Determination of absolute O(3P) and O2(a1 Δ g) densities and kinetics in fully modulated O2 dc glow discharges from the O2(X3 Σ g −) afterglow recovery dynamics

摘要: A method is presented for the determination of absolute densities O(3P) atoms and O2(a1Δg) molecules in an O2 electrical discharge, which does not depend on any calibration procedure or knowledge optical transition strengths. It based observing recovery dynamics O2(X3Σg -) density afterglow a fully-modulated demonstrated dc glow discharge pure О2 at pressures 0.2-4 Torr. The time-resolved was measured by VUV absorption spectroscopy using monochromator branch DESIRS beamline Synchrotron SOLEIL, but this methodology could be used with another measurement technique. During active depleted combination dissociation, excitation into metastable states (principally (a1Δg) ) gas heating/dilation. After extinction, progressively recovers to its initial (before discharge) value, three distinct time-constants due to: i) cooling (fast), ii) atom recombination (intermediate), iii)O2(a1Δg) quenching (slow). can separated easily, allowing loss kinetics determined, as well their mole fractions steady-state discharge. Both mole-fractions increase current (up highest studied, 40 mA) pass through maxima pressure 1 Torr, reaching 16.5% 8%, respectively. are principally lost borosilicate tube surface, probability ~8x10-4, nearly independent (in contrast previous observations [1] . were also IR emission spectroscopy. In late agrees dynamics, corresponding surface ~2.2x10-4. faster than later afterglow, indicating that it quenched O atoms.