Intense plasma emissions by plasma direct jet-to-jet coupling in atmospheric pressure plasma jet arrays

Abstract

Summary form only given. We report the intense plasma emission by plasma direct jet-to-jet coupling in the plasma jet arrays created with honeycomb structured quartz tubes. The shape of the plasma jet array device is a honeycomb structure; one quartz tube is in the center of the array and the outer six tubes surround the centered tube. The copper tape, a powered electrode, is wrapped around each quartz tube and an indium tin oxide (ITO) glass, a ground electrode, is placed 10 mm from the ends of the quartz tubes with the glass side facing the plasma jets. Though the plasma jets are shown to be produced in all quartz tubes, the outer tubes which surrounded the centered quartz tube do not produce strong individual plumes but reinforce the centered plasma plume despite an equally distributed gas flow at a certain condition. We also confirmed through direct observation a much more incandescent plasma jet at the center tube of the array than a single atmospheric plasma jet. At identical conditions of applied voltage and linear velocity of the helium gas condition, the optical intensity from the centered plasma jet of the plasma jet array with seven tubes was approximately four times larger than a single plasma jet. Thusly, the stronger and concentrated plasma jet is due to the plasma direct jet-to-jet coupling. Besides the plasma array with honeycomb structured nineteen tubes was investigated to extend the conceptual idea of the intense plasma jet. The results show not only is there a great increase in the amplitude of the produced plasma emission with a large array size, but the large arrays produce higher plasma emissions at the negative peak of the input voltage. This higher emission is indicative of both a greater maximum intensity and an improved average discharge rate. This plasma concentrated behavior necessitates that diverse applications require strong discharge processes involving many charged particle transports and chemical plasma reactions using elementary structures and equipment.