Computational Study on the Parallel Double-Curling Probe for Multi-Site Electron Density Measurement in Low-Temperature Plasma

Plasma diagnostics, especially electron density measurements, have attracted much attention as it promotes an understanding of plasma and its applications. In this study, a parallel double-curling probe, which consists of two individual curling slot antennae and one microwave in-put/output port, is demonstrated for multisite electron density measurements using three-dimensional electromagnetic wave simulations. We verify its step-by-step operation, including the demonstration of a single curling probe, double-curling probe, and parallel double-curling probe. For the single curling probe, we introduce a curling probe operation, while for the double-curling probe, we verify the operation of two curling probes with a single microwave input/output port. With respect to the parallel double-curling probe, simulation results indicate that it can mea-sure the multi-site electron density above its individual curling-slot antenna. This study is applicable for the parallelization and multiplication of curling probes in the development of plasma uniformity sensors.