本研究构建了一种可在大气压下工作的离子聚焦装置。此装置主要结构为一个矩形隧道,当在其上施加相同的电压,矩形隧道状的离子聚焦系统会形成指向中心线的电场,当离子进入到离子聚焦隧道后,便会向中心线附近运动。同时,离子在牵引电极与检测电极之间形成的电场的作用下,向检测电极运动。利用仿真软件SIMION8.0仿真验证了此离子聚焦装置的有效性。从检测电极的离子电流入手,提出了一种可以在大气压下判断离子空间分布的新方法。利用紫铜、环氧树脂板、电木板等材料设计加工了此离子聚焦装置,聚焦装置的尺寸为5 mm×5 mm×3.5 mm;检测电极直径为0.8 mm;相邻电极间的中心距为1.6 mm。结合实验室自行设计的离子源进行了静电计检测实验。结果表明;中间电极上的电流约为66 nA,超出其它电极电流一个数量级,离子强度可提高6倍以上。仿真以及实验数据充分说明此装置具有离子聚焦的功能。
A ion focus device that can work under ambient conditions was developed. The device is a rectangular tunnel with the same voltage. The electric field is produced by the ion focus system points to the center line of the rectangular tunnel. When the ions enter the ion focus tunnel, they move to the center line under the force of electric field. Thus, this device can focus the ions. Meanwhile, the ions move to the detector by the electric field produced by traction electrode and detector. Its effectiveness is verified by the simulation software SIMION8.0. Considering the ion current of detection electrodes, a new method of decision for the ions spatial distribution under ambient conditions was proposed. On the basis, the device was designed and processed by uing red copper, epoxy board and Bakelite. The size of the ion focus device is 5 minx5 mm x3.5 ram. The diameter of the detector electrode is 0.8 ram, and the center distance of adjacent electrodes is 1.6 ram. The electrometer experiment was done using the ion source which was designed by our laboratory. The results show that the ion current of middle electrode is about 66 hA, exceeds a magnitude of other electrodes. And the mass spectrum experiments were performed, and the results indicate that the ion intensity can be enhanced 6 times with the ion focus system. The simulation and experiments verify that the effectiveness of ion focus sufficiently.