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Title: The production mechanisms of OH radicals in a pulsed direct current plasma jet

The production mechanism of OH radicals in a pulsed DC plasma jet is studied by a two-dimensional (2-D) plasma jet model and a one-dimensional (1-D) discharge model. For the plasma jet in the open air, electron-impact dissociation of H{sub 2}O, electron neutralization of H{sub 2}O{sup +}, as well as dissociation of H{sub 2}O by O(1D) are found to be the main reactions to generate the OH species. The contribution of the dissociation of H{sub 2}O by electron is more than the others. The additions of N{sub 2}, O{sub 2}, air, and H{sub 2}O into the working gas increase the OH density outside the tube slightly, which is attributed to more electrons produced by Penning ionization. On the other hand, the additions of O{sub 2} and H{sub 2}O into the working gas increase the OH density inside the tube substantially, which is attributed to the increased O (1D) and H{sub 2}O concentration, respectively. The gas flow will transport high density OH out of the tube during pulse off period. It is also shown that the plasma chemistry and reactivity can be effectively controlled by the pulse numbers. These results are supported by the laser induced fluorescence measurements and are relevant tomore » several applications of atmospheric-pressure plasmas in health care, medicine, and materials processing.« less
Authors:
; ; ;  [1] ;  [2] ;  [3]
  1. State Key Lab of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, WuHan, Hubei 430074 (China)
  2. Plasma Nanoscience, CSIRO Materials Science and Engineering, P. O. Box 218, Lindfield, New South Wales 2070 (Australia)
  3. (Australia)
Publication Date:
OSTI Identifier:
22303449
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physics of Plasmas; Journal Volume: 21; Journal Issue: 9; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
70 PLASMA PHYSICS AND FUSION TECHNOLOGY; ATMOSPHERIC PRESSURE; DIRECT CURRENT; ECOLOGICAL CONCENTRATION; ELECTRONS; GAS FLOW; HYDROXYL RADICALS; IONIZATION; LASERS; PLASMA JETS; PULSES; WATER