Power limitations of nanosecond high-voltage pulsers in atmospheric pressure discharges

Abstract

This work investigates the operational limitations of commercial nanosecond pulsers when driving atmospheric pressure discharges. We demonstrated how these limitations can lead to unstable and incorrect results in plasma parameter measurements. Through a combination of resistive loads and using atmospheric pressure plasma jets, we experimentally demonstrated that when the nanosecond pulser is pushed to its maximum performance limits (high voltage, high frequency, and long pulse width), it becomes power-limited, causing the output voltage to collapse. This power-limited state creates a feedback loop with the plasma, leading to frequent transitions between different discharge regimes (filament and glow). In our case, this instability is driven by small, 500 V oscillations in the applied voltage, and traditional measurement techniques relying on multi-shot averaging might become unreliable under these conditions. We demonstrated that tuning of nanosecond pulser parameters can significantly improve the stability and performance of the plasma discharge, which can be verified by long, consecutive-shot scanning.