C. Hibert et al., [OH(X)] measurements by resonant absorption spectroscopy in a pulsed dielectric barrier discharge, J APPL PHYS, 85(10), 1999, pp. 7070-7075
Good understanding of the different phases of the plasma-chemistry involved
is essential for the development of nonthermal plasma technologies for pol
lution control. These techniques are often based on the dissociation of par
ent gases to produce radicals that, in turn, decompose the toxic compounds.
Our research concerns OH radical production in a pulsed dielectric barrier
discharge (DBD). OH[A (2)Sigma - X (2)Pi(0,0)] emission in argon-watervapo
r gas mixtures has been studied. Particular attention has been paid to the
influence of water vapor partial pressure on the lifetime and intensity of
emitted fluorescence in order to develop a pulsed DBD ultraviolet light sou
rce for spectroscopic investigation. This source was used to perform OH(X (
2)Pi) time-resolved average absolute density measurements in other DBD disc
harges based on resonant absorption spectroscopy. This diagnostic has been
validated in argon and air-water vapor mixtures. The temporal behavior of t
he density OH(X (2)Pi) radicals after a pulse discharge has been studied in
argon and air with and without 500 ppm of trichloroethylene. This simple a
nd inexpensive tool, compared to more sophisticated laser absorption or las
er-induced fluorescence measurements for plasma investigation, is very usef
ul for characterizing the OH radical potential for pollutant oxidation. (C)
1999 American Institute of Physics. [S0021-8979(99)03110-2].