Nanosecond pulsed plasma

known for its low energy consumption and large volume

holds great potential for wastewater treatment. We designed a miniature needle water cathode discharge structure based on printed circuit board technology to achieve efficient plasma generation

investigated the development process of plasma under nanosecond pulses

and analyzed the effects of pulse parameters on plasma volume and luminous intensity. In short gap needle water cathode configurations

the initial tens of nanoseconds of the pulse play a decisive role in luminous intensity and volume

and secondary streamers can initially span the entire gas gap. Plasma volume and intensity increase with pulse width until saturation. Higher voltage amplitudes and shorter rise times result in greater plasma intensity and volume. When the repetition frequency exceeds 1 kHz

residual metastable molecules transfer energy to electrons via superelastic collisions

reducing the discharge threshold and significantly enhancing plasma volume and intensity. Additionally

we investigated the discharge characteristics of multi-needle configurations

achieving large-volume plasma generation through array electrodes.