小型空间同位素质谱仪器的搭建  

Design of a Miniature Space Isotope Mass Spectrometer

作　　者：王学智 孙健 杨喆 李刚[4] 苏海波 谭国斌 高伟 WANG Xue-zhi;SUN Jian;YANG Zhe;LI Gang;SU Hai-bo;TAN Guo-bin;GAO Wei(Institute of Mass Spectrometer and Atmospheric Environment,Ji’nan University,Guangzhou 510632,China;Guangzhou Hexin Instrument Co.,LTD,Guangzhou 510530,China;Science and Technology on Vacuum Technology and Physics Laboratory,Lanzhou Institute of Physics,Lanzhou 730000,China;Northeast University,Shenyang 110819,China)

机构地区：[1]暨南大学质谱仪器与大气环境研究所,广东广州510632 [2]广州禾信仪器股份有限公司,广东广州510530 [3]兰州空间技术物理研究所,真空技术与物理重点研究室,甘肃兰州730000 [4]东北大学,辽宁沈阳110819

出　　处：《质谱学报》2023年第3期357-366,I0002,共11页Journal of Chinese Mass Spectrometry Society

摘　　要：空间同位素探测对人类进一步探索太空有着重要意义。磁质谱具有分辨率高、动态范围宽、丰度灵敏度高等优点,主要用于同位素定量分析。然而,传统的磁质谱仪体积庞大、能耗高、造价及维护费用昂贵,使其在空间探测领域的应用面临着较大挑战。本研究设计并搭建了一套小型化的马赫型磁电双聚焦质谱仪,主要结构包括电子轰击电离源、静电分析器、磁分析器以及荧光屏检测器。质谱仪的物理部分尺寸24 cm×12 cm×9 cm,磁分析器场强0.85 T,采用荧光屏检测离子信号。实验采用标准氮气(m/z28)测试仪器性能,经离子成像处理软件计算可得m/z 28处的分辨率为65,灵敏度为3.28×10^(4) V/Pa,可检测质量范围达70 u。通过对仪器的关键部件进行小型化设计,可满足空间同位素探测任务的需求。Isotopes in space contain a lot of scientific information,such as whether there is water on the surface of the lunar,and how the composition of water on the moon differs from water on Earth.Through qualitative and quantitative analysis,the unknown field of human beings can be further explored.Double-focusing magnetic mass spectrometer(DFMS) is a type of magnetic MS that can simultaneously focus the energy and mass of ions.DFMS is widely used in isotope detection,geological element analysis and other fields because of its large dynamic range and high resolution.But traditional magnetic MS is not suitable for space exploration mission because of its large size and weight.In this work,a miniaturized Mattauch-Herzog type of DFMS was designed and constructed.The size of the physical part of this instrument was 24 cm×12 cm×9 cm.The physical part included electron impact ionization source,electrostatic analyzer,magnetic analyzer and phosphor screen detector.The ion source used in this study was a classical Neal electron impact ionization source,which adopted a lightweight design with a size of 80 cm~3 and a weight of about 90 g,and an alpha slits was adopted to limit the angle of ions beam.The electrostatic analyzer adopted a curved structure design,which was divided into upper and lower poles.The deflection angle of the electrostatic field was 31.8°,and the two poles were kept at a certain distance so that the electric field was evenly distributed.The magnetic analyzer was made of permanent magnet material,which had the advantages of magnetically stable and uniform intensity of internal magnetic.A layer of metal shell was installed outside the magnet to reduce the effect of the dispersion field.The deflection radius at the center of the magnetic analyzer used in this instrument was 62 mm,the ion deflection angle was 90°,and the magnetic field strength was 0.85 T.Furthermore,the phosphor screen detector consists of three circular microchannel plates(MCPs) to amplify the received ion electrical signals,and through th

关 键 词：同位素质谱 小型化 磁分析器 电子轰击电离源 

分 类 号：O657.63[理学—分析化学]