The diffusion effect of transverse magnetic field on filamentary atmospheric pressure glow discharge sustained by a resonant power supply

Abstract

Summary form only given. In our previous study, stable and long-interelectrode gap and large-volume atmospheric pressure glow discharge (APGD) in ambient air has been obtained by using a resonant power supply which can successfully and effectively restrict the development of glow to arc transition. However, the APGD is centimeter-level in the length but only several millimeters in diameter, the energy in the discharge channel is very concentrated, which does not benefit industrial applications. The purpose of this study is to make the plasma channel of the stable but filamentary APGD more diffusive by using a transverse magnetic field. In experiment, the transverse magnetic field which was produced by using the dc power supply electromagnet was perpendicular to the plasma channel. The resonant frequency of discharge power supply can adjust from 10 kHz to 60 kHz. By keeping the distance of interelectrode gap, and input voltage amplitude and frequency of resonant power supply constant, with the increase of the current of electromagnet, the discharge channel did not change in the inceptive certain range, which showed that the diffusion effect was not apparent when the magnetic field intensity was weak. When the current of electromagnet increased to a certain value and the transverse magnetic field was strong enough, the diameter of discharge channel gradually increased and the bright area, which was focused near the channel center before, becomed more uniform. Therefore, the diffusion effect of transverse magnetic field on filamentary APGD obtained by resonant power supply presented to be very effective. When the current of the electromagnet was fixed to a value which was efficient enough to diffuse the discharge channel apparently, then the resonant frequency was adjusted from 10kHz to 60 kHz. With the increase of the resonant frequency, the plasma channel diffuses obviously. Accordingly, a transverse magnetic field can enhance the diffusion effect of resonant frequency on plasma channel. It is very meaningful to study how to obtain stable and long-interelectrode gap and largevolume and uniform APGD by matching up the transverse magnetic and resonant power supply.