Modeling of a Nanosecond Pulsed Atmospheric Pressure Plasma on Water

Recently, there is a rapidly growing body of work studying plasma-based water treatment for applications within the medical, environmental, and agriculture sectors. Atmospheric pressure plasmas produced by high voltage pulses with 10’s of nanoseconds in duration are well suited for treatment of liquids 1 , 2 , 3 and surfaces. Modeling of nanosecond pulsed plasma is challenging due to plasma complexity, as well as different reaction time-scales; from nanoseconds to seconds. Moreover, the plasma is affected by sheath formation 4 and reactions of aqueous species with gas phase plasma species at the plasma/liquid interface 5 . We present a time-dependent global model to study the decay of various plasma species in helium carrier gas and obtain the trends with changing the pulse frequency and pulse duration. The model in conjunction of voltage measurements and OES diagnostics provide a useful tool for such analyses.