9:30 AM - 9:45 AM
[15a-2V-3] Measurement of N2 Rotational Temperature Distribution in Atmospheric Positive DC Glow Corona by Spectroscopic Imaging
Keywords:spectroscopic Imaging,glow corona discharge,gas temperature distribution
Spectroscopic method which gives no disturbance to the measuring object has been used as a reliable diagnostic technique for non-thermal plasma. However, plasma parameter measured by spectroscopic method is only a spatially averaged data in a photometric point. Therefore, revealing a spatial distribution of plasma parameter still remains an open research problem.
An experimental method of determining a two-dimensional (2D) image of the N2 rotational temperature in stationary atmospheric non-thermal plasma by spectroscopic imaging was presented. In the experiment, a steady-state glow corona discharge was generated by applying a positive DC voltage to a rod-plane electrode in synthetic air (N2: 79%, O2: 21%). The diameter of rod electrode was 4 mm. A quartz glass having a conductive ITO-coated front-surface was used as a transparent plane electrode. The thickness of the ITO coat and the quartz glass was 15-20 nm and 1 mm, respectively. The ITO coating is thin enough for (0-2) band light emission spectrum of N2 second positive system to penetrate. The transmission rate in the vicinity of N2 second positive system band (0-2) is approximately 82%. The surface-coated quartz glass was sandwiched between two plates of stainless having a hole (100 mm in diameter). The stainless plates and the ITO-coated surface of the quartz glass were electrically grounded. The rod electrode with a hemispherical tip was vertically set above the center of the quartz glass front-surface with 15 mm. Spectral images of a positive DC glow corona were taken using a gated Intensified Charge-Coupled Device (ICCD) camera with ultra narrow band-pass filters, corresponding to the head and tail of a N2 second positive system band (0-2). The qualitative N2 rotational temperature was obtained from the emission intensity ratio between the head and tail of the N2 second positive system band (0-2). The directions of observation were toward the lateral side and hemisphere side of the rod electrode.
The change in the distribution of rotational temperature in a positive DC glow discharge due to the amplitude of applied voltage was investigated. As a result, it was confirmed the rotational temperature distribution in a positive DC glow corona spread diffusely with increasing applied voltage. In particular, a distinctly high temperature region was formed in positive DC glow corona near the tip of the rod electrode just below the sparkover voltage.
An experimental method of determining a two-dimensional (2D) image of the N2 rotational temperature in stationary atmospheric non-thermal plasma by spectroscopic imaging was presented. In the experiment, a steady-state glow corona discharge was generated by applying a positive DC voltage to a rod-plane electrode in synthetic air (N2: 79%, O2: 21%). The diameter of rod electrode was 4 mm. A quartz glass having a conductive ITO-coated front-surface was used as a transparent plane electrode. The thickness of the ITO coat and the quartz glass was 15-20 nm and 1 mm, respectively. The ITO coating is thin enough for (0-2) band light emission spectrum of N2 second positive system to penetrate. The transmission rate in the vicinity of N2 second positive system band (0-2) is approximately 82%. The surface-coated quartz glass was sandwiched between two plates of stainless having a hole (100 mm in diameter). The stainless plates and the ITO-coated surface of the quartz glass were electrically grounded. The rod electrode with a hemispherical tip was vertically set above the center of the quartz glass front-surface with 15 mm. Spectral images of a positive DC glow corona were taken using a gated Intensified Charge-Coupled Device (ICCD) camera with ultra narrow band-pass filters, corresponding to the head and tail of a N2 second positive system band (0-2). The qualitative N2 rotational temperature was obtained from the emission intensity ratio between the head and tail of the N2 second positive system band (0-2). The directions of observation were toward the lateral side and hemisphere side of the rod electrode.
The change in the distribution of rotational temperature in a positive DC glow discharge due to the amplitude of applied voltage was investigated. As a result, it was confirmed the rotational temperature distribution in a positive DC glow corona spread diffusely with increasing applied voltage. In particular, a distinctly high temperature region was formed in positive DC glow corona near the tip of the rod electrode just below the sparkover voltage.