title: Design and study of an atmospheric pressure ion funnel by computer simulations.
abstract: BACKGROUND
  An atmospheric pressure ion funnel (APIF) has been developed to transfer and focus ions at atmospheric pressure. This ion funnel can be used as an interface connecting the ion source and the mass spectrometer detector.
  
  
  METHODS
  The APIF designs were studied mainly by using computer simulations. Different APIF configurations with various geometrical and electrical parameters were analyzed. Investigation of the electrical field and ion transmission characteristics of the APIF was carried out using SIMION 8.0.
  
  
  RESULTS
  The APIF exhibits good ion-guiding performance with transmission efficiency of >90%. An approximate formula for determining the optimal parameters of the APIF has been derived by theoretical calculation.
  
  
  CONCLUSIONS
  When both the geometrical and the electrical parameters are optimized, the APIF can provide high ion transmission efficiency. In addition, the proposed empirical formula is helpful in guiding the design of APIFs.
authors.affiliation: Division of Advanced Manufacturing, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, China.
authors.forename: Quan
authors.initials: Q
authors.lastname: Yu
authors.affiliation: Division of Advanced Manufacturing, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, China.
authors.forename: Zhaoliang
authors.initials: Z
authors.lastname: Diao
authors.affiliation: Division of Advanced Manufacturing, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, China.
authors.forename: Kai
authors.initials: K
authors.lastname: Ni
authors.affiliation: Division of Advanced Manufacturing, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, China.
authors.forename: Xiang
authors.initials: X
authors.lastname: Qian
authors.affiliation: State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments and Mechanology, Tsinghua University, Beijing, 100084, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Tang
authors.affiliation: Division of Advanced Manufacturing, Graduate School at Shenzhen, Tsinghua University, Shenzhen, 518055, China.
authors.forename: Xiaohao
authors.initials: X
authors.lastname: Wang