ИСТИНА

Experiments on measuring the concentration of free electrons by microwave interferometers of various designs and electric currents to cylindrical probes were conducted on a shock tube in reflected shock waves. Plasma was formed by chemical ionization reactions during the oxidation of various hydrocarbons. The cylindrical conductors of the Leсher line of the microwave interferometer were used as electric probes for measuring total currents. A quantitative comparison of the results of determining the concentration of free electrons by micro- wave interferometers with the different input systems of probing microwave radiation, as well as the concentration of free electrons deter- mined from the total currents to cylindrical probes was carried out. Various lean mixtures of methane and acetylene with oxygen diluted with argon were investigated. A detailed kinetic model of chemical ionization during the oxidation of simplest hydrocarbons was proposed. Comparison of the results of calculations of the concentration of free electrons with the results of microwave measurements showed their good agreement. This made it possible to compare the result obtained using our microwave interferometer with similar results of other authors obtained by a microwave interferometer of a different design operating at higher frequencies.