Opt Lett. 2018 Nov 1;43(21):5343-5346. doi: 10.1364/OL.43.005343.
A cavity-enhanced Thomson scattering (CETS) diagnostic has been developed to perform electron density and temperature measurements in low-density weakly ionized discharges. The diagnostic approach is based on generating a high-power beam in an optical build-up cavity and using the beam as a light source for Thomson scattering from plasma housed within the cavity. In our setup, a high-power (∼5 W) fiber laser at 1064 nm allows an intra-cavity power of 11.7 kW in a two-mirror cavity for measurements in the plume of a BaO hollow cathode discharge. A study of plasma density and temperature was performed at various operating conditions. Electron densities and temperatures in the range of ∼10 cm and ∼3 eV were measured, respectively. The high signal-to-noise ratio (SNR) of the present measurements (SNR=1100) suggests the ability to measure significantly lower density plasmas in the range of ∼3×10 to 3×10 cm, thereby extending current laser Thomson scattering diagnostic capabilities.
一种基于增强型汤姆逊散射（CETS）的诊断方法已经被开发出来，用于在低密度弱电离放电中进行电子密度和温度测量。该诊断方法基于在光学建立腔中产生高功率光束，并使用该光束作为等离子体内部的汤姆逊散射光源。在我们的设置中，1064nm 的高功率（约 5 W）光纤激光允许在双反射镜腔中实现 11.7kW 的腔内功率，用于测量 BaO 空心阴极放电羽流中的等离子体。在各种工作条件下进行了等离子体密度和温度的研究。分别测量到的电子密度和温度范围约为 10 cm 和 3 eV。目前测量的高信噪比（SNR=1100）表明，能够测量范围约为 3×10 到 3×10 cm 的低得多的密度等离子体，从而扩展了当前激光汤姆逊散射诊断能力。
