A large gap uniform discharge excited by a direct-current voltage at atmospheric pressure

摘要

Using a needle anode and a plate cathode, a large gap uniform discharge (up to 5?cm) is ignited under a low sustaining voltage by a coaxial dielectric barrier discharge in ambient air with argon used as working gas. Besides a plasma column near the anode, a dark space, and a cathode glow, a plasma plume can also be discerned. By spatial resolved measurement of the light emission from the discharge, it is found that the plasma column is a continuous discharge, while the plasma plume behaves like a “plasma bullet,” which travels from the cathode to the plasma column.