Skobeltsyn Institute of Nuclear Physics
Lomonosov Moscow State University

One-dimensional self-consistent numerical model of direct current (DC) discharge in oxygen was elaborated. By using of this model we studied DC discharge in long tube of radius 0.6 cm at pressure 0.5-6 torr and current density 10-30 mA/cm2. Radial profiles of charged and neutral particles were calculated. The transition from electronegative to electropositive regime at changing of discharge current was considered. On the base of proposed geterogeneous kinetic model the dependence of oxygen atom quenching possibility on gas pressure was explained. Different quenching mechanisms for singlet oxygen O2(a1 delta g) were considered. For the first time, on the base of analysis of experimental data and results of modeling new mechanism of fast volumetric quenching of O2(a1 delta g) was suggested (O2(a1 delta)+ O(3P) + O2
-> O2 + O2 + O(3P)).