Abstract
The measurement of absolute densities of reactive species and radicals such as OH is of growing interest for many plasma applications. In this paper, we extend the use of a self-absorption model for atomic emission spectroscopy to molecular emission spectroscopy. The proposed analysis of self-absorbed molecular emission spectra is a simple and inexpensive method to determine OH(X) densities and rotational temperatures compared to laser induced fluorescence. We compare the recorded absolute OH density in a non-equilibrium diffuse atmospheric-pressure RF glow discharge by this method with broadband UV absorption considering a number of rotational lines with J′ 6.5, the detection limit of the line integrated OH(X) density with this method is of the order of 2 × 1019 m-2. The accuracy of the density is sensitive to the rotational temperature of the OH(A) state and the non-equilibrium rotational population distribution.
Original language | English (US) |
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Article number | 04LT02 |
Journal | Plasma Sources Science and Technology |
Volume | 25 |
Issue number | 4 |
DOIs | |
State | Published - Jul 13 2016 |
Bibliographical note
Publisher Copyright:© 2016 IOP Publishing Ltd.
Keywords
- absorption
- optical emission spectroscopy
- radical densities
- self-absorption