OH radical production in an atmospheric pressure surface micro-discharge array. (17th October 2016)

• Record Type: Journal Article
• Authors: Li, D; Nikiforov, A; Britun, N; Snyders, R; Kong, M G; Leys, C
• Is Part Of: Journal of physics. Volume 49:Number 45(2016)
• Publication Date: 2016-10-17
• Subjects: surface discharge -- laser-induced fluorescence -- absorption spectroscopy -- hydroxyl radicals; Physics -- Periodicals; 530
• DOI: 10.1088/0022-3727/49/45/455202
• Languages: English
• ISSNs: 0022-3727

Abstract

Abstract: The generation of OH radicals from an array of surface micro-discharges working in atmospheric pressure He/Ar/H2 O mixtures is investigated. The absolute OH density and its temporal-and-spatial dynamics are detected by UV broadband absorption spectroscopy (UV-BAS) and laser-induced fluorescence (LIF) spectroscopy. The measured absolute density of OH( X ) state is about 10 21 m −3 in Ar/H2 O mixture reaching a peak at 0.05% of H2 O. In the case of He/H2 O mixtures however, the peaking at ~10 19 m −3 is approximately two orders of magnitude lower and decreases monotonously with increasing H2 O content. From a control standpoint, the ratio of the Ar/He mixture may be adjusted to tune the OH density over two orders of magnitude and to modulate the H2 O content dependence of the OH density. The capability of modulating the OH radical production over a large density range is of practical interest for many applications such as atmospheric chemistry and biochemistry. With the array of atmospheric micro-discharges sustained over a large electrode area, a uniform distribution of its OH density can be achieved in a plane parallel to the electrodes thus enabling spatially controlled surface treatment of large samples.