用于高场非对称波形离子迁移谱系统的阵列式微法拉第筒离子检测器  

Array micro Faraday cup ion current detector for FAIMS

作　　者：唐飞[1] 王晓浩[1] 张亮[1] 

机构地区：[1]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：《光学精密工程》2010年第12期2597-2602,共6页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.60706030);国家自然科学基金仪器专项资助项目(No.20827007);国家863高技术研究发展计划资助项目(No.2007AA04Z337)

摘　　要：提出了一种可减小高场非对称波形离子迁移谱(FAIMS)系统体积的阵列式微法拉第筒离子检测器,该检测器具有结构简单、稳定性好、噪声小、量程大、可在大气压条件下工作等优点。阵列式微法拉第筒包括栅电极、敏感电极、屏蔽电极3部分,其中敏感电极由数十个直径为200μm的硅圆柱交错排列而成。通过典型的MEMS工艺制作,法拉第筒与平板型FAI MS系统的MEMS工艺完全兼容。Fluent仿真结果表明,这种阵列式的设计,气体运动阻力较小,流场分布有助于载气中离子被充分吸收。与KEITHLEY237电流表级联后,测得阵列式微法拉第筒的噪声水平在0.5 pA以下。对丙酮样本进行了实验测试,结果显示其输出信号为210 pA左右,表明该阵列式微法拉第筒满足FAIMS系统的要求。An array micro Faraday cup ion current detector is presented.With its design,a simpler and smaller High-field Asymmetric Waveform Ion Mobility Spectrometry（FAIMS） could be achieved.Compared with other types of detectors,it has advantages in simplicity,stability,low noise,high measuring range,and atmosphere compatibility.The Array Micro Faraday Cup（AMFC） is made up of three parts：grid electrode,sensing array and shielding electrode,in which the sensing array is formed by dozens of 200-micron-diameter silicon cylinders in a staggered arrangement.The structure of the micro Faraday cup can be fabricated in a typical MEMS fabrication process,for it is totally compatible with the planar FAIMS micro chip.Fluent simulation results show that the design could realize a small fluid resistance force,and the flow field of the carrier gas is in favor of a better absorption of the ions.When it is combined with a KEITHLEY 237 electrometer,the noise level of the AMFC is about 0.5 pA,while the output signal of an acetone sample is about 120 pA.Obtained results show that the AMFC satisfies the requirements of FAIMS systems.

关 键 词：高场非对称波形离子迁移谱 微机电系统 法拉第筒 离子检测器 微弱电流 

分 类 号：TL811[核科学技术—核技术及应用]