Insights into spatial inhomogeneity in an oxygen plasma from cavity ringdown spectroscopy
Insights into spatial inhomogeneity in an oxygen plasma from cavity ringdown spectroscopy
复制标题
从腔衰荡光谱中洞察氧等离子体的空间不均匀性
DOI：
10.1088/1361-6595/ad1a79
复制
发表时间：
2024
影响因子：
3.8
通讯作者：
Rogers S
中科院分区：
文献类型：
--
作者：
Rogers S
利用光腔衰荡光谱研究了100 mTorr（13.332 Pa）气压下电感耦合等离子体中O2（X）的v = 0和1振动能级的平移和转动温度。当等离子体功率增加时，所有探测到的转动状态显示出明显的温度增加：在固定功率下，对于v = 1的转动状态，平移温度似乎最大（J = 7、16、17、22），低能态最低（J = 1，18，19）; v = 0的高激发转动态（J = 28，30，31）显示中间行为。旋转温度值的表现类似。这些观察结果与等离子体不均匀性的影响是一致的，并且可以用一个简单的一维模型来解释，由此，通过合理的配置文件和相应的视线平均密度和温度计算，近似了整个腔室（和臂）的各种物质的压力，温度和摩尔分数。这个基本模型在重现O 2（X，v = 0）和O（3 P）密度的观测结果方面相当成功。事实上，解决几个旋转过渡允许等离子体内的空间变化，从视线平均测量推断是一个非常强大的结果，可能是在未来的工作中非常有用的。
Cavity ringdown spectroscopy has been used to investigate the translational and rotational temperatures of the v= 0 and 1 vibrational levels of O 2 (X) in an inductively coupled plasma at 100 mTorr (13.332 Pa) pressure. All rotational states probed display a clear increase in temperature as plasma power increases: at fixed power, the translational temperature appears largest for rotational states in v= 1 (J= 7, 16, 17, 22) and lowest in the low energy states (J= 1, 18, 19) in v= 0; highly excited rotational states (J= 28, 30, 31) of v= 0 show intermediate behaviour. The rotational temperature values behave similarly. These observations are consistent with the effects of plasma inhomogeneity and can be interpreted with a simple one-dimensional model whereby the pressure, temperature and mole fractions of the various species across the chamber (and arms) are approximated with rational profiles and the corresponding line-of-sight averaged densities and temperatures calculated. This basic model is reasonably successful at reproducing the observations for O 2 (X, v= 0) and O (3 P) densities. The fact that resolving several rotational transitions allows spatial variations within the plasma to be inferred from line-of-sight averaged measurements is an extremely powerful result that could be of great utility in future work.