File(s) under permanent embargo
Reason: This item is currently closed access.
Optical emission spectroscopy as a diagnostic for plasmas in liquids: opportunities and pitfalls
journal contribution
posted on 2010-06-23, 12:51 authored by Peter Bruggeman, Tiny Verreycken, Manuel A. Gonzalez, James L. Walsh, Michael G. Kong, Christophe Leys, Daan C. SchramIn this contribution, optical emission spectroscopy is evaluated and thoroughly analysed as a
diagnostic to characterize plasmas in and in contact with liquids. One of the specific properties
of plasmas in and in contact with liquids is the strong emission of OH(A–X) and of hydrogen
lines. As an example a 600 ns pulsed dc excited discharge in Ar, He and O2 bubbles in water is
investigated by time resolved optical emission spectroscopy. It is shown that the production
processes of excited species and the plasma kinetics strongly influence the emission spectrum.
This complicates the interpretation of the spectra but provides the opportunity to derive
production mechanisms from the time resolved emission. The importance of recombination
processes compared with direct electron excitation processes in the production of excited
states of the water fragments in plasmas with high electron densities is shown. The OH(A–X)
emission spectrum illustrates that even in these highly collisional atmospheric pressure
discharges the rotational population distribution deviates from equilibrium. A two-temperature
fit of the OH rotational population distribution leads to realistic gas temperatures for the
temperature parameter corresponding to small rotational numbers. The Hα and Hβ lines are
fitted with two component profiles corresponding to two different electron densities.
The obtained electron density is in the range 1021–1023 m−3. Possible complications in the
interpretation of obtained temperatures and electron densities are discussed.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Citation
BRUGGEMAN, P. et al., 2010. Optical emission spectroscopy as a diagnostic for plasmas in liquids: opportunities and pitfalls. Journal of Physics D: Applied physics, 43(124005), 8pp.Publisher
© Institute of Physics PublishingVersion
- NA (Not Applicable or Unknown)
Publication date
2010Notes
This article is Restricted Access. It was published in the journal, Journal of Physics D: Applied Physics [© Institute of Physics Publishing]. The definitive version is available at: http://iopscience.iop.org/0022-3727/43/12/124005/ISSN
0022-3727Language
- en