氩气/空气ICP放电现象研究和基于H_β光谱展宽的微波干涉电子密度诊断方法  

Study on Form of Ar/Air ICP and A Microwave Diagnostics Based on the H_β Spectrum Broadening

作　　者：魏小龙[1] 徐浩军[1] 林敏[1] 宋慧敏[1] 陈茂才[2] 

机构地区：[1]空军工程大学航空等离子体动力学国防科技重点实验室,陕西西安710038 [2]中国船舶重工集团公司第七〇四研究所,上海200072

出　　处：《光谱学与光谱分析》2016年第4期1170-1174,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(11472306)资助

摘　　要：闭式腔体ICP是解决飞行器等离子体局部隐身的可行方案,其电子密度Ne在电磁波入射方向上的分布是影响其电磁波衰减效果的关键因素。对此,开展了在30.8cm×30.8cm×5.8cm石英腔体内的ICP放电实验,通过实验研究了空气/氩气ICP的E-H模式跳变的物理现象,通过测量得到了空气/氩气环状ICP的宽度和覆盖面积比例随电源功率变化的规律,并给出了上述实验现象的理论解释。为了得到平面型ICP的电子密度在微波入射方向的分布,提出基于Hβ光谱展宽的微波干涉分布诊断法,分别对平面真空腔室内空气/氩气ICP的电子密度在电磁波入射方向上的分布进行了诊断,通过H_β(486.13nm)Stark展宽拟合和微波干涉过程分别获取电子密度分布函数的两项参数,得到了电子密度分布随放电功率变化的曲线。实验可得到电子密度范围为0.5×10^(11)~3.2×10^(11) cm^(-3)的环状ICP源,实验结果表明,ICP的电子密度受气体种类,射频功率影响较大,峰值电子密度接近ICP的中心位置,通过比较发现,氩气的电子密度较高,有效拟合区域较窄,空气的有效拟合区域较宽,覆盖面积较大。The ICP in closed quartz chamber is an effective solution to local stealth of aircraft.The attenuation of the electromagnetic wave is strongly affected by distribution of electron density in incidence direction.In this paper,an experiment that the planar ICP discharged in all-quartz chamber（30.8cm×30.8cm×5.8cm）was conducted.The E-H mode transition of Ar/Air ICP was observed,and the width and the proportion of ICP area versus the RF power were measured.Such physical phenomena were explained rationally by ICP-source theoretical model.A new microwave diagnostics is presented based on the H_β spectrum broadening and the characteristics of planar-coil ICP.It is used to diagnose the spatial electron density distribution of Ar/Air in incidence direction.The parameters of electron density distribution function in the incident direction are separately solved by the fitting results of the H_β stack broadening and microwave interferometer.And the curves of electron density distribution versus RF power are obtained.We obtain a stable ring plasma source with electron density varying from 0.5×10^11～3.2×10^11 cm^-3.The experiment demonstrates that electron density is prominently affected by the RF power and gas species.The peak value of electron density is positioned near the center of ICP.It is shown that the electron density of Ar ICP is higher than the air,but the area of air ICP is larger through comparing the curves of Ar/Air electron density.

关 键 词：等离子体隐身 电感耦合等离子体 石英腔体 电子密度 

分 类 号：O657.3[理学—分析化学]