We investigated flowing N 2 DC discharges both experimentally and theoretically. The discharge gas and N 2 (X 1 Σ + g ) vibrational temperatures, electron density ( n e ), reduced electric field (E/N), and radiative state densities were measured by optical emission spectrometry (OES) and Langmuir double probes. We formulated a discharge kinetic numerical model to calculate the densities of nitrogen species as functions of the gas residence time. We combine the experimental parameters measured in the discharge with the kinetic model to analyze different discharge conditions where E/N varies significantly. First, we analyzed the measured and calculated radiative states densities and N 2 (X 1 Σ + g ) vibrational distributions at the end of the positive column. Results show good agreement between calculated and measured parameters. Then, we studied the excited molecular species densities, and neutral and excited atoms densities as functions of the discharge gas residence time. This work presents for the first time the temporal densities of excited molecular and atomic states from 10 −9 to 10 −1 s discharge residence times, calculated for experimental conditions where n e presents a low variation and E/N varies from high (94 Td) to relatively low values (48 Td). The discharge experimental conditions are discharge current of 60 mA, gas pressure of 230–530 Pa, and gas flow rate of 0.9 Slm −1 .

中文翻译：

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流动 N2 直流放电正列中的中性和激发分子和原子密度

我们通过实验和理论研究了流动的 N 2 直流放电。放电气体和 N 2 (X 1 Σ + g ) 振动温度、电子密度 (ne)、还原电场 (E/N) 和辐射态密度通过光发射光谱法 (OES) 和朗缪尔双探针测量。我们制定了一个放电动力学数值模型来计算作为气体停留时间函数的氮物质密度。我们将放电中测量的实验参数与动力学模型相结合，以分析 E/N 变化显着的不同放电条件。首先，我们分析了测量和计算的辐射态密度和正极柱末端的 N 2 (X 1 Σ + g ) 振动分布。结果显示计算参数和测量参数之间具有良好的一致性。然后，我们研究了作为放电气体停留时间函数的激发态分子密度以及中性和激发态原子密度。这项工作首次提出了从 10 -9 到 10 -1 s 放电停留时间的激发态分子和原子态的时间密度，计算是在 ne 呈现低变化且 E/N 从高 (94 Td) 变化的实验条件下进行的到相对较低的值 (48 Td)。放电实验条件为放电电流为60 mA，气压为230-530 Pa，气体流速为0.9 Slm -1 。在 ne 呈现低变化且 E/N 从高 (94 Td) 到相对低值 (48 Td) 的实验条件下计算的。放电实验条件为放电电流为60 mA，气压为230-530 Pa，气体流速为0.9 Slm -1 。在 ne 呈现低变化且 E/N 从高 (94 Td) 到相对低值 (48 Td) 的实验条件下计算的。放电实验条件为放电电流为60 mA，气压为230-530 Pa，气体流速为0.9 Slm -1 。