Regulation of pulse DC power on the Long lived reactive species concentration of AC excited plasma in liquid phase

Plasma Activated Medium (PAM) can effectively inactivate bacteria and induce apoptosis and necrosis of cancer cells because of the presence of active particles. In order to explore the relationship between the particle concentration in PAM and the phase difference, power supply position and pulse width during dual power supply discharge. A device based on plasma jet and adds a metal ring to the outlet of the jet is designed. Experiments show that} H2 O2, H+ and NO3⁻ have the largest concentration in PAM when the needle is AC, the ring is DC pulse, the phase difference between dual power supply is 270°, and the pulse width is 1us. NO2⁻ is the largest concentration in PAM when the needle is DC pulsed, the ring is AC, the phase difference between the dual power supply is 90°-180°, and the pulse width is 1us. The possible causes of this phenomenon are analyzed. It is helpful to control the formation of plasma active components and is of great significance for practical application.