Pink Afterglow in Nitrogen-Argon Mixtures

conference paper

English

The effect of nitrogen pink afterglow was studied by optical emission spectroscopy in the DC flowing regime at total gas pressure of 700 Pa and discharge current of 120 mA. Discharge was created in Pyrex tube of 13 mm i.d. using nitrogen and argon of 99.999% purity with additional purification by Oxicler columns and liquid nitrogen traps. The part of 3 cm around the observation point had to be cooled down to liquid nitrogen wall temperature. The maximum of pink afterglow emission in pure nitrogen was observed at decay time of 6 ms and it was moved to the later decay times with the increasing argon percentage in the gas mixture. Simultaneously, the intensity of pink afterglow decreased and at the nitrogen-argon ratio of about 1:1 the effect disappeared. At the highest argon concentrations over 90 %, the visible light emission during the post-discharge was negligible. The other observed effect was the extension of an active discharge downstream the discharge tube with the increase of the argon presence in the gas mixture over about 50 %. Similar effects were observed when the discharge tube wall around the observation point was cooled down to liquid nitrogen temperature. The argon atomic lines were observed during the post-discharge at the highest argon concentration at low wall temperature, only. The kinetic model showed that the pink afterglow quenching was connected to the decrease of the v-v and pooling processes efficiency, the extension of the active discharge was done by energy transfer between argon metastables and nitrogen ground state molecules.

post-discharge, nitrogen afterglow, nirogen-argon mixture

KRČMA, F.; ŽÁKOVÁ, M.

2008

16. 6. 2008

AV ČR

Praha

978-80-01-04030-0

23rd Symposium on Plasma Physics and Technology - Book of Abstracts

104

104

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