Combined Non-Self-Maintained Discharge in Air for Generating of Chemically Active Particles

摘要

Development of plasma technologies for problems of external and internal gas dynamics is impossible without the detailed studies of different discharge types both self maintained and non-self maintained improvement. These questions were discussed in many scientific forums recently. In particular, the longitudinal and transversal gas discharges in air were studied in air flows 1- 3 for their applications in applied problems of external and internal aerodynamics (ignition of flammable mixtures in air flows). In Ref 4 a combustion of hydrocarbon fuel under plasma assistance of formarions has been studied. In 5 the combined discharge in a supersonic air flow has been studied. Works 3,5 have shown that main plasma parameters (electron concentration Ne, and electron temperature Te) can be independently varied in wide ranges in the non-self maintained and combined discharges. This discharge property allows to selectively excite different molecules and create different radicals in the incident gas flows. Important property of these discharges is connected with a possibility of independent variation of a strength of an external electric field and of velocities of generation of plasma components by fast particles. The present paper is devoted to an investigation of active particle generating possibility in the plasma in conditions of the experiment 5 (external electric field strength is E-640 V/cm, electron flux at the 30 keV and current density of 0.12-0.27 A/cm2, typical size of investigated area 20-30 mm) in a supersonic air flow (Mach number M 1,2-1,6, static pressure Pst= 16 Torr) of our investigations are compared with other possible modes of air excitation.