Determination of rate constants for nonequilibrium reactions in gases with participation of electrons from ballistic experiments

Rates of Electron Attachment to Aluminum Oxides in Air-Xenon Mixtures

“…The analysis of [2] was performed using only data from experiments in which ablation of the model was not observed. However, a more careful analysis of the originally ignored experiments showed that among them there are experiments in which the dependences n e (x) are similar to the dependences obtained in [3,4] with Al ablation from spherical models moving in air. The experiments of [2] were performed using primarily Duralumin models coated with a thin copper layer to prevent Al ablation.…”

“…However, when the model separated from the sabbot in the separation compartment of the facility, this was accompanied in some cases by fracture of the coating, resulting in ablation and entry of aluminum particles into the wake. Therefore, it is necessary to take into account the information obtained in these experiments on nonequilibrium processes, the more so since there have been few direct ballistic experiments with ablation [1].…”

“…The nonequilibrium flow of a partly ionized gas in the wake behind a body flying at hypersonic velocity in a ballistic track is characterized by a change in the pressure from several atmospheres to several torrs, a change in the temperature from (7-8) · 10 3 to 300 K, and a reaction zone length above 1000 calibers of the body [1,2]. At hypersonic flight velocities, the ablation from the body surface can have a significant effect on the wake flow conditions, the chemical composition of the gas, and the spectral radiation intensity.…”

“…Aluminum and its alloys are widely used to manufacture the various units of plasmadynamic, aerodynamic, and ballistic facilities. Upon contact with high-temperature plasma flows, Al (T melt = 932 K) and its compounds enter the plasma because of their rather low melting point, thus changing its ionization and chemical composition [1,3]. Therefore, studying nonequilibrium physical and chemical processes in gases with participation of Al ions is of interest for both plasmadynamic research and the construction of theoretical models for elementary nonequilibrium processes [1,3].…”

“…Microwave measurements of electron concentration in wakes behind aluminum models flying in air at velocities of 3.4-5.7 km/sec and pressures of 10-80 torr are described in [3,4]. The results of these measurements were used to determine the rate constants of electron attachment to AlO and AlO 2 molecules and liquid or solid Al 2 O 3 particles.…”