Measurement of metastable He{sup *}(2{sup 3}S{sub 1}) density in dielectric barrier discharges with two different configurations operating at around atmospheric pressure
- Department of Electronic Science and Engineering, Kyoto University, Kyoto-Daigaku Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan)
We have measured the density of metastable He atoms in the lowest triplet state (2{sup 3}S{sub 1}) with a diode-laser absorption spectroscopic technique in atmospheric pressure plasmas produced by dielectric barrier discharge schemes. Two different types of electrode configuration are employed: one is a conventional parallel-plate system and the other is a microdischarge integrated system with stacked metal-mesh electrodes covered by insulating films. We have analyzed the pressure-broadened spectral line corresponding to the 2{sup 3}S{sub 1}{yields}2{sup 3}P{sub J} (J=0-2) transition to derive the broadening coefficient and to calibrate absolute densities. The measured density ranges from 10{sup 11} to 10{sup 12} cm{sup -3}, but the values in the mesh-type system are larger than those in the parallel-plate system by about one order of magnitude. The density, however, depends strongly on the gas flow rate, showing the influence of quenching by the Penning-ionization process with impurities. Those behaviors are consistent with the variation of the electron density estimated by millimeter-wave transmittance measurement.
- OSTI ID:
- 20711739
- Journal Information:
- Journal of Applied Physics, Vol. 97, Issue 12; Other Information: DOI: 10.1063/1.1922581; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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