3D-tomographic reconstruction of gliding arc plasma

Abstract

This study presents three-dimensional (3D) emission tomography on gliding arc discharge for volumetric measurements of plasma luminosity fields. The 3D tomography of the plasma luminosity field enables quantification and characterization of 3D plasma features, which are not easily accessible in two-dimensional measurements. Simultaneous projections of the plasma discharge were imaged using multiple CMOS cameras, and an in-house developed tomographic method was used for the 3D reconstruction of the luminosity fields. Results show good field reconstruction quality and expected gliding arc topologies. Comparisons between arc 3D length and 2D projected length displayed that 2D measurements underestimated length by around 15% at the highest tested flow case. The mean 3D length initially increased with increasing air flow, while later decreasing at even higher flows. The standard deviation of 3D length increased with increasing flow. Arc curvature and overlap were generally seen to increase with higher flows in contrast to arc volume that was seen to decrease with increasing flow rates. This study aims to facilitate instantaneous 3D tomographic measurements of plasma luminosity fields to provide a detailed quantification of 3D characteristics and correlations of typical plasma features, thereby providing paths to remove line-of-sight effects and compensate for loss of information that may occur during two-dimensional measurements. The presented technique is applicable not only to gliding arcs but also to various other plasma systems.