Radial Evolution of the Atmospheric Pressure Glow Discharge in Helium Controlled by Dielectric Barrier

The rachal evolution of atmospheric pressure glow discharge in helium is presented by numerical simulation. The calculations reveal the mechanism of two current peaks per half cycle. The first breakdown occurs firstly in the central region of the electrode, and then spreads to the edge, while the second breakdown ignites at the periphery firstly, and then propagates toward the discharge central region. The simulations indicate that radial electric fields and radial sheath play an important role in the evolution of the second peak. These results agree fundamentally with the experimental observations.     

辉光放电质谱新方法分析颗粒状金属铪

采用直流辉光放电质谱方法((dc-GD-MS)分析颗粒状((2mm×1mm×1mm)金属铪中的杂质元素.本方法解决金属铪样品尺寸太小难以直接进行辉光放电质谱分析的问题.采用聚四氟乙烯管(内径2.3 mm×外径3.2 mm)与医用注射器连接并密封接口,再将粒状铪置于管子前端(管长的1/3处),接着将PTFE 管水平插入已...     

人体模式静电放电对GaN基大功率发光二极管特性的影响

对GaN基大功率蓝光发光二极管(LED)分别施加了-200,-400,-600,-800,-1100和-1500V的反向人体模式静电打击,每次静电打击后,测量样品电学参数和光学参数的变化,研究了静电对LED可靠性的影响,并从理论上分析了相关衰减机理.结果表明,在-200,-400,-600和-800V的打击后,有明显的...     

Performances of RETGEM with resistive electrodes made of kapton foils

THGEM with resistive Kapton electrodes (RETGEM) has been developed to make the THGEM more tolerant to discharges. At higher gains with resistive electrodes, serious discharges may travel to the streamer mode, in contrast to violent sparks in conventional GEMs. These streamers are mild and less dangerous to the detector and the front-end electronics. RETGEM looks very promising, and its basic properties are being studied. Recently we developed and tested the THGEM with electrodes using 20 um thick resistive kapton foils. The new RETGEM performs at a lower discharge current, has a lower discharge probability, and has a good energy resolution of 27% and a high effective gas gain and long-term stability.     

空心阴极放电条纹特性的光谱诊断

利用发射光谱法,研究了圆柱型空心阴极放电条纹的特性.测量了条纹区的发射光谱,在此基础E计算得到r电子激发温度、相对电子密度和电子平均能量的空间分布特性.结果表明条纹区的光强、电子激发温度和电子密度均呈非等幅的周期性变化.与暗纹中心处相比,明纹中心具有较高的电子激发温度和较低的电子密度.由阴极向阳极,明纹中心处的电子激发温度幅值逐渐减小.此外,条纹区的电子激发温度随着电流的增加而增加.     

光谱法研究低气压空气介质阻挡放电均匀性

利用介质阻挡放电装置.在低气压空气中得到了均匀放电,并采用光谱法,研究了放电等离子体温度的空间均匀性.实验采集了氮分子光谱,采用氮分子第二正带系C3Ⅱu→B3Ⅱg计算振动温度;采用氮分子离子第一负带系计算转动温度(气体温度).实验发现,振动温度随电压增加而减小,而转动温度随电压增加而增大.等离子体振动温度和转动温度在空...     

氩气微腔放电中特性参数的数值模拟研究

本文采用二维自洽完全流体模型,针对阳极为通孔的高气压微腔放电结构,研究了微腔放电的参数特性.数值计算得到了氩气压强为100 Torr,放电稳态时的电势分布、电子数密度分布和电子温度分布等重要参数.模拟结果表明放电区存在显著的阴极鞘层结构,电子数密度的峰值达到10²⁰ m^-3,电子温度的量级为几个eV至十几eV,该结论与实验结果相一致.数值模拟合理的解释了微腔放电的基本原理. 关键词： 微腔放电 等离子体模拟 流体模型     

硅掺杂辉光放电聚合物薄膜的热稳定性研究

采用等离子体辉光放电聚合技术,在不同四甲基硅烷(TMS)流量条件下制备了硅掺杂辉光放电聚合物(Si-GDP)薄膜,采用傅里叶变换红外光谱、X射线光电子能谱和热重(TG)分析技术分析了不同TMS流量对Si-GDP薄膜结构与热稳定性的影响.结果表明:随着TMS流量在0–0.06 cm³/min范围变化,Si-GDP薄膜中Si的原子含量C_Si为0–16.62%;含Si红外吸收峰的相对强度随TMS流量的增加而明显增大;Si-GDP薄膜的TG分析显示,温度在300 ℃时,随TMS流量的增加,Si-GDP薄膜的失重减少,热稳定性增强. 关键词： 硅掺杂辉光放电聚合物薄膜 X射线光电子能谱 热稳定性