Influence of Argon Concentration on Kinetic Processes in Nitrogen-Argon Post-Discharge

conference paper

English

Besides various nitrogen based gas mixtures the nitrogen-argon mixture has a special position at the use in the plasma-chemical technologies. Study of kinetic processes in nitrogen-argon flowing post-discharge by optical emission spectroscopy was the aim of our experimental work. Our study compares wall temperature influence and influence of composition of nitrogen-argon mixture on kinetic processes. The active discharge was created in a Pyrex discharge tube with a 120 mm electrode distance at current of 120 mA. The system was pumped continuously by a rotary oil pump. The total pressure in the discharge tube during the experimental studies was constant (700 Pa) and it was measured by capacitance and Pirani gauges. The gas mixture composition was varied from pure nitrogen up to 1 % of nitrogen in argon and its flow velocity was kept constant at about 11.5 m.s-1. The spectra were measured by Jobin Yvon monochromator TRIAX 550 with CCD detector. The emitted light was lead to the entrance slit of the monochromator by the multimode quartz optical fiber movable along the discharge tube. The optical fiber holder (length of 6 cm with optical fiber mounted at its center) had to be filled by liquid nitrogen and thus the reactor wall temperature around (3 cm) the observation point was kept at 300 K or 77 K. The dependencies of relative intensities of the bands on decay time were given. Also the relative populations of N2 (B), N2 (C), N2+ (B) states were calculated and its dependencies on decay time and on argon concentration were given.

nitrogen post-discharge, nitrogen-argon mixture, kinetic processes

MAZÁNKOVÁ, V.; KRČMA, F.

2009

7. 9. 2009

FEKT VUT

Brno

978-80-214-3793-7

Proceedings of XVIIIth Symposium on Physics of Switching Arc

250

253

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