Modeling characterisation of a bipolar pulsed discharge

TL;DR

This paper uses particle-based kinetic simulations to analyze the spatio-temporal characteristics of bipolar pulsed gas discharges at low pressure, focusing on ion flux and energy relevant for surface processing applications.

Contribution

It introduces detailed kinetic simulation analysis of bipolar pulsed discharges, highlighting their temporal evolution and ion characteristics for surface treatment.

Findings

Ion flux and energy vary with pulse parameters

Discharge characteristics depend on pressure and electrode gap

Potential and electric field distributions are mapped over time

Abstract

We apply particle based kinetic simulations to explore the characteristics of a low-pressure gas discharge driven by high-voltage ( $\sim$ kV) pulses with alternating polarity, with a duty cycle of $\approx$ 1% and a repetition rate of 5 kHz. The computations allow tracing the spatio-temporal development of several discharge characteristics, the potential and electric field distributions, charged particle densities and fluxes, the mean ion energy at the electrode surfaces, etc. As such discharges have important surface processing applications, e.g. in the treatment of artificial bones, we analyse the time-dependence of the flux and the mean energy of the ions reaching the electrode surfaces, which can be both conducting and dielectric. Our investigations are conducted for argon buffer gas in the 40-140 Pa pressure range, for 1-5 cm electrode gaps and voltage pulse amplitudes ranging between 600 V and 1200 V.