Characterization of an RF-driven argon plasma at atmospheric pressure using broadband absorption and optical emission spectroscopy
Characterization of an RF-driven argon plasma at atmospheric pressure using broadband absorption and optical emission spectroscopy
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DOI：
10.1063/5.0035488
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发表时间：
2020-12
影响因子：
3.2
通讯作者：
G. Nayak;M. Simeni Simeni-M.-Simeni-Simeni-2125881320;J. Rosato;N. Sadeghi;P. Bruggeman
中科院分区：
文献类型：
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作者：
G. Nayak;M. Simeni Simeni-M.-Simeni-Simeni-2125881320;J. Rosato;N. Sadeghi;P. Bruggeman
氩气中的大气压等离子体特别令人感兴趣，这是由于产生了高度激发和反应性的物质，从而能够实现许多等离子体辅助应用。在这方面的贡献，我们报告的绝对光学发射和吸收光谱的射频（RF）驱动的电容耦合氩辉光放电中操作的平行板配置。这使得所有关键参数的研究，包括电子密度和温度，气体温度，以及原子在高电子激发态的绝对密度。空间和时间平均的电子密度和温度是从测量的绝对强度的电子原子韧致辐射在可见光范围内。考虑到非麦克斯韦电子能量分布函数，电子温度（Te）为2.1 eV，电子密度（ne）为1.1 × 1019 m − 3。用宽带吸收光谱法测量了纯Ar和Ar/He混合气体中Ar的亚稳态（1 s5和1 s3）和共振态（1 s4和1 s2）原子的时间平均和空间分辨绝对密度. 1 s 5亚稳态原子在鞘层附近的密度最大，最大值为8 × 10 17 m − 3，而所有其他1 s态的密度最多为2 × 10 17 m − 3。讨论了这些原子的主要产生和损失机制，特别是辐射俘获的作用。我们的结论与比较的等离子体性质的氩RF辉光放电与更常见的他等效，并突出他们的差异。
Atmospheric pressure plasmas in argon are of particular interest due to the production of highly excited and reactive species enabling numerous plasma-aided applications. In this contribution, we report on absolute optical emission and absorption spectroscopy of a radio frequency (RF) driven capacitively coupled argon glow discharge operated in a parallel-plate configuration. This enabled the study of all key parameters including electron density and temperature, gas temperature, and absolute densities of atoms in highly electronically excited states. Space and time-averaged electron density and temperature were determined from the measurement of the absolute intensity of the electron-atom bremsstrahlung in the visible range. Considering the non-Maxwellian electron energy distribution function, an electron temperature ( T e) of 2.1 eV and an electron density ( n e) of 1.1 × 10 19 m − 3 were obtained. The time-averaged and spatially resolved absolute densities of atoms in the metastable ( 1 s 5 and 1 s 3) and resonant ( 1 s 4 and 1 s 2) states of argon in the pure Ar and Ar/He mixture were obtained by broadband absorption spectroscopy. The 1 s 5 metastable atoms had the largest density near the sheath region with a maximum value of 8 × 10 17 m − 3, while all other 1s states had densities of at most 2 × 10 17 m − 3. The dominant production and loss mechanisms of these atoms were discussed, in particular, the role of radiation trapping. We conclude with comparison of the plasma properties of the argon RF glow discharges with the more common He equivalent and highlight their differences.