Chemical Generation Of Atomic Iodine Research Articles

Generation of atomic iodine via fluorine for chemical oxygen–iodine laser

A method of the chemical generation of atomic iodine for a chemical oxygen–iodine laser (COIL) using atomic fluorine as a reaction intermediate was studied experimentally. This method is based on the reaction between F 2 and NO providing F atoms, and the reaction of F with HI resulting in iodine atoms generation. Atomic iodine was produced with efficiency exceeding 40% relative to initial F 2 flow rate. This efficiency was nearly independent on pressure and total gas flow rate. The F atoms were stable in the reactor up to 2 ms. An optimum ratio of the reactants flow rates was F 2:NO:HI = 1:1:1. A rate constant of the reaction of F 2 with HI was determined. The numerical modelling showed that remaining HI and IF were probably consumed in their mutual reaction. The reaction system was found suitable for employing in a generator of atomic iodine with its subsequent injection into a supersonic nozzle of a COIL.

Atomic Iodine Generation via Fluorine Atoms for Chemical Oxygen-Iodine Laser

Chemical generation of atomic iodine for a chemical oxygen-iodine laser (COIL) was investigated experimentally. In the two-step reaction mechanism, molecular fluorine reacts with nitrogen oxide and formed fluorine atoms react then with hydrogen iodide to iodine atoms. The efficiency of this process was studied in dependence on mixing conditions, flow rate of reacting gases and pressure in reactor. A maximum concentration of atomic iodine was obtained at approximately equimolar ratio of reacting gases (F2, NO and HI), which agrees well with the stoichiometry of production reactions. A shortage of any reacting gases limits the rate of atomic iodine formation. An excess of F2 relative to NO at a simultaneous deficiency of HI had a most detrimental effect on atomic iodine production. High concentrations of atomic iodine (5-8 × 1015 cm-3) were achieved by this method at pressures 4-9 kPa, which are sufficient for a COIL operation. This makes it possible to use the above method as a source of iodine atoms and their injection into the primary flow of singlet oxygen in COIL.

Chemical generation of iodine atoms

Abstract The chemical generation of atomic iodine using a chemical combustor to generate the atomic fluorine intermediate, from the reaction of F2 + H2, followed by the production of atomic iodine, from the reaction of F + HI, was investigated. The maximum conversion efficiency of HI into atomic iodine was observed to be approximately 75%, which is in good agreement with the theoretical model. The conversion efficiency is limited by the formation of iodine monofluoride at the walls of the combustor where the gas phase temperature is insufficient to dissociate the IF.

Development of the Chemical Oxygen-Iodine Laser (COIL) with chemical generation of atomic iodine

This article addresses the development of a Chemical Oxygen-Iodine Laser (COIL) with alternative chemical ways of generating atomic iodine. Injection of atomic iodine as opposed to molecular iodine has the potential to improve the COIL efficiency. This paper describes two chemical methods for generating iodine atoms based on the gas phase reactions of hydrogen/deuterium iodide with fluorine or chlorine atoms, which are also produced chemically. Simplified one-dimensional gas dynamic modeling that describes the stream-wise profiles of species concentrations within both reaction systems is used to gain a theoretical understanding of both reaction systems under COIL conditions. The modeling results are used for the design of an experimental device and the interpretation of experimental data. The first experimental investigation studies the production of iodine atoms produced from reactions of Cl with HI. Atomic iodine yields of 70–100% in nitrogen are obtained, and the gain on the I(2P1/2)–I(2P3/2) transition in a flow of singlet oxygen is measured.

Chemical generation of atomic iodine for the chemical oxygen–iodine laser. II. Experimental results

A new method for the chemical generation of atomic iodine intended for use in a chemical oxygen–iodine laser (COIL) was investigated experimentally. The method is based on the fast reaction of hydrogen iodide with chemically produced chlorine atoms. Effects of the initial ratio of reactants and their mixing in a flow of nitrogen were investigated experimentally and interpreted by means of a computational model for the reaction system. The yield of iodine atoms in the nitrogen flow reached 70–100% under optimum experimental conditions. Gain was observed in preliminary experiments on the chemical generation of atomic iodine in a flow of singlet oxygen.

Chemical generation of atomic iodine for chemical oxygen–iodine laser. I. Modelling of reaction systems

The mathematical modelling of reaction systems for chemical generation of atomic iodine is presented. This process is aimed to be applied in the chemical oxygen–iodine laser (COIL), where it can save a substantial part of energy of singlet oxygen and so increase the laser output power. In the suggested method, gaseous reactants for I atoms generation are admixed into the COIL primary gas flow containing singlet oxygen. Two reaction systems were proposed, based on the reaction of hydrogen iodide with chemically generated atomic fluorine or chlorine. It was found that the reaction path via Cl atoms better matches the experimental conditions of COIL with a yield of atomic iodine of up to 67%. As a result of modelling, a suitable reaction system and design of experimental arrangement for the effective production of atomic iodine in laser conditions were found.