Research on three-dimensional streamer discharge light intensity distribution inversion of 1m rod-plate air gap

By utilizing discharge image information, various micro-parameters can be accurately measured. And images are usually 2D planar features of three-dimensional (3D) discharge, so it is necessary to conduct research on the inversion of 3D spatial characteristic parameters of discharge. The Intensified Charge Coupled Device (ICCD) discharge intensity image with a nanosecond exposure can reflect the instantaneous ionization process during discharge, but there is few research on 3D inversion based on ICCD discharge images. Therefore, based on the 1m rod-plate gap discharge test platform under positive lightning impulse, the study on the shooting of streamer discharge intensity images with nanosecond exposure and the inversion of 3D spatial intensity distribution was conducted. The inversion theory and the differences between different inversion algorithms were analysis. Given by the symmetry of the discharge gap structure and discharge light intensity images, a 3D spatial discharge light intensity distribution calculation method based on the Abel inverse transform principle was proposed. The research results indicate that the calculation results using the Hankel-Fourier transform method have the highest accuracy compared to other algorithms. And the spatial distribution of 3D light intensity is mainly more concentrated near the longitudinal central axis of the rod-plate gap. It is reasonable to ignore the space charge and related effects generated by ionization at a distance from the longitudinal central axis of the rod-plate gap during meter-level streamer discharge.