Global model for high power microwave breakdown at high pressure in air

Global models (GM) have proven a key tool for modeling low temperature plasmas for materials processing due to simplicity and speed. However, a GM requires specification of the electron energy distribution function (EEDF). The assumption of a Maxwellian EEDF leads to inaccurate power absorption and reaction rate coefficients and results in errors in plasma parameter prediction in high power microwave (HPM) driven discharges. In this work, a GM was developed with a pressure-independent enhanced EEDF and enhanced power absorption model to improve fidelity for modeling HPM breakdown, and extended to two decades in applied frequency. The GM is applied to HPM breakdown in air at high pressure and over a wide frequency range, and results compared well with PIC-MCC simulations as well as experimental data.