Effect of Burst Mode on Electron Density and Temperature in a Continuous Flowing Gas-Liquid Nonthermal Plasma Reactor

We build upon previous work to examine how the delivery mode of nanosecond pulses influences electron density, electron temperature and gas temperature using time-averaged optical emission spectroscopy (OES) in a nonthermal plasma gas-liquid flow reactor with argon and deionized liquid water. The electron density was estimated using the full width half maximum (FWHM) of at 656.28nm. The gas temperature and electron temperature were estimated using two temperature fitting of OH (A-X) band at 310nm and line intensity ratio method for Ar lines respectively. A custom-made power supply (Airity Technologies, LLC) was used to vary three burst mode parameters: inner burst frequency (the time between the bursts), burst period (1 over the time between the pulses in the burst), and N-cycles (number of pulses in a burst). The inner burst frequency was varied between 100kHz-1MHz, and the average electron density varied between 8×10¹⁵ cm^-3 – 1.6×10¹⁶ cm^-3, with the peak observed at 100kHz. The burst period was varied between 0.1ms-1ms, and the average electron density varied between 7×10¹⁵ cm^-3 – 8×10¹⁵ cm^-3, with the peak observed to be constant between 0.25ms-1ms. N-cycles were varied from 1-20 cycles, and the average electron density varied between 6×10¹⁵ cm^-3 – 1.8×10¹⁶ cm^-3, with the peak observed at 1 N-cycle.