精密电极结构实现小间隙大气压辉光放电离子源(英文)  

Realization of Atmospheric Pressure Glow Discharge Ion Source in Small Gap with Precise Electrode Structure

作　　者：刘坤[1] 王晓浩[2] 唐飞[2] 魏学业[1] 

机构地区：[1]北京交通大学电子信息工程学院,北京100044 [2]清华大学精密仪器与机械学系精密测试技术及仪器国家重点实验室,北京100084

出　　处：《纳米技术与精密工程》2010年第3期189-194,共6页Nanotechnology and Precision Engineering

基　　金：国家高技术研究发展计划(863)资助项目(2007AA04Z337);国家自然科学基金资助项目(60706030);国家自然科学基金仪器专项(20827002)

摘　　要：分析了电极结构精密度对大气压辉光放电稳定性的影响,设计并加工了一套高装配精度的线-筒型离子源.内外电极直径分别为0.16mm和4mm.当电压达到-3.5kV时电晕放电开始发生,放电电流波形为典型的特里切尔脉冲;当电压升高至-4.5kV时放电电流变为直流,表明进入辉光状态.通过放电电流波形可以清晰地观察到从电晕放电到辉光放电的过渡过程,并分析了其物理过程.放电实验表明,该装置可以稳定地实现大气压辉光放电,放电电流与施加电压成正电阻特性,而电极之间的电压在放电电流增大的情况下保持不变.这些放电特性与典型的低气压辉光放电一致.放电电流可达毫安量级,电离度较高,可有效提高检测灵敏度.质谱实验表明该离子源可以很好地离子化甲酸、乙酸、苯酚、苯甲酸等化学物质.The influence of electrode precision on the atmospheric pressure glow discharge was analysed. A line-cylinder ion source with precise electrodes was designed and fabricated. The diameters of the inner and outer electrodes were 0. 16 mm and 4 mm respectively. When the applied voltage reached3. 5 kV, the corona discharge started and the waveform of the discharge current was the typical Trichel pulse. When the applied voltage rose to4. 5 kV,the discharge current became direct current,showing that the discharge was completely operated in glow discharge mode. The transition from corona discharge to glow discharge can be clearly observed by the discharge current waveform. And the physical process was analysed. The discharge experiment shows that the system can generate stable atmospheric pressure glow discharge. The discharge current is in direct proportion to the applied voltage and the voltage between the electrodes keeps constant when the discharge current increases. All these discharge characters are in line with the low pressure glow discharge. The discharge current can reach the order of milliampere. Therefore,the ionization degree is higher enough to improve the detection sensitivity effectively. The mass spectrometer experiments show that the ion source can well ionize the chemicals such as formic acid,acetic acid,phenol,and benzoic acid and so on.

关 键 词：电极精密度 大气压辉光放电 敞开式离子源 

分 类 号：O461.21[理学—电子物理学]