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      Permanent link:
      https://www.ias.ac.in/article/fulltext/pram/087/06/0086

    • Keywords

       

      Atmospheric pressure glow discharge; radiofrequency; excitation temperature; gas temperature.

    • Abstract

       

      The parameters of radio frequency helium discharge under atmospheric pressure were studied by electrical and optical measurements using high voltage probe, current probe and optical emission spectroscopy. Two discharge modes $\alpha$ and $\gamma$ were observed within certain limits. During $\alpha$ to $\gamma$ mode transition, a decrease in voltage (280–168 V), current (2.05–1.61 A) and phase angle (76$^{\rm o}-56^{\rm o}$) occurred. The discharge parameters such as resistance, reactance, sheath thickness, electron density, excitation temperature and gas temperature were assessed by electrical measurements using equivalent circuit model and optical emission spectroscopy. In $\alpha$ mode, the discharge current increased from 1.17 to 2.05 A, electron density increased from $0.19 \times 10^{12} {\rm to} 0.47 \times 10^{12} {\rm cm}^{−3}$ while sheath thickness decreased from 0.40 to 0.25 mm. The excitation temperatures in the $\alpha$ and $\gamma$ modes were 3266 and 4500 K respectively, evaluated by Boltzmann’s plot method. The estimated gas temperature increased from 335 K in the α mode to 485 K in the γ mode, suggesting that the radio frequency atmospheric pressure helium discharge can be used for surface treatment applications.

    • Author Affiliations

       

      SAFDAR HUSSAIN1 HAFIZ IMRAN AHMAD QAZI1 SHANAWER NIAZ1 MANZOOR AHMAD BADAR1

      1. Department of Physics, University of Sargodha, 40100 Sargodha, Pakistan
    • Dates

       
  • Pramana – Journal of Physics | News

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