Curling probe measurement in plasma

Abstract

The curling probe is one of the active resonance absorption spectroscopic methods, the methods utilized the probe reflection coefficient spectrum to determine the plasma density. The proposed model of the curling probe uses the deviation of the most matched frequency, the frequency in which the minimum reflection coefficient occurs, when the probe is submerged in different mediums. The probe structure is simple and claimed to be robust and efficient. The experiments of a curling probe were performed and the simulations for the probe reflection coefficient for both previously reported probe and the constructed probe configuration have been conducted. The previously reported model could not describe our experimental and simulated results. However, our simulation and experiments conformed and indicated that the most matched frequency did not respond to the change of plasma density.