Determination of branching ratio and collisional mixing rate of potassium (52PJ) doublets following 193-nm photodissociation of potassium iodide in the presence of argon, helium, methane, and carbon dioxide

Abstract

Using a three-level kinetic model, we have accurately determined the branching ratio of the nascent photofragment K in the 5 2 P J fine-structure states following photodissociation of KI by a 193-nm excimer laser. The branching ratio of the K(5 2 P 3/2 ) component in the presence of Ar, He, CH 4 , and CO 2 is determined respectively to be 0.800, 0.798, 0.797, and 0.785 with ±1% accuracy. The model has liken into account the rapid energy transfer between the 5 2 P J doublets, thereby leading to a more accurate result than the measurement of direct fluorescence intensity ratios under the low-pressure condition