Simulation of Unidirectional Ion Ejection in an Asymmetric Half-Round Rod Electrode Linear Ion Trap Mass Analyzer

Journal Article · Mon Oct 15 04:00:00 EDT 2018 · Journal of the American Society for Mass Spectrometry

DOI:https://doi.org/10.1007/S13361-018-2014-Y· OSTI ID:22776835

Wu, HaiYan; Zhang, LiPeng; Zhang, ZaiYue; Qian, Jie; Zhang, ShuGuang; Zhang, YingJun; Ge, SaiJin; Li, XiaoXu ^[1]

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1. Soochow University, School of Mechanical and Electrical Engineering (China)

An asymmetric trapping field was generated from an asymmetric half-round rod electrode linear ion trap (A-HreLIT), and its performance of unidirectional ion ejection was studied. Two different asymmetric structures of A-HreLITs were constructed, one rotating y electrode pairs toward an x electrode with an angle θ, and the other stretching one x electrode with a distance α. The center of trapping field was displaced away from the geometrical center of the ion trap, defined to be the midpoint along the axis of y between x electrodes, which leads to unidirectional ion ejection through one x electrode. Computer simulations were used to investigate the relationship between asymmetric geometric parameter of θ (or α) and analytical performance. Both structures could result in similar asymmetric trapping fields, which mainly composed of dipole, quadrupole, and hexapole fields. The dipole and hexapole fields were approximately proportional to the asymmetric geometric parameter of rotation angle θ (or stretch distance α). In simulation, ion trajectories and ion kinetic energy were calculated. For ions with m/z 609 Th, the simulation results showed that mass resolution of over 2400 (FWHM) and ion unidirectional ejection efficiency of nearly 90% were achieved in an optimized A-HreLIT. Ion detection efficiency of A-HreLIT could be improved significantly with only one ion detector, while maintaining a considerable mass resolution. Furthermore, the A-HreLIT could be driven by a traditional balanced RF power supply. These advantages make A-HreLIT suitable for developing miniaturized mass spectrometer with high performance. .

• OSTI ID: 22776835
• Journal Information: Journal of the American Society for Mass Spectrometry, Journal Name: Journal of the American Society for Mass Spectrometry Journal Issue: 10 Vol. 29; ISSN 1044-0305; ISSN JAMSEF
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
COMPUTERIZED SIMULATION
ION DETECTION
MASS RESOLUTION
MASS SPECTROMETERS
QUADRUPOLES