TITLE

Properties of microwave plasma torch operating at a low pressure

AUTHOR(S)
Cho, Soon C.; Uhm, Han S.; Hong, Yong C.; Kim, Jae H.
PUB. DATE
October 2008
SOURCE
Physics of Plasmas;Oct2008, Vol. 15 Issue 10, p103503
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
A microwave plasma torch system is attached to a low-pressure chamber in this study. The electric field induced in a quartz discharge tube by microwave radiation breaks down the gas at a sufficiently low pressure, igniting the plasma, which is continuously sustained by the microwave radiation. The plasma profile at a very low pressure is shown to be asymmetric with higher density on the incoming side of the microwaves. The gas temperature at the bright spot of the torch plasma measured via the optical emission from hydroxide radicals is shown to increase drastically upon high-pressure operation as the microwave power increases. The electron density at the torch flame is measured by recording the Stark broadening of the hydrogen Balmer beta line. The plasma density increases as the microwave power increases. The typical argon plasma density of a plasma torch powered at 500 W under a pressure of 150 Torr is on the order of 1014/cm3. The electron temperature in the argon torch plasma was estimated to be 1.5 eV, thereby effectively exciting the molecules in the torch gas. Disintegration of nitrogen fluoride (NF3) indicates that a microwave plasma torch operating at a low pressure can efficiently generate an abundant amount of chemical radicals.
ACCESSION #
35103348

 

Related Articles

  • Ozone-stimulated emission due to atomic oxygen population inversions in an argon microwave plasma torch. Lukina, N.; Sergeichev, K. // Plasma Physics Reports;Jun2008, Vol. 34 Issue 6, p519 

    It is shown that, in a microwave torch discharge in an argon jet injected into an oxygen atmosphere at normal pressure, quasi-resonant energy transfer from metastable argon atoms to molecules of oxygen and ozone generated in the torch shell and, then, to oxygen atoms produced via the...

  • Large internal quantum efficiency of In-free UV-emitting GaN/AlGaN quantum-well structures. Fuhrmann, D.; Retzlaff, T.; Rossow, U.; Bremers, H.; Hangleiter, A.; Ade, G.; Hinze, P. // Applied Physics Letters;5/8/2006, Vol. 88 Issue 19, p191108 

    We have achieved dramatic improvement of the internal quantum efficiency (IQE) for ultraviolet-emitting GaN/AlGaN quantum-well (QW) structures. Despite a defect density of a few 109 cm-2 and the use of an In-free QW we achieve best values for the IQE at room temperature of 26%. Under strong...

  • Powerful terahertz emission from laser wake fields excited in inhomogeneous plasmas. Zheng-Ming Sheng; Kunioki Mima; Zhang, Jie // Physics of Plasmas;Dec2005, Vol. 12 Issue 12, p123103 

    Powerful coherent emission of broadband few-terahertz radiation can be produced from a laser wake field by linear mode conversion. This occurs when the laser pulse is incident obliquely to the density gradient of inhomogeneous plasmas. The emission spectrum and conversion efficiency predicted by...

  • Study of the optical properties of a pulse-periodic high-pressure cesium discharge. Baksht, F.; Gavrish, S.; Kaplan, V.; Lapshin, V.; Martsinovsky, A. // Plasma Physics Reports;Dec2010, Vol. 36 Issue 13, p1199 

    Results of theoretical and experimental studies of the optical spectrum of a pulse-periodic high-pressure cesium discharge are presented. The results of calculations are in good agreement with experimental data. The possibility of creating an efficient light source based on recombination...

  • Diurnal temperature range over Europe between 1950 and 2005. Makowski, K.; Wild, M.; Ohmura, A. // Atmospheric Chemistry & Physics;2008, Vol. 8 Issue 21, p6483 

    It has been widely accepted that diurnal temperature range (DTR) decreased on a global scale during the second half of the twentieth century. Here we show however, that the long-term trend of annual DTR has reversed from a decrease to an increase during the 1970s in Western Europe and during the...

  • Effect of Direct Radiative Forcing of Asian Dust on the Meteorological Fields in East Asia during an Asian Dust Event Period. Ahn, Hyun-Ju; Park, Soon-Ung; Chang, Lim-Seok // Journal of Applied Meteorology & Climatology;Oct2007, Vol. 46 Issue 10, p1655 

    Coupled and noncoupled models in a grid of 60 × 60 km2 in the eastern Asian domain have been employed to examine the effect of the direct radiative forcing of the Asian dust aerosol on meteorological fields for an intense Asian dust event observed in eastern Asia on 18–23 March 2002....

  • Absorption of CO[sub 2] laser emission by freon-12. Al-Hawat, S.; Saloum, S.; Zidan, M. D. // Applied Physics B: Lasers & Optics;Feb2004, Vol. 78 Issue 3/4, p439 

    The infrared (IR) absorption of freon-12 (CF[sub 2]Cl[sub 2]) was studied in the emission range of a 3-W tunable CW CO[sub 2] laser by using a brass cell with KBr windows that was located outside the laser resonator. The results show that CF[sub 2]Cl[sub 2] absorbs all CO[sub 2] laser emission...

  • Exploring Black Hole Accretion in Active Galactic Nuclei with Simbol-X. Goosmann, R. W.; Dovcˇiak, M.; Mouchet, M.; Czerny, B.; Karas, V.; Gonçalves, A. // AIP Conference Proceedings;5/11/2009, Vol. 1126 Issue 1, p162 

    A major goal of the Simbol-X mission is to improve our knowledge about black hole accretion. By opening up the X-ray window above 10 keV with unprecedented sensitivity and resolution we obtain new constraints on the X-ray spectral and variability properties of active galactic nuclei. To...

  • Three-halves harmonic emission from two-color experiments. Young, P. E.; Baldis, H. A.; Remington, B. A.; Estabrook, K. G. // Physics of Fluids B: Plasma Physics;Jun90, Vol. 2 Issue 6, p1228 

    Three-halves harmonic emission from a plasma in which the peak plasma density is n[sub c] > n > n[sub c]/4 has been temporally and spectrally resolved. This is achieved by using 0.53 μm wavelength laser light to irradiate a plasma preformed by 0.35 μm wavelength laser light. It is observed...

Share

Read the Article

Courtesy of THE LIBRARY OF VIRGINIA

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics