Experimental study of a small scale COIL using a jet type generator of singlet oxygen

Abstract

ABSTRACT We report on studies of a 5 cm gain length chemical oxygen-iodine laser (COIL) energized by a jet-type singlet oxygengenerator (JSOG) are presented. For 10 mmole/s of Cl2 flow rate, output power of 132 W with chemical efficiency of14.5% were obtained without a water vapor trap. 163 W and 18% were achieved when cooled (173 K) He was introduceddownstream of the JSOG; under these conditions the small signal gain was estimated to be 0.32% cm1. 190 W and10.5% were obtained for 20 mmole/s of Cl2 flow rate. Replacing He by N2 as a buffer gas resulted in a 13% powerdecrease only. The main key for increasing the chemical efficiency of a COIL without a water vapor trap for a giveniodine-oxygen mixing system is found to be high oxygen pressure and low water vapor pressure inside the reaction zoneof the JSOG. The last goal was achieved by optimizing the composition and temperature of the basic hydrogen peroxidesolution (BHP). The experimental results are discussed and related to the composition and flow conditions of the gaseousreactants and of the BHP. We also report on preliminary results of efficient COIL operation without primary buffer gasusing rectangular nozzles with iodine injection in the throat.Keywords: supersonic COILs, chemical oxygen-iodine lasers.