Joint Effect of Shock-Wave Heating and Laser Photolysis for the Generation of Active Atoms and Radicals in a Wide Temperature Range

An experimental setup combining shock-wave heating and pulsed laser photolysis of the investigated gas mixtures has been created. The system allows for the generation of active atom and radical concentrations over a wide range of temperatures and pressures, opening new opportunities for detailed studies in chemical kinetics and combustion. Atomic oxygen concentrations in the range of 10¹²–10¹⁴ cm^–3 have been obtained under the influence of an Ar–F excimer laser at a wavelength of 193 nm on a shock-heated mixture of O₂ + Ar at temperatures ranging from 700 to 1500 K and pressures of 2–4 bar. The absolute concentrations of O atoms have been measured with high accuracy using atomic resonance absorption spectroscopy at a wavelength of 130.5 nm. It has been demonstrated that the developed system can be successfully used for precision studies of the oxidation kinetics of various fuels in the temperature range characteristic of practical energy conversion systems, whose operating cycles include combustion processes.