Plasma Jet Array Driven by Nanosecond Pulses

Atmospheric pressure plasma jet (APPJ), the flexible way to generate plasma containing abundant high-energy electrons, ions, radicals and other active species in open space, is a promising tool in environmental protection, material surface treatment, and bio-medicine. However, APPJ’s weak ionization intensity and small treatment area have limited its efficiency. Plasma jet array has been considered as an effective method to improve efficiency and enlarge treatment area by grouping up several APPJs. Especially, the jet array excited by the nanosecond (ns) pulse shows merits of large treatment area and high chemical reactivity. However, the pulse parameters, electrode structures, active species addition seriously influence the discharge characteristics of the jet array. For the practical applications, it is important to obtain the rules of the discharge characteristics of jet array in different conditions and understand the related mechanisms. In this chapter, the downstream uniformity of the ns pulsed jet array is investigated by discharge image measurement, and the plasma reactivity is investigated by optical emission spectra measurement at different amplitudes of applied voltage, rising time and pulse repetition frequency (PRF), electrode configurations and precursor addition. The voltage-current waveform and Schlieren image are measured and the electrical field distribution of the jet array is simulated to reveal the interaction mechanisms and the discharge mode transition of jet array. The content of this chapter is of importance to understand the influence of the operation conditions and electrode configurations for the realization of controllable and scalable pulse excited jet array for various applications.