Jaiswal S, Aguirre E M, Prakash G Veda
Department of Physics, Auburn University, Auburn, AL, 36832, USA.
Department of Chemical and Biological Engineering, Princeton University, Princeton, NJ, 08544, USA.
Sci Rep. 2021 Jan 21;11(1):1893. doi: 10.1038/s41598-021-81488-x.
Creation of the "auroral" green line, a fascinating occurrence commonly observed in the upper atmosphere, has long been a difficult endeavor, especially at atmospheric pressure. Here we report strong emission of the "auroral" green line for the first time in a kHz frequency, linear field atmospheric pressure plasma jet system. The device used 99.999% pure argon as a working gas for the plasma generation. Optical emission spectroscopy measurements of the after discharge region show the existence of 557.7 nm emission which corresponds to the transition O([Formula: see text]S)-O([Formula: see text]D). The intensity of the produced green line is strong enough that the entire plasma plume in the ambient air is visible as a green plasma. We provide the chemical reactions of O([Formula: see text]S) production in the plasma and the estimation of the density of the O([Formula: see text]S) metastable state using the kinetic reactions. Further, the O([Formula: see text]S) emission is characterized by changing the flow rate of argon, applied voltage and electrode gap. The adequate plasma length ([Formula: see text]) along with the production of a variety of reactive components viz; OH, [Formula: see text] and oxygen (777 nm) make this configuration useful for applications such as: blood coagulation, cancer treatment, sterilization, and waste treatment. Moreover, this setup can be potentially used as a test bed for the in-depth understanding of plasma chemistry relevant to the aurora and comet tails using a laboratory setting.
“极光”绿线的产生是高层大气中常见的一种奇妙现象，长期以来一直是一项艰巨的任务，尤其是在大气压下。在此，我们首次报道在千赫兹频率的线性场大气压等离子体射流系统中强烈发射出“极光”绿线。该装置使用99.999%的纯氩气作为产生等离子体的工作气体。对放电后区域的光学发射光谱测量表明存在557.7纳米的发射，这对应于O([公式：见正文]S)-O([公式：见正文]D)的跃迁。所产生的绿线强度足够强，以至于周围空气中的整个等离子体羽流可见为绿色等离子体。我们给出了等离子体中O([公式：见正文]S)产生的化学反应，并利用动力学反应估算了O([公式：见正文]S)亚稳态的密度。此外，通过改变氩气流量、施加电压和电极间隙来表征O([公式：见正文]S)发射。合适的等离子体长度([公式：见正文])以及多种活性成分即；OH、[公式：见正文]和氧气(777纳米)的产生使得这种配置可用于诸如：血液凝固、癌症治疗、消毒和废物处理等应用。此外，这种装置有可能用作试验台，以便在实验室环境中深入了解与极光和彗尾相关的等离子体化学。
