利用离子风实现后吸式进样与电离集成的离子源

Ion source with posterior suck sampling and ionization by ionic wind

针对现用离子源工作时需外接庞大复杂的供气装置,不利于便携的不足,提出了一种基于离子风的敞开式离子源和微型气泵集成系统。设计了一种新型阵列式针-柱放电电极结构,其可以在大气压下实现敞开式离子源和微型气泵双重功能。选用0^-20 000V的负直流高压供电电源,10mm的针-柱间距,分别对单排针-单柱,单排针-双柱,双排针-双柱3种放电电极结构进行电晕放电,并采用testo 405-V1风速计进行风速测量。结果表明,双排针-双柱产生的风速最大。采用COMSOL多物理场仿真软件对3种电极结构进行离子风仿真,并与实验结果对比,结果吻合良好。以双排针-双柱电极结构进行了离子源和微型气泵集成系统实验。结果显示:该结构放电产生的离子风最大为2.11m/s,可以将装置后端处的乙酸样品吸入;电离产生的最大电流信号为-10nA左右,表明该装置实现了电离功能。本文所设计的离子源和微型气泵集成系统,实现了后吸式进样并电离,省去了庞大复杂的供气装置,有望应用于便携式分析仪器中。

As existing ion source requires a complex external huge gas supply and is not convenient to be carried,this paper proposes a integrated system by an opened ion source and a micro gas pump based on ionic wind.A new needle array-cylinder discharge electrode structure was designed to realize the double functions of the open ion source and the micro air pump in ambient air.When the power supply was served as a negative DC high voltage of 0--20 000 V,and the distance between the nee-dle and the cylinder was 10 mm,the corona discharge was implemented by three types of discharge electrode structures respectively：single-array-needle and single-cylinder,single-array-needle and double-cylinder,double-array-needle and double-cylinder,and the wind velocity was measured by the testo405-V1anemometer。The result shows that the maximum wind velocity is produced by the double-array-needle and double-cylinder structure.By using three types of electrode structures,COMSOL multi physic simulation software was applied to simulation of the ion wind and the results show that the simulation is coincided with that of the experimental results well.Based on the double-array-needle and double-cylinder structure,the integrated system experiment of the ion source and the micro air pump was conducted.The results demonstrate that the maximum ion wind generated by the structure discharge is 2.11m/s,which can suck an acetic acid sample at the bottom into the device.Moreover,the maximum electric current value reaches about-10 nA tested by the Faraday cup,which shows that the device realizes the ionization function.In conclusion,the integrated system of the ion source and the micro air pump in this paper realizes posterior suck sampling and ionization,omits a huge complex external gas supplies,and is expected to be applied to portable analytical instruments.