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Abstract The optical morphology of discharge is the main characteristic parameter describing the physical process of the discharge, and the luminescence behavior is inextricably linked to the motion behavior of charged particles. Since the Trichel discharge in air is a weak ionization event occurring on the sub‐nanosecond time scale, micron space scale and accompanied by weak luminescence, the current experimental observation means have a low spatial and temporal resolution, which is insufficient to study the details of its luminescence properties clearly. To address this problem, the intensity of light generated by Trichel discharge in air is first measured and resolved in time and space using a constructed ultrafast optical counting and imaging system. At a very high temporal resolution of 55 ps, it is found that both its light emission and current pulse showed a trend of first rapid growth and then slow decline on the time scale of tens of nanoseconds. Later, in order to further investigate the connection between the microscopic behavior of charged particles and photons, a two‐dimensional hydrodynamic simulation model with three components (electrons, positive ions, and negative ions) is developed and the current simulation results are in good agreement with the experimental results. The results show that the size of the ionization region and the interaction between particles in the discharge process are the main factors affecting the Trichel pulse and its photoemission. Electrons play a dominant role in photon generation during the rise time process, while it is the recombination process of positive and negative charges, which contributes the main photons during the fall time process. Finally, it is proposed that the expression of photon flux should be amended to include an additional term responsible for the photons generated due to recombination. The study helps to advance the understanding of the luminescence characteristics and the discharge mechanism of Trichel discharge. |
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