processes, electron-ion recombination, electron-electron collisions, second-kind collisions and stepwise excitation of molecules. The last processes are particularly important because of a high singlet oxygen concentration in gas flow from the singlet oxygen chemical generator. Results of numerical simulations are compared with experimental laser pulse waveforms. It is concluded that there is satisfactory agreement between theory and the experiment. The prevailing mechanism of iodine atom formation from the CF3I donor in a very complex kinetic system of the COIL medium under pulse discharge conditions, based on their detailed numerical modelling and by comparing these results both with experimental results of other authors and their own experiments, is established. The dominant iodine atom production mechanism for conditions under study is the electron-impact dissociation of CF3I molecules. It was proved that in the conditions of the experiment the secondary chemical reactions with O atoms play an insignificant role. [ABSTRACT FROM AUTHOR]