In this article, the influences of outgassing and flashover on the performance of a novel multipacting cathode are numerically investigated by using particle in cell-Monte Carlo collision (PIC-MCC) method, including the conditions of weak, medium, and strong outgassing. The numerical results demonstrate that under the condition of weak outgassing (0.1 Torr), multipacting is hardly influenced by gas ionization. Multipacting dominates the entire physical process. Due to the further improved output current by additional electrons generated from ionization, the weak outgassing can help cathode performance enhancement. Under the condition of medium outgassing (1 Torr), gas ionization first boosts multipacting developing and then tends to suppress multipacting process. During the initial stage, multipacting dominates the entire physical process. When multipacting tends to saturate, gas ionization will dominate the whole physical process. The rapidly increased output current will finally decrease gap voltage and induce the diode breakdown. Under the condition of strong outgassing (1 atm), multipacting is suppressed by gas ionization from beginning to end. Gas ionization dominates the whole physical process all the time. The strong effect of ionization collision will finally induce streamer discharge and diode breakdown.

中文翻译：

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PIC-MCC气体介质及闪络对多重阴极运行影响的研究


本文利用粒子池蒙特卡罗碰撞（PIC-MCC）方法，数值研究了放气和闪络对新型多重阴极性能的影响，包括弱放气、中放气和强放气条件。数值结果表明，在弱除气（0.1 Torr）条件下，多重作用几乎不受气体电离的影响。多重作用主导着整个物理过程。由于电离产生的额外电子进一步提高了输出电流，微弱的脱气有助于阴极性能的增强。在中等放气（1 Torr）条件下，气体电离首先促进倍增过程的发展，然后趋于抑制倍增过程。在初始阶段，多重作用主导了整个物理过程。当多重作用趋于饱和时，气体电离将主导整个物理过程。快速增加的输出电流最终会降低间隙电压并导致二极管击穿。在强放气（1atm）的条件下，多重作用自始至终都被气体电离所抑制。气体电离始终主导整个物理过程。电离碰撞的强烈作用最终会引起流光放电和二极管击穿。