<title>Experimental results on chemical generation of atomic iodine via Cl atoms for chemical oxygen-iodine laser</title>

Abstract

An alternative chemical way of atomic iodine generation for the chemical oxygen-iodine laser (COIL) was studied. This development was aimed at the laser power increase and simplification of the laser operation control. The method is based on the fast reaction of hydrogen iodide with chemically produced chlorine atoms. Kinetics of the process was studied in two types of the small-scale reactor and verified in the cavity of the supersonic COIL. The optimum yield of atomic iodine formation in the nitrogen atmosphere was very high (up to 100%) even in the COIL cavity and declined slightly with the distance from the supersonic nozzle throat. In the first experiments of atomic iodine generation in the flow of singlet oxygen in COIL, the gain of 0.18%.cm^-1was attained at rather low flow rate of atomic iodine (0.9 mmol.s^-1). In earlier investigation of COIL in the conventional arrangement with molecular iodine, no gain was achieved at the corresponding I₂ flow rate (0.45 mmol.s^-1). In the COIL with the new method of chemical generation of atomic iodine, a nearly constant gain along the flow axis was measured. It gives evidence that there is no strong quencher of excited atomic iodine in the reaction mixture. The published data represent the first results on gain measurement in the COIL with chemically generated atomic iodine. They promise an improvement of the COIL operation using the chemically generated atomic iodine.