容性耦合等离子体的光谱诊断及其仿真模拟

Spectral Diagnosis and Simulation of Capacitive Coupled Plasma

等离子体电磁辐射谱携带了大量有关等离子体内部的放电信息。利用等离子体光谱诊断的原理和实验技术,可以得到等离子体的一些参数,如电子数密度和电子温度等,且具有适用范围广、灵敏度高、操作相对简单、无干扰、光谱信息丰富、对不同尺寸、均匀或非均匀等离子体都可诊断等优点。本文首先利用射频放电技术,电离密闭腔体内低压、惰性气体,制备等离子体。然后利用发射光谱诊断系统,测量了200~1 100nm范围内等离子体的发射光谱强度。分别利用玻尔兹曼斜率法以及沙哈-玻尔兹曼方程,计算了不同放电功率、不同气体压力下等离子体的电子温度和电子数密度,结果表明,当射频放电功率为100~800W,气体压力为30~600Pa时,等离子体电子温度范围约为1.4~1.9eV,电子数密度范围约为109~1011cm-3。最后将光谱诊断结果与COMSOL数值仿真结果进行对比,结果表明等离子体发射光谱的诊断结果与仿真结果相接近,利用光谱法可初步诊断出等离子体的放电参数,为后续研究等离子体性质提供依据。

The electromagnetic radiation spectrum of plasma carries a lot of information about the discharge inside the plasma.Based on the principles and experimental techniques for the plasma spectral diagnostics,some parameters such as electron number density and electron temperature can be obtained.It has the advantages of wide application range,high sensitivity,relatively simple operation,no interference,abundant spectral information,accurate diagnosis for different sizes uniform or non-uniform plasma,and so on.In this paper,we use the Radio Frequency(RF)discharge technology to ionize the low pressure inert gas in a closed chamber experimentally.Then,the emission spectrum intensity of plasma was measured in the range of 200~1 100 nm by an emission spectrum diagnosis system.The electron temperature was calculated using Boltzmann slope method with the RF power of 100~800 W,gas pressure under the condition of 30~600Pa.The results of electron temperature are about 1.4~1.9eV.Then the electron number density was calculated using Saha-Boltzmann equation in the same condition.It was found that the results of electron number density were approximately 109~1011 cm-3.Finally,the spectral diagnosis calculated results and COMSOL simulated results were compared.The results show that the spectroscopic diagnostic results for plasma are agree with COMSOL simulated results.The plasma discharge parameters can be obtained by spectral method,which provide a basis study for plasma properties.