We report the results of fundamental studies of an atmospheric-pressure microwave plasma sustained in nitrogen. Plasma composition was modelled using chemical equilibrium software, with the measured temperature used as input for the program. The modelled electron density agreed well with the electron density measured in Thomson scattering experiments. The various temperatures measured (electronic excitation, electron, and rotational) were comparable, and we argue that the N2 microwave plasma is close to local thermodynamic equilibrium (LTE). This close-to-LTE behaviour was used as a basis to calculate the emission spectra of selected elements; the calculated spectra were compared with measured library spectra, and good agreement was found.

中文翻译：

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氮气中用于原子发射光谱分析的常压微波等离子体的基础研究

我们报告了在氮气中维持的大气压微波等离子体的基础研究结果。使用化学平衡软件对血浆成分进行建模，并将测得的温度用作程序的输入。模拟的电子密度与Thomson散射实验中测得的电子密度非常吻合。测得的各种温度（电子激发，电子和旋转温度）是可比较的，并且我们认为N2微波等离子体接近于局部热力学平衡（LTE）。这种接近LTE的行为被用作计算所选元素的发射光谱的基础。将计算出的光谱与测得的谱库光谱进行比较，发现吻合良好。