标题： 光致发射对常压下纳秒氦微放电的影响 显示英文标题

标题： The effect of photoemission on nanosecond helium microdischarges at atmospheric pressure

摘要： 在氦-氮混合气体中，通过基于粒子的第一性原理模拟研究了由纳秒高压脉冲激发的大气压微放电，该模拟包括通过追踪光子轨迹的真空紫外（VUV）共振辐射传输。 这些真空紫外光子在发射过程中频率重新分布被详细包含，由于它们能够从阴极表面诱导电子发射，因此显著改变了计算得到的放电特性。 以这种方式产生的电子增强了等离子体密度，并观察到瞬态电流脉冲幅度显著增加。 模拟允许计算氦原子在2$^1$P共振态的密度，以及等离子体中光子的密度和到达电极的共振真空紫外辐射的线形。 这些结果表明等离子体中存在显著的辐射捕获现象，并且发现光子逃逸时间长于激发脉冲的持续时间。 显示英文摘要

摘要： Atmospheric-pressure microdischarges excited by nanosecond high-voltage pulses are investigated in helium-nitrogen mixtures by first-principles particle-based simulations that include VUV resonance radiation transport via tracing photon trajectories. The VUV photons, of which the frequency redistribution in emission processes is included in some detail, are found to modify remarkably the computed discharge characteristics due to their ability to induce electron emission from the cathode surface. The electrons created this way enhance the plasma density and a significant increase of the transient current pulse amplitude is observed. The simulations allow the computation of the density of helium atoms in the 2$^1$P resonant state, as well as the density of photons in the plasma and the line shape of the resonant VUV radiation reaching the electrodes. These indicate the presence of significant radiation trapping in the plasma and photon escape times longer than the duration of the excitation pulses are found.