Self-Consistent Microwave Propagation and Power Absorption in 1D Radial Fluid Models

A correct description of the power deposition in plasma systems is essential for accurately calculating the remaining quantities, yet traditional approaches often rely on simplified static profiles or experimental emission profiles, which incorrectly predict power deposition. To overcome this, the current study introduces a computational framework for coupling fluid models with a microwave propagation model in order to self-consistently calculate the absorbed power density.

The electric field model solves a modified Helmholtz equation on a 2D Cartesian plane using finite differences in the frequency domain, considering a quasi-steady state approximation. This approach eliminates the computational complexity of full Maxwell’s equation systems while retaining wave propagation and interaction with the electrons. The plasma model is radial and time-resolved, incorporating detailed nitrogen chemistry and transport phenomena. This framework is verified against simplified analytical solutions and validated against experimental emission intensity profiles and experimental temperature measurements from nitrogen discharges.

While the current implementation is on 1D radial geometry, the methods and coupling strategy are designed to be extensible to higher dimensions and more complex reactor configurations, including integration with CFD models.