Parametric study of atmospheric pressure microwave-induced Ar/O{sub 2} plasmas and the ambient air effect on the plasma
- Department of Physics, Korea Advanced Institute of Science and Technology, 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)
A torch type microwave-induced afterglow plasma was produced at atmospheric pressure using an open-ended fused silica concentric double tube assisted by Ar and O{sub 2} supply gases. The plasma emerged from the end of the discharge tube and was exposed to ambient air. A parametric study of the plasma characteristics was performed by measuring the temperature, density, and plasma volume as the operational parameters such as microwave power, gas flow rate, and its composition were varied. The excitation temperature (T{sub exc}) obtained from the Ar I emission spectrum ranged from 3010 to 4350 K and the rotational temperature (T{sub rot}) measured from the OH and O{sub 2} diatomic molecular spectra ranged from 2250 to 3550 K. The electron density (n{sub e}) from the H{sub {beta}} Stark broadening width at the plasma core was in the range of 6.6 to 7.6x10{sup 14} cm{sup -3}. The two-dimensional distribution of T{sub exc} and T{sub rot} was also obtained. Experiments while varying the Ar and O{sub 2} gas flow rate and the O{sub 2}/Ar ratio showed that n{sub e} was reduced but T{sub exc} was increased as the O{sub 2} flow rate was increased. Using an additional dielectric tube for shielding the plasma from the ambient air demonstrated a significantly enlarged plasma length and lower T{sub rot} due to the nitrogen entrainment, as compared to the unshielded case.
- OSTI ID:
- 20860329
- Journal Information:
- Physics of Plasmas, Vol. 13, Issue 10; Other Information: DOI: 10.1063/1.2357722; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 1070-664X
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
AFTERGLOW
ARGON
ATMOSPHERIC PRESSURE
DIELECTRIC MATERIALS
ELECTRON DENSITY
ELECTRON TEMPERATURE
EMISSION SPECTRA
EXCITATION
FLOW RATE
GAS FLOW
HIGH-FREQUENCY DISCHARGES
ION TEMPERATURE
LINE BROADENING
MICROWAVE RADIATION
NITROGEN
OXYGEN
PARAMETRIC ANALYSIS
PLASMA
PLASMA DENSITY
SILICA
STARK EFFECT
TUBES