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.

中文翻译：

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皮秒时间分辨率空气中特里切尔放电发光特性实验与模拟研究

放电的光学形貌是描述放电物理过程的主要特征参数，发光行为与带电粒子的运动行为有着千丝万缕的联系。由于空气中的特里切尔放电是发生在亚纳秒时间尺度、微米空间尺度并伴有微弱发光的弱电离事件，目前的实验观测手段时空分辨率较低，不足以研究其细节。其发光特性清晰。为了解决这个问题，首先使用构建的超快光学计数和成像系统在时间和空间上测量和解析空气中特里切尔放电产生的光强度。在 55 ps 的极高时间分辨率下，发现其发光和电流脉冲在数十纳秒的时间尺度上均呈现出先快速增长后缓慢下降的趋势。随后，为了进一步研究带电粒子与光子微观行为之间的联系，建立了电子、正离子、负离子三分量的二维流体动力学模拟模型，与目前的模拟结果吻合较好与实验结果。结果表明，电离区域的大小以及放电过程中粒子间的相互作用是影响Trichel脉冲及其光电发射的主要因素。上升时间过程中电子在光子产生中起主导作用，同时也是正负电荷的复合过程，它在下降时间过程中贡献主要光子。最后，建议对光子通量的表达进行修改，以包含一个额外的术语，负责因复合而产生的光子。该研究有助于推进对Trichel放电的发光特性和放电机制的理解。