This article aims to understand the physics of pulsed plasmas by investigating the ionization and recombination of pulsed plasmas on the nanosecond timescale and how operating conditions affect the time-resolved electron temperature and electron density of a pulsed plasma. A nanosecond-pulsed argon plasma discharge was generated at various pulse frequencies, widths, and pressures. The argon emission lines were analyzed with a time-synchronized, intensified charge-coupled device (ICCD) spectrometer assembly that gated at 4 ns, and relative intensities of strong argon neutral and ion lines were used in line-ratio calculations. These experimentally determined ratios were compared to theoretical ratios generated from PrismSPECT, a collisional-radiative spectral analysis software, to obtain time-resolved electron temperature ( $\sim 1$ eV) and electron density ( $10^{14}-10^{15}$ cm $^{-3}$ ) over the various operating conditions as well as to discover trends of these plasma parameters over the lifetime of the pulsed plasma. Increasing pulse repetition frequency of the plasma increased the value of maximum $T_{e}$ , shortened the $T_{e}$ rise and decay times, and increased the excited argon neutral population. While $n_{e}$ was relatively independent of pulse frequency, higher pulse frequencies resulted in a faster $n_{e}$ decay. Maximum $T_{e}$ and $n_{e}$ were weakly dependent on applied discharge voltage, but both parameters decayed sooner in time with increasing voltage. Lastly, $T_{e}$ was inversely proportional to pressure, but $n_{e}$ was approximately linear. All three pressures had similar but time-shifted temporal profiles for $n_{e}$ . Plasmas in all operating conditions had ionization and recombination times in the tens of nanoseconds.

中文翻译：

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纳秒脉冲氩等离子体等离子体参数的时间分辨测量

本文旨在通过研究脉冲等离子体在纳秒时间尺度上的电离和复合以及操作条件如何影响脉冲等离子体的时间分辨电子温度和电子密度，来了解脉冲等离子体的物理特性。在各种脉冲频率、宽度和压力下产生纳秒脉冲氩等离子体放电。使用时间同步的增强型电荷耦合器件 (ICCD) 光谱仪组件分析氩发射线，其门控时间为 4 ns，强氩中性线和离子线的相对强度用于线比计算。将这些实验确定的比率与 PrismSPECT（一种碰撞辐射光谱分析软件）生成的理论比率进行比较，以获得时间分辨的电子温度（ $\sim 1$ eV) 和电子密度 ( $10^{14}-10^{15}$ 厘米 $^{-3}$ ) 在各种操作条件下，以及发现这些等离子体参数在脉冲等离子体的寿命期间的趋势。增加等离子体的脉冲重复频率增加了最大值 $T_{e}$ ，缩短了 $T_{e}$ 上升和衰减时间，并增加了激发的氩中性种群。尽管 $n_{e}$ 相对独立于脉冲频率，较高的脉冲频率导致更快的 $n_{e}$ 衰变。最大 $T_{e}$ 和 $n_{e}$ 微弱地依赖于施加的放电电压，但随着电压的增加，这两个参数衰减得更快。最后， $T_{e}$ 与压力成反比，但 $n_{e}$ 近似线性。所有三种压力都具有相似但随时间变化的时间分布 $n_{e}$ . 在所有操作条件下，等离子体的电离和复合时间都在几十纳秒内。