Effect of O\(_2\) into N\(_2\) Afterglows in RF and Corona Discharges

Abstract

The afterglows in N₂-O₂ gas mixtures have been previously described: N - atoms titration by NO[A-1], oxygen in impurity in N₂ at reduced gas pressure and at atmospheric gas pressure. The  and O-atoms density versus the O₂ percent from 1 to 4% into N₂ in HF flowing afterglow (at 7 Torr, 0.5 slpm, 150w) was strongly decreasing for N-atoms from 15 to 210¹⁴cm^-3 and kept a nearly constant value for O-atoms density: 7-9 10¹⁴cm^-3, a value which is higher than the N-atom density in the range 2 - 10% O₂ into N₂.

In RF afterglows, it was studied the effect of O-atoms and O₂ molecules when O₂ was introduced into N₂ before or after the plasma (8 Torr, 1 slpm, 100 W ). It is concluded that a quenching of N₂ active species by O-atoms more effective than with O₂ in the early and late afterglows.

At N₂ the atmospheric gas pressure of Corona Plasmas with O₂ impurity, it has been measured the density of the N₂O¹S excimer equal to about 10¹²cm^-3, largely less than the N and N₂ (A) densities: (5-7) 10¹⁴cm^-3 .