Microwave Diagnostics of Cold Atmospheric Pressure Plasma Jets Based on the Radiation Pattern Measurements

This article solves the problem of determining the influence of an extended plasma jet on the radiation pattern of a short-grounded antenna in the frequency range of 1-3 GHz. The electron density and the electron collision frequency are set such that they correspond to atmospheric plasma jets of a barrier discharge in a helium flow. The problem of determining the radiation pattern is solved numerically using ANSYS HFSS and analytically using simple theoretical expressions for the field of a short antenna. The results using these two approaches are consistent with each other well. Based on the obtained results, a novel microwave diagnostic method for the atmospheric plasma jets was proposed.