Influence of oxygen traces on kinetics of pure nitrogen post-discharge at decreased wall temperature

conference paper

English

The work presents results obtained during spectroscopic observations of DC flowing post-discharges of pure nitrogen plasma and nitrogen plasma containing low oxygen traces up to 0.2 %. The decaying plasma up to 50 ms was studied by the emission spectroscopy in the range of 300 - 850 nm. The discharge tube around the observation point (+- 3 cm) was immersed in liquid nitrogen. Three nitrogen spectral systems and NO-beta bands were identified in the investigated spectral region. The total gas pressure was 1000 Pa and the discharge current was kept at 200 mA. The relative populations of N_2 (B 3^Pi_g), N_2 (C ^3 Pi_u) and N_2^+ (B ^2 Sigma_u^+) states were calculated in the dependence on the post-discharge time. The results showed no simple dependence of vibrational populations on oxygen concentration, but generally the neutral states populations are increased whereas the ion population is decreased with the increasing oxygen concentration. The NO-beta emission increased more or less linearly with the increasing decay time and it was directly proportional to the oxygen concentration. Besides the kinetic processes known in pure nitrogen, the quenching of highly excited nitrogen molecules by atomic oxygen as well as their dissociation and energy transfer between nitrogen and NO species played the main role in the post-discharge kinetics.

nitrogen post-discharge, pink afterglow, post-discharge kinetics, optical spectroscopy, nitrogen-oxygen mixture

MAZÁNKOVÁ, V.; KRČMA, F.; SOURAL, I.

2007

24. 6. 2007

CIAM

Moskva

978-5-94588-047-4

Proeedings of 3rd International Symposium on Non-Equilibrium Processes, Plasma, Combustion and Atmospheric Phenomena

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