Argon metastable dynamics and lifetimes in a direct current microdischarge
| Autor: | Ilija Stefanovic, Sandra Schröter, T Kuschel, Marc Böke |
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| Rok vydání: | 2014 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 116:113302 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.4895714 |
| Popis: | In this paper we study the properties of a pulsed dc microdischarge with the continuous flow of argon. Argon metastable lifetimes are measured by tunable diode laser absorption spectroscopy (TDLAS) and are compared with calculated values which yield information about excitation and de-excitation processes. By increasing the gas flow-rate about 5 times from 10 to 50 sccm, the Arm lifetime increases from 1 to 5 μs due to the reduction of metastable quenching with gas impurities. Optical emission spectroscopy reveals nitrogen and water molecules as the main gas impurities. The estimated N2 density [N2] = 0.1% is too low to explain the measured metastable lifetimes. Water impurity was found to be the main de-excitation source of argon metastable atoms due to high quenching coefficients. The water impurity level of [H2O] = 0.15% to 1% is sufficient to bring calculated metastable lifetimes in line with experiments. The maximum value of water content in the discharge compared to the argon atoms is estimated to a... |
| Databáze: | OpenAIRE |
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