Determination of Spectroscopic Temperatures and Electron Density in Rotating Gliding Arc Discharge

The spectroscopic characteristics of rotating gliding arc (RGA) discharge, codriven by a magnetic field and tangential gas flow, have been investigated by optical emission spectroscopy. In argon gas, the electron density of the atmospheric RGA plasma was measured, while the vibrotatinoal temperatures were measured in nitrogen discharge. By simulating the spectral line profile determined by the joint effects of Lorentzian (Stark, van der Waals, and natural) and Gaussian (Doppler and instrumental) broadening, the electron density fluctuated in the range of 1.32×10¹⁵-4.56×10¹⁵ cm^-3 and 4.06×10¹⁵-5.74×10¹⁵ cm^-3 within the variation of argon flow rate and applied voltage, respectively. The rotational temperature in N₂ discharge was obtained by comparing the modeled optical emission spectrum with the experimental measurements. The vibrational temperature was derived from a Boltzmann plot by analyzing the spectral bands of the second positive system of N₂ (C³ Π_u → B³Π_g). The vibrational and rotational temperatures varied in the range of 0.1-0.13 eV and 0.42-0.44 eV, respectively, under the same operating condition, indicating that the RGA discharge is a nonequilibrium plasma. By analyzing the fundamental spectroscopic parameters of the discharge, a comprehensive understanding of RGA plasma was achieved, facilitating its application in practical industry processes.