Coplanar surface barrier discharge ignited in water vapor—a selective source of OH radicals proved by (TA)LIF measurement. (4th December 2017)

• Record Type: Journal Article
• Authors: Procházka, V; Tučeková, Z; Dvořák, P; Kováčik, D; Slavíček, P; Zahoranová, A; Voráč, J
• Is Part Of: Plasma sources science & technology. Volume 27:Number 1(2018:Feb.)
• Publication Date: 2017-12-04
• Subjects: laser-induced fluorescence -- TALIF -- hydroxyl -- OH -- dielectric barrier discharge -- DBD -- water vapor; 52.70.Kz -- 52.25.Ya -- 52.50.Dg; Plasma (Ionized gases) -- Periodicals; 530.44
• DOI: 10.1088/1361-6595/aa9ad4
• Languages: English
• ISSNs: 0963-0252

Abstract

Abstract: Coplanar dielectric barrier discharge (DBD) was ignited in pure water vapor at atmospheric pressure in order to generate highly oxidizing plasma with one specific type of reactive radicals. In order to prevent water condensation the used plasma reactor was heated to 120 ◦ C. The composition of the radical species in the discharge was studied by methods based on laser-induced fluorescence (LIF) and compared with analogous measurements realized in the same coplanar DBD ignited in air. Fast collisional processes and laser-surface interaction were taken into account during LIF data processing. It was found that coplanar DBD ignited in water vapor produces hydroxyl (OH) radicals with concentration in the order of 10 20 m −3, which is 10 × higher than the value measured in discharge in humid air (40% relative humidity at 21 ◦ C). The concentration of atomic hydrogen radicals in the DBD ignited in water vapor was below the detection limit, which proves that the generation of oxidizing plasma with dominance of one specific type of reactive radicals was achieved. The temporal evolution, spatial distribution, power dependence and rotational temperature of the OH radicals was determined in the DBD ignited in both water vapor and air.